[ICOM] R-71A

[D C *Mac* Macdonald]

If I recall correctly, R L Drake Co also used an incandescent 
lamp in series with the receive input as a protection device. 
Some other manufacturers may have done the same. 
 
73 - Mac, K2GKK/5 
OKlahoma City, OK 





> Date: Mon, 2 Jun 2008 23:13:22 +0100 
> From: sdaitch at KUW.IBB.GOV 
> CC: icom at mailman.qth.net 
> Subject: [ICOM] R-71A 
> 
> After looking over an Icom R-71A and finding poor sensitivity, 
> I think I've discovered DS1 between the SO-239 antenna input and 
> the RF unit input at EP2 is open. 
> 
> It looks like Icom uses a mini-lamp of some kind as an overpower 
> protection unit for the RF input. Bypassing the DS1 and the 
> sensitivity appears about normal. 
> 
> None of the on-line information that I could see has the parts 
> breakdown for this unit. I suppose any really small lamp bulb 
> would work, but for purity sake, what is the trade number or 
> specs for the DS1 bulb? 
> 
> thanks, 
> 73 
> Sheldon 
> WA4MZZ