20 septembrie 2007

Un nou site cu si despre radioamatori

|Tot scobind prin maruntaiele internetului dupa niste documentatii referitoare la hobby-ul meu, radioamatorismul si statiile de emisie receptie, am dat peste un site tare misto si cu niste perspective de dezvoltare net superioare! Este vorba de www.radioamator.eu.
Site, e cam prea mult spus. Practic, este un forum bine structurat, asezonat cu o galerie de imagini care, prevad, se va dezvolta in lunile care urmeaza.
Ideea de la care porneste este buna, in romania existand destul de putine site-uri cu acest profil iar cele care exista deja sunt usor infantile sau prea batranicioase, in opinia mea. Era timpul sa apara ceva axat pe continut si nu pe aspect, iar baietii (sau fetele) care au pus asta pe picioare imi dovedesc ca stiu cam ce se poate scoate de la un simplu motor de forum!
Sunt curios sa vad cum va evolua pe viitor!
Galeria de imagini este aici.
Site-ul necesita o inregistrare cu o adresa valida de e-mail. Hei, asta poate fi un motiv de temere caci acea adresa este posibilsa inceapa sa fie sufocata de spam, dar, what the hell, eu am deja o adresa de email facuta special pentru inregistrari pe site-uri! Si nu sufera prea mult!

18 septembrie 2007

Echolink Bucharest

Due to the timless life I have, I was unable to run on a permanent basis this Echolink node.
Fortunately, it is another one here, full time available, YO3KYD which cover the city of Bucharest!
You are invited to access this node!
Freq: 145.550 FM
Node number: 379326

Meantime, I found a Motorola GM900 radio for the UHF echolink node!!! I hope I'll find some time to setup the UHF node here in Bucharest!
12 aug.2008

73! de yo3hjv

This week-end I started again the Echolink 2m node.

There was no more echolink node for Bucharest in he past year due to some malfunction in the yo3hcv-l we experienced. That node was running for more than 3 years with the help of 2 friends, YO3FUU and YO3HCV. It's a pitty because we have had a "vanity" node number, 144.900 which was the frequency on which we run the VHF node.
Now I started the VHF node, but the one designated for UHF, in 144.300 Mhz. I plan to find a UHF Motorola radio to make it work under YO3HJV-L callsign, but I think this will be next year as will be a entirely private investment.

I intend to keep this node operational as long as I can.

Here are the info's:
Frq: 145.300mhz, CTCSS 103,5, node number:43750
Max key down: 210 sec, for both TX and RX to and from Internet.
Output power: 50W, antenna heigh is around 45m, so I will expect a good coverage of 80km around.
The radio is Kenwood TS2000X, Rigexpert+IBM Thinkad T43.
The node is in beta. I plan to use a dedicated radio I have around, Icom IC2100H with a dedicated antenna. Something like an open dipole for a good omnidirectional coverage.
Please feel free to call !

73! de YO3HJV

04 septembrie 2007

Alinco DJ-G5

Big, very "tech-looking" radio but versatile and sensitive!

I have owned the radio for more than 3 years and I sold it... Again, like with my FT-857D, this radio is back in my shack after passing a few fellow hams.
First, I have to say that the original stock antenna is one of the worst I have ever seen! But with a real dual band antenna, the things are changing! I used a Diamond RH771S and now I use a Kathrein K7151219 GainFlex antenna.

What I like

Is a real dual bander! This means that you can listen simultaneous on two different frequencies! The possible combinations are: V/U (reccomended), V/V, U/V, U/U. Add to this the two VFO's per receiver and you have a lot of possibilities!

Feeling. When you keep it in your hand, it feels very solid. The back-case is real-metal.

Cross band repeater. This radio performs a cross band repeater and it does well! This is usefull when in mobile operations, and emergency communications when a external antenna will be a plus! And a nice feature is that you can monitor the communications directly in the radio's speaker. Can work as one way repeater or two way cross repeater. Also is full duplex capable!

Battery life. The radio have a extended range of operating voltage. Somewhere between 4V-13V. So, a 9,6V EBP-36N will last about a week on a moderate receiving operation.

Simplicity in operation. The radio isn't "menu driven". The functions are very easy accesed from F+Key.

Good audio reports. On both receiving and transmitting!

BNC connector for antenna. Is very easy to connect a external antenna for mobile use. Also very easy to replace broken connector.

Good locking mechanism for battery.

Good place for external PTT Microphone/Speaker.

Front end attenuator. This can improve the IMD figure when the radio is use with a mobile external antenna.

Good AM receiving. I often monitor the Airband and the radio is good on this. But not with the stock antenna!
Normal 3.5mm jack for headphones. Is easy to use regular headphone, for one ear, to monitor when walking... No expensive accessory for listners!

I don't like

The radio becomes very hot. Even the power is set to M, the radio will be hot on about 5 minutes of transmission, so if you plan to use it as a cross band repeater, you have to put a fan on the radio!

The keypad inscriptions will be erased in months of moderate usage though the inscriptions above de key (the one on the case) will last for years!

Poor PTT, MON and secondary PTT switches and rubber. The rubber will break. I changed the PTT microswitch after 2 years.

Volume and Squelch controls. I wish I have knobs for volume and squelch for the two sections!

No alpha tags on memory. This can be annoying when you are a "listener" like I am. Hard to remember what frequency is!

No CAT. Can't programm with a cable tough there is a way to save the channels by Air Cloning. You have to record the DTMF's which are sent by the radio with another radio.

Other things about this radio

Is very solid, the screen light can be set on continuous by pushing F+LAMP, the radio have a lot of paging options. Is slow on scanning so I use it to monitor two frequencies instead of scanning. Also a nice feature is the band scope which works OK because it used the other receiver to "take the picture".
By default, the number of memory channels alocated for the two sections is equal but You can change this very easy. (by default 80+80 memory channels).
The radio use in the final stage hybrid modules and the measurements show around 7W on VHF and 6 in UHF when use 12V. Again, the radio will be really hot!

I am searching for a new case for the radio, new keypad and rubbers for PTT.

Overall, the radio is a "power-horse". Is best for backpacking but to heavy for pants! Alinco did a good job. This may be "the last true dual bander" from Alinco!

