In ultima saptamana am avut ocazia de a testa o statie portabila Hytera PD-785G, varf de lance in gama de statii portabile a firmei chineze.
Sunt destul de reticent cand vine vorba de statiile produse de chinezi insa Hytera se dovedeste a fi o firma cu planuri ambitioase ce a cumparat divizia de radiocomunicatii profesionale de la celebra Rhode & Schwartz, demonstrand ca doreste sa devina un jucator serios in piata DMR si TETRA.
Ca aspect, PD-785G are un design modern, apropiat de terminalele portabile Tetra; carcasa este realizata din policarbonat, in doua nuante de gri.
Ecranul este generos, color, afisand informatiile necesare utilizatorului, inclusiv nivelul de semnal si starea bateriei precum si sincronizarea cu satelitii GPS - pentru versiunea "G".
Incarcatorul este de tip "drop in", operarea fiind simpla si intuitiva.
Spre deosebire de Motorola, a carei gama "Intellicharge" furnizeaza informatii extinse despre acumulator, acesta este simplu, indicatia incarcarii realizandu-se cu un LED bicolor.
Antena este amplasata in mijlocul partii superioare, intre butonul de volum si comutatorul de canale.
Din acest motiv, aspectul este usor diferit de cel cu care suntem obisnuiti sa il intalnim la statiile portabile, accentuand aspectul particular al PD-785G.
Antena se conecteaza la statie printr-un conector tip SMA-Reverse, ceea ce inseamna ca vom avea nevoie de un adaptor SMA-mama <> SMA-mama pentru a conecta o antena externa.
Tot in partea de sus se gaseste si un buton orange, de regula utilizat pentru anuntarea unei urgente si punerea statiei in mod automat de funtionare.
Spre deosebire de competitorul direct, Motorola, selectorul de canale are doar 16 pozitii. Desi poate parea vetust, numerotarea canalelor poate fi de ajutor atunci cand dorim sa verificam canalul pe care este statia fara sa o mai scoatem de la centura. O singura privire la selector ne informeaza pe deplin.
Tot in partea superioara se afla un LED care ofera indicatii cu privire la traficul radio in frecventa selectata.
Chiar deasupra ecranului este o mica perforatie pentru microfon; prima reactie a unui amic radioamator a fost sa intrebe daca acolo este difuzorul si daca statia poate fi utilizata ca un telefon mobil ori ca o statie Tetra.
Difuzorul se afla in spatele tastaturii numerice, chiar sub tastele de meniu si, desi deschizatura pare insuficienta, cutia de rezonanta astfel realizata asigura claritate si volum suficient chiar si pentru utilizarea in medii zgomotoase cum este, de exemplu, utilizarea in mobil.
Tastele sunt din cauciuc si nu din plastic cauciucat cum intalnim la majoritatea statiilor chinezesti, si furnizeaza un feedback tactil clar dar discret.
Tastatura este retroiluminata insa, pentru conservarea energiei, retroiluminarea este activa in mod curent doar la ecran; numai la accesarea meniului se aprind si LED-urile de sub tastatura numerica.
In laterala stanga se afla tasta PTT si doua taste programabile. Prin intermediul soft-ului de programare se pot aloca diverse functii acestor doua taste, cum ar fi: modificarea puterii de emisie, scanare, modificarea treptelor de squelch samd.
Tasta PTT este inconjurata de o garnitura orange si este amplasata intr-o protuberanta de protectie.
Tot pe latura stanga, in partea inferioara se afla o eticheta cu modelul statiei.
Pe latura din dreapta se gaseste conectorul de accesorii. Acesta este acoperit de un capac de protectie, realizat din cauciuc. Spre deosebire de alte statii profesionale, la Hytera PD-785, capacul este fixat de corpul statiei printr-o balama.
Personal, consider ca aceasta solutie este mult mai buna comparativ cu fixarea printr-o "codita" cauciucata care, mai devreme sau mai tarziu se va rupe si va duce la pierderea protectiei.
