[ARC5] Audio Booster

[Robert Eleazer]

For my attempt to boost the audio from the radio in my airplane I tied a little module available from All Electronics, their Catalog Number AMP-8403VC.  It is quite small, about twice the size of a postage stamp, has stereo capability and features a built in pot for a volume control that also has an on/off switch.  It runs just fine on three AAA cells.  Cost is $4.50 each.

I built the circuit into a metal box that had been the noise blanker for some 1960's vintage military receiver.  Input impedence measures about 48K ohms and output is supposed to be into 3 watts into 4 ohms.  

I had a bit of difficulty getting the amp to interface properly with the airplane radio. 600 ohm output,  and added a 2.4K resistor in parallels accross the input to try to fix that.  In the end the problem turned out to be the 3.5 mm audio cable not interfacing properly with the airplane jack.  I made another cable, 3.5mm on one end and 1/4 in stereo plug on the other and it started working well.  The 4 ohm output worked fine into the airplane 600 ohm headset.  I'll have to see how it does in flight.

So if you need some audio boost, one of these units might do the job for you.

73's!

Wayne
WB5WSV 
    

---
This email has been checked for viruses by AVG.
https://www.avg.com
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.qth.net/pipermail/arc5/attachments/20210306/c89c7834/attachment-0001.html>