Here are the specifications from Alinco:

VHF/UHF FM Twin Bander

Tx: 144.000-147.995/438.000-449.995 MHz
Rx: 108.000-173.995 AM/FM /438.000-449.995 MHz

  • Channel Scope
  • Full duplex between VHF & UHF
  • CTCSS Tone Squelch
  • Memory channels VHF 80 + UHF 80
  • DSQ selective call
  • 20 auto-dialers
  • 2W output or 5W with the optional EBP-36N battery
  • U x U/V x V
  • Compact 57 x 139 x 27.5 mm body
  • Sweep Scan
  • X-band repeater
  • Direct freq. entry through keypad
73! de yo3hjv

I can't attach here the user and service manual but you can ask me to send by e-mail in pdf. format.

Below, the schematics in
gif format:

03 septembrie 2007

How to disable System Beep - Dezactivarea sunetului de sistem

Tested on XP Home Edition and XP-Pro SP2.

This post is useful for Digimodes especially when the computer's audio output is wired directly into the transceiver and VOX is used for PTT. Maybe you noticed that a system error (like two keys on the keyboard pushed simultaneous) give a loud "ding" sound into the speaker. On a big desktop PC, the system beep will be heard from the main board buzzer but on a laptop, the sound will be generate directly into the speakers. It's shure that we don't want to be sent over the air by VOX feature on the transceiver!
So, how to disable this without compromising the speakers?
First, go to START>SETTINGS, then select SYSTEM.
On Device manager window, in the menu bar, select VIEW and then, SHOW HIDDEN DEVICES. Look in the list and you will see "BEEP" listed. Right-click on it!
DISABLE is the magic word!
So, that was!
73! de yo3hjv

Testat pe Windows XP Home Edition si Windows XP-PRO SP2

Urmatoarele instructiuni sunt utile celor care folosesc un laptop conectat la un transceiver pentru modurile digitale, iar pentru trecerea in emisie se foloseste functia VOX.
Dezactivarea alarmei de sistem (un beep puternic) se poate face foarte usor parcurgand urmatorii pasi:
In fereastra DEVICE MANAGER, meniul VIEW se desfasoara oferind optiunea SHOW HIDDEN DEVICES.
In lista de periferice va fi afisat "BEEP". Apasati cu butonul dreapta al mouse-ului pentru afisarea meniului contextual. In acest meniu, selectati optiunea DISABLE.

73 de yo3hjv

01 septembrie 2007


you can find a solution for a "military-like" backpack radio based on FT857D.

TIP for mobile useres:
Two male RJ11 and 3m of 6 wire telephone cable for front panel, one male and one female RJ45 and 3m of 8 wire FTP cable for microphone.
The main issue is how to find a proper receptacle for the front panel... Well, this rceptacle is right on the radio, and is fixed on 4 screws. It's part number on the service manual is RA0450600 as shown on the picture below:

You can unscrew that receptacle and used it with some PDA support to attach it on the windshield with a suction cup. I use the same solution with my FT 8900...
It is the best solution for who is interested in a permanent mobile solution. Why spend a lot of $$$ on a "mobile separation kit"???

73! de yo3hjv

Compact, full featured, modern look

Crammed into the little enclosure is an 100kHz-500MHz transceiver (receiving. Transmitting is subject to ham band limitations) with most of the modern bells and whistles that anyone could want, and which can supply 100 watts on 160-6 meters, 50 watts on 2 meters, and 20 watts on the 440 MHz band.
Is operating in the CW, AM, SSB, FM, and digital modes.
The main purpose of this radio is to be installed as a mobile rig, with removable front plate which can be mounted away from the main unit.
The single limitation of this kind of installation is the microphone and the speaker, which are connected directly to the main unit thus a second cable will be necessary.

I purchase this radio in the spring of 2006 from WIMO, a reseller located in Germany. I was, somehow, budget-orientated. My HSU (Ham Speding Units) was around 650 EUR and this radio fits very well (620EUR+shipping 36EUR) so I ordered right away!
I was very happy to have a "all band-all mode HF+VHF+UHF transceiver in one box. Furthermore, I needed a radio which could be the basis for a very portable station for field use. The FT-857 fills both requirements nicely.

The first approach to this radio was to download a pdf user manual (operationg manual) to see the features and to imagine what I can do with it. This is a habit to me in order to be already familiar with a new radio because I am a real ham and real hams do not read the manual when a radio is sitting in front!

The first thing I did when the radio arrived was to look inside...
I liked the solid aluminium frame in the central section and how the circuit boards are fitted! A solid frame is the key for a good thermal behavior and also a good backbone for a mobile or portable radio.
The FT-857 is build to last and to survive a lot of mechanical abuse.

The top circuit board contains all of the low level electronics. Although there is no space left over, nothing seems crammed into the space at all.
I saw a lot of radios from inside. Also I was a constructor of radios and other electronic things... It's like a classic painting what the Yaesu engineers manage to do in this box! Nevertheless, their work has made a design which is logical, clean, easy to repair and should be very reliable.

The bottom circuit board contains the separate HF and VHF/UHF power amplifiers, and all of the band switching components. Once again, the board looks full but very logical, with a very clean layout. The heat from the power transistors is coupled directly to the main casting, and the twin fans provide the air movement necessary to extract the heat from the unit. The fans run only when necessary, with variable speed, so the unit is quiet most of the time.

I purchase an optional original Yaesu SSB filter but on receiving it isn't what I expected! But in Tx-ing reports are better than the built-in ceramic filter, so i will keep it.
The pictur shows the two optional filters.

I like

This radio is tiny and modular. The removable faceplate is a good thing for mobile installation and even for a crowded ham shack.
If space is principal consideration, then the FT-857D is the best all=mode all-band full-power space-saver currently available.
The price also is good! Do not expect to have performances like a Kenwood TS2000! It is a very good radio in it's price range!

Reasonable front panel – With small size comes along the necessity to cram the front panel functionality into a minimum of controls. Reading the manual is absolutely required in order to get the maximum functionality out of the FT-857. However, the controls are well-thought-out, and benefit from a couple of generations of small equipment with few controls. The function selection and the menus allow everything to be controlled, and they have obviously thought through the usability of these. After a few weeks of trying every feature, I can go directly to what I need without referring to the manuals any more. For anything this complex, that is high praise.