Pentru siguranta, capacul de protectie se imobilizeaza in pozitia "inchis" cu ajutorul unui surub cu profil redus.
Hytera PD-785 poate fi echipata cu un suport de fixare la curea, care se monteaza direct pe corpul statiei, pe o decupare de aluminiu. Gasesc foarte inspirata alegerea, spre deosebire de solutia Motorola, care a decis sa amplaseze clips-ul de curea pe spatele bateriei!
Un plus, neesential pentru functionarea statiei dar pentru precizia prelucrarii, este faptul ca nu exista niciun joc mecanic intre statiei si baterie!
Bateria cu care vine echipata statia este LiIon, 7,4V / 2000mAh, existand posibilitatea echiparii cu o baterie extinsa, de 2500mAh.
Durata de exploatare a bateriei este superioara statiei Motorola DP4801 cu care am facut unele comparatii in utilizare. Spre deosebire de Motorola, Hytera PD-785 poate fi utilizata doua zile pe bateria standard si circa 3 zile cu cea extinsa, in utilizare moderata, mixt analogic si digital.
Desi statia este, in principiu, programabila cu ajutorul calculatorului, exista posibilitatea de a programa o serie de parametri utili direct din tastatura, cu conditia activarii acestei optiuni in softul de programare. Putem programa frecventa canalului radio, ID-uri ale corespondentilor dar nu si CTCSS.
In "lumea reala", statia se prezinta bine, fiind suficient de sensibila si avand o buna procesare a semnalului inclusiv pe calea analogica.
Desi sunt unele voci care critica antena cu care statia vine echipata, personal nu am nimic de reprosat acesteia. E foarte posibil ca utilizatorii nemultumiti sa nu fi selectat gama de frecvente corecta.
Cum spuneam si mai sus, prezenta unui conector de antena este un plus pentru cei care doresc sa utilizeze statia si in mobil. Pentru ei, exista un suport auto care permite incarcarea bateriei pe durata utilizarii statiei.
Rapoartele de receptie sunt incurajatoare si nu releva nimic suspect; neanuntati, corespondentii nu au remarcat diferente intre Motorola si Hytera PD-785G.
Per ansamblu, statia este o alternativa pertinenta la rivala mult mai scumpa de la Motorola, DP-4801. Este o statie robusta, de calitate, receptia si emisia rivalizand cu orice alt competitor din gama de varf; politica de vanzare cu pret preferential catre radioamatori a dus la proliferarea Hytera PD-785G in randul utilizatorilor retelei MARC-DMR.
Pentru cei care au restrictii la bugetul destinat echipamentelor HAM, statia se prezinta si in versiunea fara GPS (PD-785), pretul ajungand astfel la aproximativ 60% din cel al unei statii Motorola DP-4801.
Chiar daca nu este "Statia", Hytera PD-785G este o alternativa serioasa, in opinia mea fiind varful in clasa de statii DMR de buget redus.
73 de Adrian, YO3HJV
Completare (26 august 2015)
Prin update FW, s-au rezolvat o serie de probleme, in special legate de FPP. Acum se poate programa si CTCSS, distinct pe Rx fata de Tx!
De asemeni, o facilitate pe care nu am gasit-o la Motorola este "Pseudo Trunk", care poate fi activata via FPP si care permite ascultarea simultana a TG-urilor active pe AMBELE TIMESLOT in frecventa respectiva! E ca si cum statia ar scana canale cu TS diferit, facilitate extrem de utila pentru monitorizarea TG internationale si a celor locale.
26 decembrie 2014
25 decembrie 2014
Hytera PD-785G review
My DMR radio collection y has grown by adding two Hytera radios; one is
the flagship PD-785G and the second one is the small PD-365.
I was very reticent about chinese radios but the recently increase in the number of users of Hytera on MARC-DMR network made me raise the elbow and I promised myself that I will not miss the chance to test one.
We’ll review the first one for the start.
