LED Voltmeter (for portable QRP ops)

As the summer is already here (HI), I plan to spend some time on YOFF and SOTA-YO so I prepare my portable backpack.
A portable and compact voltmeter is often nedeed but the usual multimeters are bulky, impractical and heavy (for portable use).
Therefore, I made a little voltmeter, which shows the SLA battery voltage via a blinking LED.
I made it around a PIC 16F876A microcontroller using the embedded ADC.
All can be made on a perfoboard as a Do It Yourself (DiY) Project for a raini afternoon.

Here is the schematic diagram (CLICK to enlarge):

The LED shows the following voltages;

Ind.	Volt	Collour
LED 1	< 11 V	Bright RED
LED 2	11 V - 12 V	RED
LED 3	12 V - 12,4 V	YELLOW
LED 4	12,4 V - 12,6 V	GREEN
LED 5	12,6 V - 13 V	GREEN
LED 6	13 V - 13,3 V	GREEN
LED 7	13,3 V - 13,8 V	YELLOW
LED 8	>13,8 V	Bright RED

Al the nedeed files are .rar archived and available for download HERE.

Here is a little movie with the voltmeter:



If you found this usefull, please drop a line!

73 de YO3HJV

PS
A explanatory article was published into the QRP Quarterly (Spring 2012) 
-Page 1
-Page 2 

Here is another link to download QRP Quarterly with SLA PIC Voltmeter.

Lustraphone mike, another piece of junk restored...

A few months ago I visit a friend of mine.
In his backyard I found a big stock of junk.
Searhing for some interesting, I found a nice desktop microphone who look a little odd!
I took it for nothing.
Unfortunately, I didn't took any picture before I start to open it. The images here are after some cleaning...
At home, after a little thinking, I opened it and found that the microphone is made by LUSTRAPHONE in England.
A nice transformer was fitted under the transducer. The output is balanced at around 600 Ohm.


I search on the Internet but I found almost nothing about this type. Only this site is exhibit a identical one, only for hire!
I removed the old paint which was horrible and sprayed with a matt-black one.
On the chromed pieces I work witha Dremel brush and restored the shining for a nice contrast.
The front of the transducer was covered with a dense copper mesh which was unrecoverable so I removed it.
The switch is the original one (Labeled also with LUSTRAPHONE). It is a double-section two position but one section was unusable (in shortcircuit) so I had to use only one...

The final result is this (click on photo for larger view):

I used it on a FT-2000 and the audio reports were great!
Nice piece...

Why Lustraphone Ribbon Mike was never at BBC.

Some info about LUSTRAPHONE:

Lustraphone was a contemporary of Grampian and Reslo from the 1950s -- all British microphone manufacturers building ribbon and moving-coil mics mainly for the amateur, semi-pro and PA industries. (http://www.soundonsound.com/sos/mar02/articles/qa0302.asp).

It seems that hey invented the noise cancelling microphone!

Ten things about ICOM IC-R20 (and more)

ICOM just announced that IC-R20 is not longer in production. 
I still have mine.

I have this pretty communication reveiver for more than 2 yrs. I had a lot of fun with and found a lot of use especially on my experiment bench but also to listen to various stations while travelling.
One of the main benefits is the enourmous autonomy from the LiIon battery which keep the receiver "alive" for more than one week. Of course, with some moderation to the loudspeaker volume and around 2 hrs/day listening.
The full characteristics of the ICOM IC R-20 "A.K.A. "features"are to be found on various places on internet so I do not want to trick you to land on my page for this, HI.
Instead, I will emphasize some of the features and some of the missings of this radio.

1. The SSB is missing above 470 MHz. This lead to impossibility to trace faint signals with a waterfall software (like Spectran or SpectraVue);
2. The excessive sensitivity of the front end sometime make impossible to listen to some signals in a strong RF environment; fortunately, the RF level CAN be applied simultaneous with the RF ATTenuator.
3. The memory and scanning is a little weird for someone used with transceivers. Banks and lists are too complicated but I believe it is hard to organise more than 1k slots.
4. A big plus is the "onboard" recorder though the audio format ( .icw) used is obscure and not supported by the programming software. One have to upload the recordings into the scanner and listen with the IC R20 which is stupid! really stupid. But there is solutions! The squelch-activated recording is a nice feature! The audio file format is weird but I have a conversion software (see links below)
5. The original antenna seems to be fragile but I didn't manage to broke. Yet! (still OK in May 2022)
6. The LCD screen is "the best". Simple and effective, visible in the full sun and also at night. The backlight is also, one of  the best I ever seen.
7. A high level of IMD above 1.5 GHz made this radio tricky to use on some SatCom. I didn't tried in remote places and Bucharest is not the best place for that kind of weak signal receiving.
8. The audio jack is shared with the CAT (CI-V) port. It is mandatory to have some kind of separation between when using headphones. Or to hack a headphone to use it. The built in speaker is not so loud so one will take benefit from a headset in noisy environments.
9. Excellent below 30 MHz and exceptional above 100 MHz; The BC receiving is very nice and the autotune is working well. The SSB is pretty like on a big transceiver.
10. Very quick on scanning memories. Also, the CTCSS/DCS scanning is working very nice.

OK for now...
What about the software? one will ask...

So, there is a programming softare. CS-20 is the "name". With this you will be able to programm the memories and banks. You will be able also to download the recorded communications.
To listen to that recordings is a different story but it is a solution.
You have to use a ICW2WAV utility (audio conversion software)
Also, a steady hand will be able to take the last IF (450 kHz) and send it to a SDR receiver to decode unusual modes while tuning above 1 GHz!
You can use Ham Radio Deluxe to controll the Icom IC R20. With DRM you will be able to decode most of the digital modes below 470 MHz and if you made the IF mod, you will be able to "unleash the beast"!

This are hard to find so, let's organise the files (links updated at 18 May 2022:

-Programming software CS-R20
-Service manual;

-Service manual Addendum;

-Icom R-20 modifications in one file.

-ICW2WAV audio file conversion software .

-If needed, here are OKI DLLs (OkiAudio.dll, OkiAdpcmEnc.dll, OkiAdpcmDec.dll). Unzip them and copy into the ICW2WAV folder. 

Please, be aware that the software is hosted on external server. 

Use a antivirus software to scan for problems before installing and make a  backup copy because I do not how much that will be there!

73 de yo3hjv

Later Edit

So, just happened! Told you to make backup copies!
Fortunately, I was able to find them again so, the links are updated (18 May 2022).

LLE (August 28, 2015)
After more than 3 years after the first impressions and tests with other scanners, I strongly believe that ICOM IC-R20 is the best comm. receiver.scanner at his category (portable/handheld). It's not cheap but the quality has a price!
The LiIon battery is doing fine, after this years keeping the radio running for a week or more on moderate use.
There are hardware mods to use a RTL SDR on first IF; one can have all modes on the entire receiving range but a very steady hand and good eyes to do it.
The original antenna is doing fine, beating the record on this kind of antennas!
I was sorry to heard that the rado is no more on production so, if you find one on stock somwhere, grab it before anyone else will do it.
Definetly, a keeper!

LLLE (May 2022)

I still have it. I can't find the battery holder skeleton but the original LiIon battery still hold the charge like a new one. 

The receiver is still in good shape altough the rubber caps are starting to worn and to show the age.

At some point I considered sell it and buy the new Icom IC R-30 but I am very pleased about this one.