Receive audio is quite good – The primary limitation on receive audio is the tiny speaker in the case. For any real use, it cries out for an external speaker. I have plugged in high-quality external speakers, and the audio is as good. There is also plenty of audio power available. Driving an inefficient old acoustic suspension speaker is no problem at all. Furthermore, there is a headphone jack on the front left side of the FT-857, which makes headphone use an easy thing. They provide a switch to change the power level on the headphone jack so that if you should want to power a larger speaker from that jack, the FT-857 will drive it. This is very well thought-out.

External programming software – After I bought the radio, I also bought the ADMS-4B programming software. The programming cable I made it myself with just two bipolar transistors and some passive components. Also I like how interacts with the Ham Radio Deluxe CAT, but the credits goes to the authors of the software!

DSP - Is OK for a audio only DSP and performs well on a crowd band. Also useful with the QRM and best on static noises.

All band coverage, including the CB which is very usefull on the road! Unfotunately, I was not able to make a good installation on my new car...

Adjustable drag on Dial Knob. No more to say about! Not to many hams are aware about this feature!

I don't like

No direct frequency entry - Unless you buy the fancy external microphone, it is not possible to do direct frequency entry. I can solve this with one easy purchase, but I already know how difficult can be as I have a ICOM IC2100 with a remote mic. Not so bad, but sometime I miss this feature.
No built-in tuner – I solved this with an external LDG AT-11MP and later a Z100 also from LDG (in portable operations) which matches the size of the radio, and will load up nearly anything. I read a lot of reviews for Yaesu tuners and I don't want to buy one! I also miss a OTT (One Touch Tuning) switch on the front panel! Could be useful a single switch to put a CW, 5W for external ATU.

Unlabeled back panel – There is a sticker on the bottom of the radio showing which of the many back panel connectors do what, but I miss having the labels where I can see them. I used a permanent ink pen to make my own "labels".

A connector or a hole or whatever to ground the radio direct to the chassis. I really miss this because I like to have a well grounded shack! I drive a hole through the rear aluminium solid block to connect a wire for grounding... Grrrr...

The SELECTOR knob is very poor! Is some optical switch with a high failure rate! Mine is fail to switch in the needed direction. Forward-back-forward when switching only forward or backward...

So that is it. I consider the FT-857 to be a really good deal in a ham radio transceiver, and one which is well-suited to anyone needing one which will fit into a very small space or need a second radio for field day, portable or DX-speditions. I really like my Kenwood TS-2000X "Big Rig" with all of the controls up-front, but the FT-857 does very well within the small space it requires.

In the spring of 2007 I sold the radio to purchase a Kenwood TS2000X. After the radio "travelled" from ham to ham, I bought it back in order to go in Elba Island, portable. So, Is here to stay... or to go portable again!

73! de YO3HJV

Here is the specifications from Universal Radio.com:

Frequency Range: Receive:
0.1-56, 76-108, 118-164 and 420-470 MHz
160 - 6 Meters including 60 Meters
2 Meters
70 Centimeters (Amateur bands only)
5167.5 kHz: Alaska Emergency Frequency
(U.S.A. version only)
Emission Modes:
A1 (CW), A3 (AM), A3J (LSB/USB),
F1 (9600 bps Packet), F2 (1200 bps Packet), F3 (FM)
Synthesizer Steps (Min.):
10 Hz (CW/SSB), 100 Hz (AM),
100 Hz (FM), 100 Hz (WFM)
Antenna Impedance:
50 Ohm, Unbalanced
Operating Temp. Range:
-10 °C to +60 °C (14 F to 140 F)
Frequency Stability:
Better than ±4 ppm (-10 °C to +50 °C)

Power Requirements:
DC 13.8V ±10 %, Negative Ground
Current Consumption:
Receive (Squelched) : 0.55A,
Receive (Max. Audio) : 1A
Transmit : 22A (@ 100W RF output)
Case Size:
6.1" (W) x 2.0" (H) x 9.2" (D) (155 x 52 x 233 mm)
4.6 lb. (2.1 kg.)
Power Output:
160 - 6m : 100 Watts (25 Watts AM carrier)
2m : 50 Watts (12.5 Watts AM carrier)
70cm : 20 Watts (5 Watts AM carrier)
Modulation Types : SSB:
Balanced Modulator
Variable Reactance
Early Stage (Low Level)
FM Maximum Deviation:
±5 kHz (±2.5 kHz on FM-N)
Spurious Radiation : Harmonics:
At least 50 dB down (1.8 - 29.7 MHz)
At least 60 dB down (50/144/430 MHz)
At least 50 dB down (1.8 - 29.7 MHz)
At least 60 dB down (50/144/430 MHz)
Carrier Suppression:
At least 40 dB
Opp. Sideband Suppression:
At least 50 dB
SSB Frequency Response:
400 Hz - 2600 Hz (-6 dB)
Microphone Impedance:
200 - 10 k Ohm (Supplied microphone: 2 k Ohm)

100 kHz - 1.8 MHz (IPO off):
- uV 32 uV -
1.8 - 28 MHz:
0.25 uV 2 uV -
28 - 30 MHz:
0.2 uV 2 uV 0.50 uV
50 - 54 MHz:
0.125 uV 1 uV 0.2 uV
144/430 MHz:
0.125 uV - 0.2 uV
SSB/CW/AM-N figures are for 10 dB S/N, 12 dB SINAD on FM

Squelch Sensitivity : SSB/CW/AM FM
1.8 - 28 MHz : 2.5 uV -
28 - 30 MHz : 2.5 uV 0.32 uV
50 - 54 MHz : 1 uV 0.16 uV
144/430 MHz : 0.5 uV 0.16 uV

Intermediate Frequencies : 0
1st IF : 68.33 MHz (SSB/CW/FM/AM)
0 10.7 MHz (W-FM)
2nd IF : 455 kHz
Image Rejection : Better than 70 dB (1.8 - 30 MHz, 50 - 54 MHz)
00 Better than 60 dB (144 - 148 MHz, 430 - 450 MHz)
IF Rejection : Better than 60 dB
Selectivity (-6 / -60 dB) : 0
SSB/CW : 2.2 kHz/4.5 kHz
CW : 500 Hz/2.0 kHz (Optional YF-122C installed)
CW-N : 300 Hz/1.0 kHz (OptionalYF-122CN installed)
AM : 6 kHz/20 kHz
FM : 15 kHz /30 kHz (-6 / -50 dB)
Audio Output : 2.5 W into 4 Ohm @ 10% THD
Audio Output Impedance : 4 Ohm - 16 Ohm