Look and feel
Front
PD-785G is a little smaller than the direct competitor,
Motorola DP-4801 and look more like a Tetra terminal than like a conventional
radio.
With the central mounted antenna, the radio looks somehow
unfamiliar and Hytera pretend that this design help improve the RF performance.
Well, I read somewhere that the antenna is not so good but after a week of
testing I admit that is not better than a longer antenna but at it’s dimensions
is not worst than the 9 cm one from Motorola.
On the front pannel we have a big colour LCD and above it is
a little hole for the microphone. First reaction of a fellor ham was to put the
radio to the ear as the microphone looks pretty like the earphone of a mobile
phone.
Right under the screen are the menu keys and a big
directional key, only for up and down (at DP-4801, there are also Left-Right on
the same key). Under that, we have the numeric keypad.
What is particular to this model is that the speaker is
UNDER the numeric keyboard; a long slit is between the menu and numeric keys
and there is the speaker.
Left side
The PTT has a nice orange gasket around and feel a little
fragile. The two programmable butons feel ferm and cannot be pressed by
accident; they need some determination to have them pushed.
In the CPS you can program them with a lot of functions, one
for quick press and one for long press but I found that the combination is
available only for certain functions not for any of them and once programmed, there are some bugs that make that
button not functional. Maybe is just a firmware problem but tend to be
annoying!
Under the buttons is a little plastic plate which identify
the model. Mine is a “G” one, with GPS.
Right side
On the right side of the Hytera PD-785G we find an accessory
connector. This one is half of the Motorola’s and the cover is hinged so,
goodby loosing it! Of course, if you are determined, you can break the hinge
and throw away the cover!
There are some sort of grip helpers on the side of the radios but despite the look, they are made by the same plastic as the whole case and not of rubber as one may expect from the look.
Upper side
On the top of the radio we have the two knobs, VOL/ON-OFF
and the Channel selector. The channel selector is an interesting thing; it has
16 positions. This might look a little obsolete but I do find it usefull
especially when the radio is on the belt. You can find the channel with a
glimpse at the channel knob.
Also on the top, just near the channel selector is an orange
button for emergencies. This one can be programmed as the other ones, with the
same observations…
In the right side, near the Vol/On-Off is the status LED; a
little protuberance make it visible even if you look to the radio directly from
the front side.
The antenna is between the knobs, as I said before, givind
an unusual look to the radio.
The antenna connector is a reverse SMA. The reverse SMA connector is a nice touch and permit us, the
hams, to put a better antenna or even to connect a mobile antenna to this radio
for a better coverage.
Back
The battery attach not by sliding and there is no gap
between the battery and the radio! Once attached, there is no jolt or lost motion
between them (shame Motorola!).
The belt clip is attached to the radio and not to the
battery. On the radio is a metal plate and the belt clips attached with two M4
screws in the old way. I like this, it’s very solid!
The stock battery is a 7.4V/2000mAh and the battery life is
better than the Motorola’s. With the stock battery at a moderate use, on analog
channels and digital channels, the radio can be used for two days with no
problems. With an optional 2800MAh battery I used it for about 3 and a half
days.
I will not enter in the subtilities of programming the
radio, this is a little complicate and depends on what do you want to do with
the radio so I will emphasize some of the bugs or the features of the radio.
Bug: The audio
amplifier is not balanced and is powered on receiving. This express with a loud
“bop” even at low volumes when the radio start to receive traffic. Motorola has a balanced AF amplifier…
Feature: When rotate the
knob or press any key (but not the Menu
key or the numeric keys), only the LCD fire up. The backlight of the numeric
keys stays off. This can save some
battery!
Bug: The radio cannot scan digital and analog channels at
the same time. You can scan channels on the same kind only. Motorola can scan
combined lists.
Feature: When receiving, the radio starts the LCD backlight.
Very usefull to see what’s happening on the digital channels.
On the traffic, the radio is sensitive and the quality of
audio is very good on both analog and digital. I see no differences on
digital when compared with Motorola with
the latest firmware (2.4.x).
