[arm-allstar] Yet another USB FOB Modification

Scott Zimmerman n3xcc at zewireless.com
Sat Nov 15 12:40:36 EST 2014

 > One thing I always like to see is some LED's to indicate what is going on.
I likewise. This along with other reasons is why I brewed by own interface. It's nothing fancy, but 
it does have indicator LEDs, additional audio output filtering, (for driving a modulator directly) 
and USB failure detection.

Frankly I was tired of trying to locate modifiable FOBs, then go through the time and effort 
required to add all of the additional circuitry I thought necessary.

You can check out the USB-RIM here: http://www.repeater-builder.com/products/usb-rim.html


Scott Zimmerman
Amateur Radio Call N3XCC
474 Barnett Road
Boswell, PA 15531

On 11/15/2014 11:25 AM, Mark Herson, N2MH wrote:
> Yet, yet another comment on FOB mods...
> I've done a bunch here on pc prototype board. One thing I always like to
> see is some LED's to indicate what is going on.
> In addition to the green heartbead LED, I also include a red LED to
> indicate PTT and a yellow LED to indicate COR coming into the fob.
> The red LED needs another transistor in parallel to the usual PTT LED.
> This keys the red LED which is then connected to +5 VDC through a current
> limiting resistor.
> The yellow LED is connected from the incoming COR line through a current
> limiting resistor to +5 VDC. This limits the incoming COR to an active
> ground from the radio equipment. Fortunately, this protects the sound fob
> from an incorrect COR condition if the radio is turned off or otherwise
> disconnected from the FOB.
> +5 VDC is picked up from the sound fob.
> This whole topic reminds me of YAPP from the early days of packet radio.
> YAPP was a file transfer protcol customized for packet radio. YAPP stands
> for Yet Another Packet Protocol :-)
> 73, Mark, N2MH
> Allstar Node 40831
> ACID plus 2 BBB's and counting...
>> Date: Sun, 9 Nov 2014 02:11:25 -0500
>> From: Doug Crompton <doug at crompton.com>
>> To: "arm-allstar at hamvoip.org" <arm-allstar at hamvoip.org>
>> Subject: [arm-allstar] Yet another USB FOB Modification
>> Message-ID: <BLU172-W299469D7812B52ECE86A28BA830 at phx.gbl>
>> Content-Type: text/plain; charset="iso-8859-1"
>> Here is a link to my modification of the USB FOBS recently noted on this
>> list and available from ebay at $24 for a lot of 10. I will be adding
>> this link to the BBB web Page.
>> http://crompton.com/hamradio/usb_fob_modification/
>> 73 Doug
>> http://www.crompton.com/hamradio
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> Visit the BBB web page - http://www.crompton.com/hamradio/BeagleBoneBlackAllstar/

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