31 august 2007

Alinco DJ-580

I owned one of this portables in the mid of 90's.
Was bought from a flea market for around 500 bucks... A enormous price, but... I did want it!
The radio was a little too bulky as I have a TH-79 to compare. Also, the menu was a little bit confusing for my brain.
The sensitivity was poor and the selectivity was the same. I repeat, in comparation with the Kenwood dual bander TH-79.
I remember that I had have to make some hardware modifications in order to achieve full duplex operation.
The transmitter was the same as the receiving. Poor.
But you have to consider that I used the stock antenna and, at that time, I didn't know that stock antennas performed generally bad.
The great thing was the dual band receive.
Generally speaking, I think that the DJ-580 was a replica to the well-built Yaesu FT-530.
If asked, I will not buy again!


26 august 2007

Antena multiband HF pentru portabil

Am reusit sa finalizez articolul referitor la realizarea unei antene pentru lucrul din portabil, multiband HF.
In urma testelor a rezultat ca antena poate fi instalata in maxim 15 minute si acopera foarte bine benzile HF de la 80-10m, inclusiv benzile WARC.

Costul de "productie" al antenei este de maxim 60 de lei, iar ansamblarea are loc in cateva ore.
Raman la parerea mea, ca antena merita construita! Mai bine cumpar un antenna tuner automat cu care pot sa acordez diverse antene. In fond si la urma urmei, radioamatorismul inseamna si ceva constructie, cred eu!

Voi posta in continuare textul articolului, cei care doresc sa studieze si imaginile luate in timpul executarii antenei, pot descarca varianta in format pdf.

Antena verticala HF.

Acum aproximativ 10 ani, foloseam din plin banda CB. Era ceva mai “linistita” decat azi iar utilizatorii mai cu bun simt. In acea perioada, o antena “de fabrica” costa destul de mult si era relativ greu de procurat, astfel incat am incercat sa realizez una din materiale “domestice”. Intrucat experienta a fost reusita iar antena rezultata a functionat mai bine de 6 ani pe terasa unui bloc (in ultimii doi ani chiar am utilizat-o cu succes in gama 6-80m cu ajutorul unui Antenna Tuner marca LDG, model AT11MP), am hotarat sa repet experienta, de data aceasta cu unele imbunatatiri si renuntand la banda de 80 de metri.

Scopul initial, dupa cum am aratat mai sus, a fost obtinerea unei antene verticale fiabile, cu rezultate relativ bune si cu costuri cat mai scazute intr-un timp de ordinul orelor.

Antena verticala prezinta o serie de avantaje, incepand cu unghiul de radiatie care o face atractiva pentru DX si terminand cu spatiul redus necesar pentru instalare.

Antena urma sa fie de tip “center loaded”, adica cu bobina la mijloc pentru a mai reduce impedanta la punctul de conectare.

Principalele “ingrediente” pentru aceasta antena sunt:

- Undita de fibra de sticla (probabil ca merge si fibra carbon) de 7 m.

-15 m de cablu electric Cu multifilar torsadat izolat cu PVC si cu sectiune de 2-4 mm;

- Teava de instalatie electrica cu diametrul de 18-20mm, aproximativ 20 cm;

- Un umeras din sarma otelita de aproximativ 1,5 mm diametru;

- Coliere pentru prinderea furtunului de admisie de aer al carburatorului de Dacie;

- Superglue sau glue termic;

- Tub eletroziolant termoconstrictor;

- Banda izolatoare semielastica;

- Sarma Cu izolata, monofilara, diametru 1,5mm, aproximativ 50 cm;

- 3 clestisori pentru fir electric;

- 1 m de cablu coaxial de tip RG 58.

Costul total al materialelor este de aproximativ 60 de lei, cu mici variatii in functie de suma platita pe undita (aproximativ 20-25 lei).

In primul rand, vom taia din tubul de PVC pentru instalatie electrica doua segmente de aproximativ 10 cm. Pe acestea le vom gauri strapuns pe o generatoare a cilindrului rezultat, cu un burghiu de aproximativ 4mm, la distanta de aproximativ 5 mm de capete.

Vom realiza doua bobine, una cu fir izolat multifilar, cea de a doua cu fir monofilar, pastrand izolatia originala.

Prima bobina, realizata cu firul multifilar, are pas variabil, in sensul ca incepe cu spira langa spira, marind treptat pasul infasurarii. Vom obtine astfel aproximativ 25spire. Numarul de spire nu este critic intrucat antena pe care dorim sa o realizam va fi folosita cu un tuner. Scopul acestei bobine este de a realiza o lungire artificiala a elementului radiant. Bobina urmeaza sa fie amplasata la jumatatea antenei, in interiorul unuia dintre segmentele telescopice ale unditei.

Desfacem undita telescopica si extragem prin capatul de jos (spre maner) sectiunea cea mai subtire a unditei. De cele mai multe ori, in cazul unditelor din fibra de sticla, aceasta sectiune este si ea goala pe interior pana la capat, unde diametrul intern are aproximativ 1 mm.

Taiem o bucata de aproximativ 30 de cm din sarma otelita a umerasului si o indreptam. Apoi, cu ajutorul unei pile si a unui decapant bun (eventual incercati cu o aspirina daca alta solutie nu da rezultate) cositorim acel capat.

Celalalt capat il pilim astfel incat sa nu prezinte bavuri.

Desizolam o mica bucata din firul multifilar de Cu si o lipim pe sarma otelita apoi punem o bucata de aproximativ 3 cm de tub termoconstrictor peste lipitura.

Introducem cu atentie sarma in segmentul unditei si imobilizam, fie cu putin superglue (totusi e casant!) fie cu ajutorul unui pistol cu clei termic.

Taiem cablul de Cu multifilar la aproximativ 4 m de la varf (aceasta masuratoare include si segmentul de fir otelit introdus in segmentul cel mai mic al unditei).