The audio reports on modulation were good and, during the
tests I found that the scrambler is higly compatible with Motorola’s.
Understandable because is a simple inversion…
The radio is not a bad one but is not “The radio”. Some bugs
can be solved via firmware upgrade but others are “hardware defined” and need redesign.
The GPS has a nice feature by wich the user can send as a short message the
position.
The missing Bluetooth can be a shortage as I programm my
DP-4801 via Bluetooth (the Motorola programming cable is too expensive!) but
the Hytera cable is affordable at a half of the Motorola’s price so the absence
of BT is not a real problem for me.
If the price is a key component in the buying decision, the
Hytera PD-785G can be the best choice as the price/quality is unbeatable.
It is compatible with the MARC-DMR network except the short
messages but the latest firmware updates for Motorola radios and repeaters
which let the user choose between Motorola proprietary and DMR standard open
the door for full compatibility between Hytera and Motorola networks.
The quality of the hardware is much better than other Chinese
radios and i expect to be better and better after Hytera bought Rhode & Schwartz Professional Mobile Radio division!
The policy to sell radios for hams at a low price is a good
impulse for us to explore the future of the telecommunications.
I will not trade the DP-4801 for a Hytera PD-785G but I
certainly use this radio day by day!
73 de Adrian YO3HJV
12 decembrie 2014
Home made IF Filter
Today I started wondering what should I do with some quartz cristal that I have around...
A IF filter was my first thought and I started to fool around with them.
First, I cut a small piece of PCB and prepared for "dead-bug" soldering style.
I prepared also two small piece of RG58U to connect the filter to a Marconi IFR analyzer.
In my box I had two type of cristals.
One type is a 4 MHz and the second one is a 38.9 MHz, both of them HC-49U format.
First I started with the 4 MHz ones but I didn't noticed a nice shape on the analyzer so I quicly moved around to 38.9 ones.
These are overtone cristals so I watched to fundamental frequency which had to be around 12.6 MHz.
And it was!
I don't want to bother you with math stuff. Instead, I will put the self-explanatory pictures.
The two SMD resistors are 470 Ohms and the small SMD capacitors are 1nF.
Here it is the filter on the tests. After tests, it can be put on a smaller and nicer board. I didn't had capacitors, I will play with them monday, HI.
There are 9 cristals. At less than 1 USD, I believe is a good alternative!
Indeed, one had to choose from a big bunch, but I had an already opened bag of cristals with around 25 pcs. I observed on the analyzer that there was two type of shape for that bunch.
The insertion loss is around -4db wich is not bad at all!
The center frequency was set at 12.96400 MHz. This might be somehow unusual for elder hams but with modern DSS it's easy to set the IF to this value.
-22db attenuation at +1.5 kHz
-27 db attenuation at - 1.5 kHz
It has a passband of around 1.8 kHz at -15 db. Maybe I will send it to some experimenter who want to play with because I am very curious about how it sound in the real HF traffic!
Other pictures:
A IF filter was my first thought and I started to fool around with them.
First, I cut a small piece of PCB and prepared for "dead-bug" soldering style.
I prepared also two small piece of RG58U to connect the filter to a Marconi IFR analyzer.
In my box I had two type of cristals.
One type is a 4 MHz and the second one is a 38.9 MHz, both of them HC-49U format.
First I started with the 4 MHz ones but I didn't noticed a nice shape on the analyzer so I quicly moved around to 38.9 ones.
These are overtone cristals so I watched to fundamental frequency which had to be around 12.6 MHz.
And it was!
I don't want to bother you with math stuff. Instead, I will put the self-explanatory pictures.
The two SMD resistors are 470 Ohms and the small SMD capacitors are 1nF.
Here it is the filter on the tests. After tests, it can be put on a smaller and nicer board. I didn't had capacitors, I will play with them monday, HI.
There are 9 cristals. At less than 1 USD, I believe is a good alternative!