Scoatem pe rand inca trei segmente din undita, in ordinea grosimii, astfel incat sa putem ansambla deja jumatatea superioara a unditei, trecand firul prin interior. Cel mai probabil ca bobina cu pas variabil va incapea lejer in segmentul cel mai propiat de cei 3,5m necesari pentru partea superioara a elementului radiant.

Realizam o conexiune solida din punct de vedere electric dar si mecanic a firului cu bobina si o introducem in tub.

Bobina va avea spirele cu pasul mai mare catre manerul unditei, implicit pasul mai des spre varf.

Pe modelul de undita folosit de mine, 3,5 m de radiant inseamna ca la extinderea unditei, bobina se gaseste complet incorporata intr-un segment.

La al doilea capat al bobinei realizam o legatura similara pentru alta bucata de fir.

Ansamblam in totalitate undita pentru a stabili repere pe cablul care coboara catre maner si apoi taiem, cu o rezerva de aproximativ 20 cm.

A doua bobina, realizata tot pe tub PVC pentru instalatie electrica are rolul de a descarca in curent continuu antena, protejan astfel transceiverul la descarcari electrostatice, mai ales cand aneta este amplasata pe bloc. Dezavantajul major este ca reduce randamentul la frecvente scazute, facand operarea in banda de 80 de m aproape imposibila.

Bobina se realizeaza din fir solid de Cu pentru a suporta eventualele traznete care ar putea lovi antena.

Fac o paranteza: Vechea antena pe care am inlocuit-o avea o astfel de gaura in materialul unditei, probabil de la un brat secundar al unui traznet. Din fericire bobina de descarcare a suportat descarcarea desi a iesit cam afumata!

Aceasta bobina va avea si ea tot aprozimativ 25 spire. O solutie ar fi inlocuirea acestei bobine cu un tub de descarcare in gaz, special destinat descarcarii statice. Alta solutie ar fi inlocuirea cu o bobina realizata pe un tor de ferita, cu impedanta foarte mare.

In fine, scopul acestui articol nu este sa trateze matematic si stiintific antena verticala si elementele sale de acord ci doar sa ofere o alternativa rapida si necostisitoare la antenele de fabrica.

Deci, revenim la cea de-a doua bobina: La un capat conectam firul care vine dinspre varful unditei si firul cald al cablului coaxial iar in celalalt capat realizam un cerc ( sau orice forma care sa permita agatarea clestisorilor) din aceeasi sarma folosita la bobinaj si conectam tresa cablului coaxial.

Antena se instaleaza fie pe un stalp fie pe un tarus metalic sau din material izolant, pe sol, cu ajutorul celor doua coliere de carburator. Este bine ca la instalare, sa infasuram manerul unditei intr-o bucata de cauciuc recuperat de la o camera auto pentru a evita spargerea fibrei de sticla.

Si mai bine ar fi daca am glisa peste maner o bucata izolator termic pentru instalatiile de aer conditionat. Este un material spongios care serveste foarte bine acestui scop.

Verticala functioneaza optim daca utilizam si trei “contragreutati” de lungime aleatoare (intre 1 si 2 metri) realizate din restul de sarma de Cu multifilar.

Antena este gata pentru a fi folosita, dar, mare grija, folositi si un tuner!

Prima astfel de antena nu a avut bobina la mijloc iar lungimea efectiva a elementului radiant era de aproximativ 5,7m intrucat ultimul segment al unditei era plin si a trebuit sa il elimin din constructie. In 6 ani de utilizare am avut placerea de a lucra statii din Europa, America de Sud si Africa. Segmentele au fost lipite in pozitie cu superglue ceea ce a facut ca antena sa nu mai poata fi pliata.

A doua antena construita pe acelasi principiu are acum 7 metri “full” si bobina in interior.

Intentionez sa mai realizez o antena asemanatoare pentru a o utiliza in regim portabil.

Problema majora in cazul antenelor verticale o constituie rezistenta mecanica la factorii de mediu iar undita este un element mecanic proiectat sa suporte sarcini mari ceea ce o face deosebit de atractiva. Radiantul poate fi, fie trecut pe exteriorul antenei – ceea ce face antena sa devina fragila la sarcini mecanice pe directia firului radiant, fie prin interior –ceea ce o face sa raspunda uniform la sarcini generate de vanturi, indiferent de directia pe care acestea actioneaza.

Totodata, greutatea unei undite, fie ea si cu un fir si o bobina in interior este cu mult mai mica decat greutatea unei antene la lungime similara realizata din aluminiu sau alte materiale.

Inca nu stiu ce nume sa ii dau acestei antene! Probabil ca va fi un acronim de genul: AVMHFPRI, adica Antena Verticala Multiband HF Pentru Radioamatorii cu Idei… J Este un punct de plecare pentru o constructie pe care o puteti imbunatati.

Cel mai important aspect al ei este ca va ofera o satisfactie la sfarsitul a maxim 2 ore de munca plus inca o ora pentru adunatul materialelor, alta ora pentru instalarea pe bloc si maxim 100 de lei cheltuiti! Tocmai buna pentru o duminica ploioasa, nu credeti?

Sper ca aceste randuri sa va faca sa redescoperiti pasiunea de a construi.

Adrian Florescu


24 august 2007

My radio shack

Today I decided to put some pictures and some descriptions of my equipments on this site.
Because of limited space here, I made a custom-designed furniture. From the room, it looks like a bookcase but from lateral is my radio shack...
So, here are the pictures:
1-IBM Thinkpad T43 for home operation. For Portable I use a smaller one, without optical unit, just the minimum needs: X40. Both have extended battery for a minimum 4 hours usage;
2-ALINCO DM 330 MVE switching power supply with a 12V/12A SLA back-up battery; Yaesu MD-1ooDesktop microphone modified to work with Kenwood radios.
3-Main radio unit: Kenwood TS2000X with a 2m/70cm diplexer on the upper side. The diplexer is visible on the last picture (Hi res);
4-Secondary radio unit: Yaesu FT857D. Two ATU: AT11-MP (for Kenwood radio and a smaller Z100 for Yaesu FT857D. For 2m, a dedicated Icom IC2100H (with a dipole antenna at my window. I live at 8'th floor!). In the left side of this unit, is a small Frequency counter housed in a pager case. This is very useful to capture what's on air in proximity...
5-Home made 1.5Ghz frequency counter;
6-Various devices. A Graupner Ultramat 25 multirole battery charger-maintainer-analyzer unit (very useful for charging portable batteries).
7-10 various portable radios: Alinco DJ-G5, Yaesu VX-150, Motorola GP300, Kenwood TH-F7 and Vertex VX-10 UHF,

I have 3 cables up to the roof (pictures coming soon) for a x-5000 triband antenna, a vertical home made HF multiband (from a fishpole stick) and one is left for future development (HI).
Also, like I said, I have a vertical dipole on my window just for 2m local QSO. "Local" means that I can open repeaters about 130km away...

For VHF/UHF I used Heliax cable and for HF LMR.
The three cables are routed behind the radios, inside the furniture, except the window-dipole which is routed by a pipe through the wall.

I do not make my own radios because I do not have so much time and patience but I like to eperiment with antennas!

Software I use for ham "business":

-Ham radio Deluxe;

I plan to use a RigExpert Standard USB interface (I wait the shipment) for digital modes. Now I use a home made... hm... interface (just plain wires and connectors) in order to make some order here!

You can call me on 20m band in PSk31, Olivia, AMTOR and other digital modes...

So... this is my shack!


RFSM-2400 Digital mode

The following article is in romanian language as I intend to make it accesible to romanian hams. The original documentation about this digimode can be found on the internet, especially on this page.

Din curiozitate si dintr-o usoara plictiseala legata de eternul SSB in benzile de unde scurte, am inceput sa "sap" pe internet dupa tot felul de moduri digitale
Am ajuns la acest obiectiv dupa ce am citit un material despre experienta unui radioamator in urma dezastrului de la WTC din 11 septembrie 2001, cand reteaua de urgenta ARES a radioamatorilor americani a intrat in functiune.
Una din problemele ridicate de reteaua de urgenta a fost transmiterea de liste cu necesarul de materiale si cu beneficiarii acestora.

Solutia gasita de radioamatori a fost utilizarea de moduri digitale care sa permita transmisia cu cat mai putine erori a datelor, date care sa poata fi integrate automat in diferite sisteme de evidenta. Ma rog, daca nu automat, atunci macar sa poata fi copiate in alte programe fara sa fie nevoie sa fie rescrise de mana. Pe scurt, o solutie sigura care sa consume cat mai putin timp din partea operatorului.
Acestui deziderat ii raspunde cel mai bine radio-pachetul, care permite transmisia la o viteza relativ ridicata de 1200 baud.
Totusi, viteza propusa este atinsa in retelele constituite pe UUS, in a
numite conditii. Pentru retelele HF, viteza la care se poate spera este de aproximativ 300-400 baud. Transmisia unui fisier tip document tabelar (aprox. 30Kb) ar dura extrem de mult in aceste conditii. Ma refer la transmisia pe unde scurte.
Alte solutii derivate din TTY pot satisface cerinta transmisiei de text dar nu sunt la fel de bine protejate impotriva erorilor, putand genera incurcaturi in mediul specific generat de un eveniment de natura sa mobilizeze o retea de urgenta.

Tot cautand, am gasit ceva informatii despre un nou mod digital propus de radioamatorii din Rusia si Finlanda.
Este vorba de un mod digital, capabil sa transmita la o viteza superioara, in jurul valorii de 3000bps in benzile de unde scurte, cu algoritmi de corectie a erorilor.
Acest mod de lucru a fost dezvoltat plecand de la standardul militar MIL-STD-188-110A.
Programul se numeste RFSM-2400, acronim de la Radio Frequency Software Modem si poate fi descarcat de aici.

Programul se prezinta sub forma unei arhive zip. Il descarcati si il dezarhivati ca atare, el creind un folder denumit RFSM ce contine toate fisierele necesare rularii

Autorii programului recomanda o configuratie destul de “puternica” pentru calculator:

- Procesor: Pentium-III 600 / Athlon 600 sau peste.
- RAM: Minim 32Mb (presupun ca acestia sunt cei ramasi liberi in afara resurselor cerute de sistemul de operare).

- Video: minim VGA 640x480
- Placa sunet, DirectX-compatible, 44100 Hz sau 48000 Hz.
- OS: Windows 95/98/ME/2K/XP/2003 (with DirectX 5.0+) or Linux (with WINE).
- COM-port (pentru controlul PTT). Nu este neaparat necesar, putandu-se folosi functia VOX a TRX-ului.

Programul permite urmatoarele actiuni:

-chat intre statiile conectate;

-transfer de fisiere la 2400baud;

-acces internet;

-transfer de mesaje e-mail.

Iata si cateva din caracteristicile lui:

- utilizeaza modulatia definita de MIL-STD-188-110A (inclusiv versiunile modificate).
- viteza maxima de transfer: 3200 bps (standard) and 2666 bps (non-standard).
- banda de frecventa ocupata: 0,3-3,3 kHz (standard) si 0,3-2,7 kHz (non-standard).
- sistem adaptiv de corectie..
- foloseste optimizare SSE2 (depinde de disponibilitatea procesorului)
- poate utiliza portul COM pentru controlul TRX.
- permite corectia erorilor generate de placa de sunet.
- transferul de fisiere utilizeaza tehnica ARQ (Repetarea blocului d
e date compromis)
- baze de date simplificate pentru statiile corespondente si pentru monitorizarea pachetelor.

Personal, am creat in radacina C:/ un folder denumite Digimodes, cu subfolder pentru fiecare program instalat. In felul acesta este mai usor sa le gasesc atunci cand doresc sa accesez diferitele fisiere log necesare pentru “reglaje”.

Pentru a porni programul, cautam in folderul RFSM rezultat in urma dezarhivarii fisierul RFSM2400.exe. Dublu click pe fisier sau cream un shortcut pe desktop pentru acces mai facil.

Odata lansat programul, pe ecran vom avea fereastra principala a acestuia:

Din cate am observat, programul utilizeaza rutinele DirectX ale Windows-ului. Mesajul “Wait connection” semnifica starea de asteptare a unui semnal care sa fie decodificat.

Bara de pictograme este dublata de meniului tip Text din partea superioara a ferestrei de program.