Indeed, one had to choose from a big bunch, but I had an already opened bag of cristals with around 25 pcs. I observed on the analyzer that there was two type of shape for that bunch.
The insertion loss is around -4db wich is not bad at all!
The center frequency was set at 12.96400 MHz. This might be somehow unusual for elder hams but with modern DSS it's easy to set the IF to this value.
-22db attenuation at +1.5 kHz
-27 db attenuation at - 1.5 kHz
It has a passband of around 1.8 kHz at -15 db. Maybe I will send it to some experimenter who want to play with because I am very curious about how it sound in the real HF traffic!
Other pictures:
06 octombrie 2014
25 septembrie 2014
LiIon charger with LM317 and Cutoff circuit - Part I
Very often I need to charge one or two series LiIon cell for my experiments.
I do have a sophisticated battery charger and analyzer but I don't want to use it every time.
I need something simple yet safe.
There fore I came to a nice shematics here.
It is a very simple schematics using just one LM317 and two NPN transistors.
I made some modifications.
The most important is R7 which is 6 Ohm for a 210 mA current.
Despite the urban myths, the Li based batteries are very safe at charging if you respect two rules:
1. No more than 4.2 V per cell
2. No more than 1.5 C (thats 1.5 x Nominal capacity in A) charging current.
The main advantage is that at the end of charging, when the battery has the desired voltage - in our case, 4.2 V/Cell, the charging current drops to zero. The bonus is that the LED lights during the charging phase.
Yes, I know, there is CAD but I like the old fashion way to make a PCB. By hand with a fine marker...
Here are some pictures....
I plan to put this with a 12V/2A SMPS into a small box.
I do have a sophisticated battery charger and analyzer but I don't want to use it every time.
I need something simple yet safe.
There fore I came to a nice shematics here.
It is a very simple schematics using just one LM317 and two NPN transistors.
I made some modifications.
The most important is R7 which is 6 Ohm for a 210 mA current.
Despite the urban myths, the Li based batteries are very safe at charging if you respect two rules:
1. No more than 4.2 V per cell
2. No more than 1.5 C (thats 1.5 x Nominal capacity in A) charging current.
The main advantage is that at the end of charging, when the battery has the desired voltage - in our case, 4.2 V/Cell, the charging current drops to zero. The bonus is that the LED lights during the charging phase.
Yes, I know, there is CAD but I like the old fashion way to make a PCB. By hand with a fine marker...
Here are some pictures....
I plan to put this with a 12V/2A SMPS into a small box.
09 septembrie 2014
Kantronics KAM Plus
So...
I found on my junk box a Kantronics Kam Plus modem. It stayed there about 2 years untill I found (yes, in my other junkbox) a 25 to 9 pin COM adapter...
I connected to a terminal and nothing happened, just garbage on my screen so I search on internet and came to this reset procedure:
1) Open the case
2) With modem power off, install Reset Jumper, K6 (near the largest IC), on the two posts. ( no need to touch the battery).
3) Using terminal program (WinPack or others) with baud rate set to 1200, power on the modem.
Modem should respond with :
CHECKSUM OK
....RAM OK
128K BYTES
REPLACE TEST JUMPER
4) Power off the modem; return jumper K6 to one pin only.
5) Power up the modem; Watch for:
PRESS (*) TO SET BAUD RATE* (You must do this within 2 seconds).
ENTER YOUR CALLSIGN=>
ENTER YOUR CALLSIGN=> yo3hjv
yo3hjv
KANTRONICS ALL MODE COMMUNICATOR PLUS Version 8.2P
(C) COPYRIGHT 1988-1997 BY KANTRONICS INC. ALL RIGHTS RESERVED.
DUPLICATION PROHIBITED WITHOUT PERMISSION OF KANTRONICS.
cmd:
You should now be in NEW USER mode.