Primul pas pe care vi-l recomand este sa accesati meniului Options>Preferences sau direct pe pictograma cu unelte, unde vom seta cativa parametri necesari unei functionari corecte.

Este important sa retineti ca programul face distinctie intre caracterele minuscule si caractere majuscule ale indicativelor! Astfel, YO3HJV este diferit de yo3hjv si o conexiune care are ca destinatar o statie al carei indicativ este definit cu majuscule va trebui solicitata tot cu majuscule. Conventional s-a ales utilizarea majusculelor.

Al doilea pas, foarte important, este setarea placii de sunet. Acestea sunt accesibile pe tablita “Hardware” a meniului :

Optiunile “DirectSound devices” si “WaveIn devices” se refera la utilizarea resurselor software (DirectX) si, respectiv, hardware, ale calculatorului in tratarea sunetului. Eu am utilizat cu succes resursa hardware intrucat dispun de mai multe placi de sunet atasate pe USB la calculator si am alocat direct resursa hardware.

Sub aceste optiuni, se observa meniul de setare a frecventei de esantionare a placii alese, atat la receptie cat si la emisie. Programul poate utiliza placi audio cu doua frecvente de esantionare: 48kHz si 44,1kHz. Placa aleasa esantioneaza la 44,1kHz, asadar am ales aceasta varianta. Meniul “Rx Real…” si “Tx real…” sunt utilizate pentru a calibra cat mai exact placa de sunet in scopul atingeri performantei maxime la rata de transfer. Eu nu am realizat aceasta calibrare.

Pentru posesorii de calculatoare cu procesor multimedia sau mai bun, exista optiunea de a bifa utilizarea de algoritmi SSE2. Utilizarea lor degreveaza procesorul de o serie de sarcini suplimentare.

Dupa ce am efectuat aceste setari, este nevoie sa alegem modul de lucru. Acesta este disponibil pe tablita “Modulation”:

Modurile de lucru disponibile sunt:

-Mil … standard, banda audio extinsa, astfel cum este definita prin standard;

-Non-standard, banda audio restransa;

-Dumb modem, mod de lucru in care este exclusa interventia utilizatorului (utila pentru functia de nod retranslator), posibila doar impreuna cu modul Non standard.

In acest meniu de configurare mai avem tablite pentru controlul modului in care este actionat PTT-ul statiei, culorile mesajelor etc. Nu insist asupra acestor setari intrucat nu sunt esentiale pentru exploatarea programului ci constituie elemente de personalizare a interfetei grafice.

Odata ce am efectuat aceste setari, putem inchide acest meniu, incepand utilizarea propriu zisa a programului.

Conectarea cu transceiver-ul se realizeaza prin intermediul unei interfete intre placa de sunet a calculatorului si TRX. Personal am folosit o conexiune directa, fara transformatoare si fara element de comanda derivat din COM, exploatand facilitatea VOX existenta pe transceiver. Intrucat acest mod de conectare l-am verificat cu alte moduri digitale iar semnalele sunt curate, fara semnale parazite sau brum, nu am gasit motiv sa renunt la el.

Nu intru in detalii privind aceasta conectare intrucat ea difera de la TRX la TRX. Pot insa sa va recomand sa elimineati orice filtre si egalizatoare pe traseul audio, sa setati constanta de timp a circuitului AGC cat mai scurta (la receptie) si sa nu supramodulati.

Frecventele utilizate pentru acest mod sunt, in principiu, cele utilizate pentru retele bazate pe ALE (Automatic Link Establishment) si sunt actualizate periodic pe pagina www.hflink.com.

In marea majoritate a timpului, statia mea este in QRX pe 14,10950 Mhz.

Voi mai completa acest material cu noi informatii despre "peripetiile" cu RFSM2400.



10 august 2007

How to sound like a LID on local repeaters

How to sound like a LID

Step One: Use as many "Q" signals as possible. Yes, I know they were invented solely for CW and are totally inappropriate for FM, but they are fun and entertaining. They keep people guessing as to what you really meant. I.E. "I'm going to QSY to the phone." Can you really change frequencies to the phone? QSL used to mean, "I am acknowledging receipt", but now it appears to mean, "yes" or "OK". I guess I missed it when the ARRL changed the meaning. It is also best to use "OK" and "QSL" together. Redundnat redundancy is the better part of Lid-dom.

Step Two: Never laugh when you can say "HI HI". No one will ever know you aren't a long time CW rag-chewer if you don't tell them. They'll think you've been on since the days of Marconi.

Step Three: Utilize an alternative vocabulary. Use words like "destinated" and "negatory". It's OK to make up your own words here. I.E. "Yeah Tom, I "pheelbart zaphonix" occasionally myself."

Step Four: Always say "XX4XXX" (Insert your own call) "for I.D." As mentioned in Step One, anything that creates redundancy is always encouraged. That's why we have the Department of Redundancy Department. (Please note that you can follow your call with "for identification purposes" instead of "for I.D." While taking longer to say, it is worth more "LID points".

Step Five: The better the copy on two meter FM, the more you should use phonetics. Names should be especially used if they are short or common ones. I.E. "My name is Al... Alpha Lima" or "Jack.. Juliet Alpha Charlie Kilo." If at all possible use the less common HF phonetics "A4SM... America, Number Four, Sugar Mexico." And for maximum "LID points", make up unintelligible phonetics. "My name is Bob... Billibong Oregano Bumperpool."

Step Six: Always give the calls of yourself and everyone who is (or has been) in the group, whether they are still there or not. While this has been unnecessary for years, it is still a great memory test. You may also use "and the group" if you are an "old timer" or just have a bad memory. Extra points for saying everyone's call and then clearing in a silly way - like "Tthis is K2xxx, Chow, Chow."

Step Seven: Whenever possible, use the wrong terminology. It keeps people guessing. Use "modulation" when you mean "deviation", and vice-versa. And even if the two-meter FM amplifier you're using is a Class C type amp, and thus not biased for linear amplification, be sure to call it your "linear." Heck, refer to all FM-style amplifiers as "linears." You'll be king of the "wrong terminology" hill.

Step Eight: If someone asks for a break, always finish your turn, taking as long as possible before turning it over. Whenever possible, pass it around a few times first. This will discourage the breaker, and if it is an emergency, encourage him to switch to another repeater and not bother you.

Step Nine: Always ask involved questions of the person who is trying to sign out. Never let him get by with just a "yes" or "no" answer. Make it a question that will take him a long time to answer.

Step Ten: The less you know on a subject, the more you should speculate about it in the roundtable. Also the amount of time you spend on the subject should be inversely proportionate to your knowledge of the subject even though you have no damn clue.

Step Eleven: Always make sure you try to communicate with only a handheld and a rubber duck antenna. Also, make sure you work through a repeater that you can hear very well, but it cannot hear you. This will put out a kind of "LID mating call": "Well, Joe, I can hear the repeater just fine here. I wonder why it can't hear me?" You will score maximum LID points if you are mobile, and with the radio lying in the passenger seat.

Step Twelve: If you hear two amateurs start a conversation, wait until they are twenty seconds into their contact, and then break in to make a call, or better yet to use the auto-patch. Make sure you keep the repeater tied up for at least three minutes. This way, once the two have re-established contact, they won't even remember what they were talking about.

Step Thirteen: You hear someone on the repeater giving directions to a visiting amateur. Even if the directions are good, make sure you break in with your own "alternate route but better way to get there" version. This is most effective with several other "would-be LIDs", each giving a different route. By the time the visiting amateur unscrambles all the street names whizzing by in his mind, he should have moved out of the range of the repeater. This keeps you from having to stick around to help the guy get back out of town, later.

Step Fourteen: If an annoying station is bothering you, make sure your other "LID" buddies have a "coded" frequency list. Even though "CODES" are strictly forbidden on Amateur Radio, it's really neat to practice "James Bond" tactics.

Step Fifteen: Always use the National Calling Frequency for general conversations. The more uninteresting, the longer you should use it. Extra points are awarded if you have recently move from an adjacent frequency for no reason. Make sure when DX is "rolling" in on 52.525 that you hang out there and talk to your friends five miles down the road about the good old CB days!

Step Sixteen: Make sure that if you have a personal problem with someone, you should voice your opinion in a public forum, especially a net. Make sure you give their name, call, and any other identifying remarks. For maximum points, make sure the person in question is not on the repeater, or not available.

Step Seventeen: Make sure you say the first few words of each transmission twice, especially if it is the same thing each time. Like "roger, roger" or "fine business, fine business". I cannot stress enough about encouraging redundancy.

Step Eighteen: If you hear a conversation on a local repeater, break in and ask how each station is receiving you. Of course they will only see the signal of the repeater you are using, but it's that magic moment when you can find a fellow "LID", and get the report. Extra points are awarded if you are using a base station, and the repeater is less than twenty-five air miles from you.

Step Nineteen: Use the repeater for an hour or two at a time, preventing others from using it. Better yet, do it on a daily basis. Your quest is to make people so sick of hearing your voice every time they turn on their radio, they'll move to another frequency. This way you'll lighten the load on the repeater, leaving even more time for you to talk on it.

Step Twenty: See just how much flutter you can generate by operating at handheld power levels too far away from the repeater. Engage people in conversations when you know they wont be able to copy half of what your saying. Even when they say your uncopyable, continue to string them along by making further transmissions. See just how frustrated you can make the other amateur before he finally signs off in disgust.

Step Twenty One: Use lots of radio jargon. After all, it makes you feel important using words ordinary people don't say. Who cares if it makes you sound like you just fell off Channel 19 on the citizen's Band? Use phrases such as "Roger on that", "10-4", "I'm on the side", "Your making the trip" and "Negatory on that".

Step Twenty Two: Use excessive microphone gain. See just how loud you can make your audio. Make sure the audio gain is so high that other amateurs can hear any bugs crawling on your floor. If mobile, make sure the wind noise is loud enough that others have to strain to pick your words out from all the racket.

Step Twenty Three: Start every transmission with the word "Roger" or "QSL". Sure, you don't need to acknowledge that you received the other transmission in full. After all, you would simply ask for a repeat if you missed something. But consider it your gift to the other amateur to give him solace every few seconds that his transmissions are being received.

Step Twenty Four: When looking for a contact on a repeater, always say your "listening" or "monitoring" multiple times. I've always found that at least a half dozen times or so is good. Repeating your multiple "listening" ID's every 10 to 15 seconds is even better. Those people who didn't want to talk to you will eventually call you, hoping you'll go away after you have finally made a contact.

Step Twenty Five: Always use a repeater, even if you can work the other station easily on simplex ... especially if you can make the contact on simplex. The coverage of the repeater you use should be inversely proportional to your distance from the other station.

Step Twenty Six: When on repeaters using courtesy tones, you should always say "over". Courtesy tones are designed to let everyone know when you have unkeyed but don't let that stop you. Say "over", "back to you" or "go ahead". It serves no useful purpose but don't worry, it's still fun!

Step Twenty Seven: Use the repeater's autopatch for frivolous routine calls... especially during morning or evening commute times. While pulling into the neighborhood, call home to let them know you'll be there in two minutes.... or, call your spouse to complain about the bad day you had at work. After all, the club has "measured rate" service on their phone line so they get charged for each autopatch call. Your endeavor is to make so many patches in a year that you cost the club at least $20 in phone bills. That way you'll feel you got your money's worth for your dues!

Step Twenty Eight: Never say "My name is ....." It makes you sound human. If at all possible, use one of the following phrases: a) "The personal here is ..." b) "The handle here is..."

Step Twenty Nine: Use "73" and "88" incorrectly. Both are already considered plural, but add a "s" to the end anyway. Say "best of 73's" or "88's". Who cares if it means "best regards" and "love and kisses." Better yet, say "seventy thirds"! (By the way, seventy thirds equals about 23.3). Or talk like a 1960s CBer and sign off with "Threeeeeeees to ya!".

Step Thirty: If the repeater is off the air for service, complain about the fact that it was off the air as soon as it's turned back on. Act as though your entire day has been ruined because that one repeater wasn't available when you wanted to use it. Even thought you have never donated a penny to help out with the upkeep of it, and despite the fact that you have all 42 local repeaters programmed into your mobile radio.

Original post: http://www.repeater-builder.com/humor/how-to-sound-like-a-lid.html

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