6) Check your call sign by typing MYCALL
8) To change from NEWUSER mode to TERMINAL mode type INTERFACE TERMINAL
cmd:in terminal
in terminal
INTFACE was NEWUSER
cmd:
9) To change from 1200 baud (because Airmail doesn't go that slow) type in ABAUD 0
cmd:abaud 0
abaud 0
ABAUD was 1200
cmd:
Now, everything is ok , awaiting a proper radio and setup to test. Unfortunately, only CW and RTTY seems to be appropiate in these days since PACTOR, AMTOR and other modes like that ceased in favor of PSK.
Maybe this nice modem will find it's place as a APRS digipeater, who knows!
I found on my junk box a Kantronics Kam Plus modem. It stayed there about 2 years untill I found (yes, in my other junkbox) a 25 to 9 pin COM adapter...
I connected to a terminal and nothing happened, just garbage on my screen so I search on internet and came to this reset procedure:
1) Open the case
2) With modem power off, install Reset Jumper, K6 (near the largest IC), on the two posts. ( no need to touch the battery).
3) Using terminal program (WinPack or others) with baud rate set to 1200, power on the modem.
Modem should respond with :
CHECKSUM OK
....RAM OK
128K BYTES
REPLACE TEST JUMPER
4) Power off the modem; return jumper K6 to one pin only.
5) Power up the modem; Watch for:
PRESS (*) TO SET BAUD RATE* (You must do this within 2 seconds).
ENTER YOUR CALLSIGN=>
ENTER YOUR CALLSIGN=> yo3hjv
yo3hjv
KANTRONICS ALL MODE COMMUNICATOR PLUS Version 8.2P
(C) COPYRIGHT 1988-1997 BY KANTRONICS INC. ALL RIGHTS RESERVED.
DUPLICATION PROHIBITED WITHOUT PERMISSION OF KANTRONICS.
cmd:
You should now be in NEW USER mode.
6) Check your call sign by typing MYCALL
8) To change from NEWUSER mode to TERMINAL mode type INTERFACE TERMINAL
cmd:in terminal
in terminal
INTFACE was NEWUSER
cmd:
9) To change from 1200 baud (because Airmail doesn't go that slow) type in ABAUD 0
cmd:abaud 0
abaud 0
ABAUD was 1200
cmd:
Now, everything is ok , awaiting a proper radio and setup to test. Unfortunately, only CW and RTTY seems to be appropiate in these days since PACTOR, AMTOR and other modes like that ceased in favor of PSK.
Maybe this nice modem will find it's place as a APRS digipeater, who knows!
29 august 2014
My Dream "GO-BOX" for emergency communications. Or just for fun!
Well, I sibscribed recently to a FB group dedicated to emergency communications. Its a very nice group.
I do not believe in the FB because it's like the sand. You write something or find something but soon it's hard to find it again.
I like very much to have the possibility to go somewhere and try to make some QSO's. I am not a contester and I appreciate a nice chat with a fellow ham from here or anywhere. Therefore, I realise i really need a "GO-BOX" or a "GO-KIT" able to work all mode, all frequencies from HF to UHF.
Also the kit will be good for RVSU which is a network of hams involved in emergency communications for various NGO's here.
I will tell you my secret: My GO-BOX is on wheels!
It's a Nissan X-Trail "doped" with a lot of ham-stuff.
The main radio is a ICOM IC-7000 mounted in the trunk and the front panel remote. I finally made the permanent setup; the radio is under the trunk hood, bolted with the optional DC filter (OPC-639) and on the HF side I put a choke Balun to reduce the common mode currents from the Codan antenna (or any othe HF antenna) because the IC-7000 remote head is very sensitive to that issue.
The remote head is under the radio; i put it in place with the help of some industrial 3M velcro. In the left side is a small loudspeaker connected to the remote head. I use that velcro also for phones, portable radios etc...
The main attractions is the Codan 9350 auto-tuning antenna. Bulky but with outstanding performance, it's definetly a magnet for everyone's eyes, in march or in parking lot!
I wrote in other post about the custom mount for this antenna and about the connection with ICOM IC-7000 radio.
What I did lately was to put all the important wires in a protection harness.
The main 12V DC is in harness, the RG58 and the command cable for the ATU antenna is in the harness also. Was a little tricky but the final result is amazing!
For VHF and UHF I use quarter wave antennas. I found that if I put a quarter wave on VHF, the same antenna is resonant also in UHF! A MMANA-GAL simulation showed that the UHF angles are somehow elevated but still a +2db at 0-15 deg. over the horizont so the antenna can be used well.
I preffer NMO (New Motorola Mount) for my mobile antennas. This is a special designed mount to accomodate proffessional antennas ant to whitstand to all the special conditions on a mobile setup in full run. Do not ignore that! And also, keep in mind that a fixed mount is BETTER than any magnetic mount.
Here it is a NMO mount, VHF quarter wave antenna.
Now, for really serious things like emergency comms., I have a little toolbox with a 35 Ah SLA battery.
I was looking for a good battery eliminator but the price was too high and had to buy it from overseas! Hey, I think a little here and I know how to use a solder iron. Or solder station. Or something like that, you figure out...
So I made a very very simple "battery eliminator" or "separator", whatever, from a Schottky power diode. It was a bulky one, I don't know at what current is rated but did'nt burned at 14-16 Amps so must be better than that. In the little Hammond box I put a little 5 LED voltmeter to quick view the main battery status.
The later addition was a little digital voltmeter on a "Y" cable to view the voltage. Both of them are usefull.
The battery have two fuses, one for plus and one for minus.
Some hams think that if they put a single fuse, on the plus side, is enough!
Well, what if you make a shortcircuit between minus cable and the "plus" pole?
That toolbox cand accomodate the ICOM IC-7000 or anything else. In this setup made for Ciucas Trail Running (a 100 km mountain marathon) I have two Motorola mobile radios.
The lower is a GM360 VHF radio to talk to Salvamont (Mountain Rescue) teams and the upper is a DM3600 to use it with the Radioamateurs in the RVSU network (Radioamateurs for Emergency
Communications).
In order to be able to use a single antenna, a diplexer is used. Is a Diamond 2000 with modified RF cables. The original ones was too bulky and used PL and N connectors.
A lot of hams use amateur equipments for frequencies above the 146 or 148 MHz. They tend to ignore that out of the regular amateur bands, the radios are very ineffective!
I measured a lot of radios and they seems to loose power after 150 MHz and become very insensitive over 155 MHz. That's how they are made... So, in a emergency network I found a little stupid to use deaf and mute radios! Therefore, I will go with proffessional radios for that particular case and the choice is Motorola!
A completion to my HF setup is a AH4 ATU with a collection of wires. I use two lenghts, 8,5 m and 4 m as they are not half-wave, as reccomended by ICOM to use them with AH-4.
The trick here is that I made two lenght of control cable and RF cable (tied together) so I can use 5m or 10m from radio to AH4.
The AH4 can be used for tuning a horizontal antenna (dipole) or a vertical one (erected on a fishpole stick) using 2 equal wires or 4 counterpoises with a vertical radiator. That's why there are 5 cables at the same lenght...
Well, this is my GO-BOX!
4 wheels and radios!
For final, here it is with a strange VHF antenna on the rooftop!
I do not believe in the FB because it's like the sand. You write something or find something but soon it's hard to find it again.
I like very much to have the possibility to go somewhere and try to make some QSO's. I am not a contester and I appreciate a nice chat with a fellow ham from here or anywhere. Therefore, I realise i really need a "GO-BOX" or a "GO-KIT" able to work all mode, all frequencies from HF to UHF.
Also the kit will be good for RVSU which is a network of hams involved in emergency communications for various NGO's here.
I will tell you my secret: My GO-BOX is on wheels!
It's a Nissan X-Trail "doped" with a lot of ham-stuff.
The main radio is a ICOM IC-7000 mounted in the trunk and the front panel remote. I finally made the permanent setup; the radio is under the trunk hood, bolted with the optional DC filter (OPC-639) and on the HF side I put a choke Balun to reduce the common mode currents from the Codan antenna (or any othe HF antenna) because the IC-7000 remote head is very sensitive to that issue.
The remote head is under the radio; i put it in place with the help of some industrial 3M velcro. In the left side is a small loudspeaker connected to the remote head. I use that velcro also for phones, portable radios etc...
The main attractions is the Codan 9350 auto-tuning antenna. Bulky but with outstanding performance, it's definetly a magnet for everyone's eyes, in march or in parking lot!
I wrote in other post about the custom mount for this antenna and about the connection with ICOM IC-7000 radio.
What I did lately was to put all the important wires in a protection harness.
The main 12V DC is in harness, the RG58 and the command cable for the ATU antenna is in the harness also. Was a little tricky but the final result is amazing!
For VHF and UHF I use quarter wave antennas. I found that if I put a quarter wave on VHF, the same antenna is resonant also in UHF! A MMANA-GAL simulation showed that the UHF angles are somehow elevated but still a +2db at 0-15 deg. over the horizont so the antenna can be used well.
I preffer NMO (New Motorola Mount) for my mobile antennas. This is a special designed mount to accomodate proffessional antennas ant to whitstand to all the special conditions on a mobile setup in full run. Do not ignore that! And also, keep in mind that a fixed mount is BETTER than any magnetic mount.
Here it is a NMO mount, VHF quarter wave antenna.
Now, for really serious things like emergency comms., I have a little toolbox with a 35 Ah SLA battery.
I was looking for a good battery eliminator but the price was too high and had to buy it from overseas! Hey, I think a little here and I know how to use a solder iron. Or solder station. Or something like that, you figure out...
So I made a very very simple "battery eliminator" or "separator", whatever, from a Schottky power diode. It was a bulky one, I don't know at what current is rated but did'nt burned at 14-16 Amps so must be better than that. In the little Hammond box I put a little 5 LED voltmeter to quick view the main battery status.
The later addition was a little digital voltmeter on a "Y" cable to view the voltage. Both of them are usefull.
The battery have two fuses, one for plus and one for minus.
Some hams think that if they put a single fuse, on the plus side, is enough!
Well, what if you make a shortcircuit between minus cable and the "plus" pole?
That toolbox cand accomodate the ICOM IC-7000 or anything else. In this setup made for Ciucas Trail Running (a 100 km mountain marathon) I have two Motorola mobile radios.
The lower is a GM360 VHF radio to talk to Salvamont (Mountain Rescue) teams and the upper is a DM3600 to use it with the Radioamateurs in the RVSU network (Radioamateurs for Emergency
Communications).
In order to be able to use a single antenna, a diplexer is used. Is a Diamond 2000 with modified RF cables. The original ones was too bulky and used PL and N connectors.
A lot of hams use amateur equipments for frequencies above the 146 or 148 MHz. They tend to ignore that out of the regular amateur bands, the radios are very ineffective!
I measured a lot of radios and they seems to loose power after 150 MHz and become very insensitive over 155 MHz. That's how they are made... So, in a emergency network I found a little stupid to use deaf and mute radios! Therefore, I will go with proffessional radios for that particular case and the choice is Motorola!
A completion to my HF setup is a AH4 ATU with a collection of wires. I use two lenghts, 8,5 m and 4 m as they are not half-wave, as reccomended by ICOM to use them with AH-4.
The trick here is that I made two lenght of control cable and RF cable (tied together) so I can use 5m or 10m from radio to AH4.
The AH4 can be used for tuning a horizontal antenna (dipole) or a vertical one (erected on a fishpole stick) using 2 equal wires or 4 counterpoises with a vertical radiator. That's why there are 5 cables at the same lenght...
Well, this is my GO-BOX!
4 wheels and radios!
For final, here it is with a strange VHF antenna on the rooftop!
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