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Article: 27119 of rec.radio.amateur.misc 
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From: WFAUST@NOMVS.LSUMC.EDU (Wm. Bryant Faust, IV) 
Newsgroups: rec.radio.amateur.misc 
Subject: Re: Info-Hams Digest V92 #1117 
Date: 28 Oct 1992 08:04:23 -0800 
Organization: UCSD Usenet Gateway 
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Sender: daemon@ucsd.edu (The Devil Himself) 
Message-ID: <9210281604.AA23582@ucsd.edu> 
NNTP-Posting-Host: ucsd.edu 
 
> 
> Or you can use an extra pole on the dip switch for a tone on/off switch 
> and use the freed-up on/off switch as a band change.  Look at the 
> schematic of the synthesizer and the thumbwheels real carefully.  It's 
> not difficult to add 140-144 and 148-149.995 to the basic radio (it's 
> shipped from the factory with the Mhz switch 4-bit (as in 8421 binary values) 
> hard-wired on, and the 8-bit hardwired off.  A couple of trace cuts and 
> jumpers will restore the lost functionality - but it's not a job for the 
> timid or those without a fine tip in their Weller Solder Station (tm)).  Then 
> look at the schematic again and realize that there's a pin near the 
> 1mhz pin that is marked 10mhz (unlabeled on some schematics...) that is 
> hard-wired off...  Duplicate the decoupling resistor/capacitor and hook it 
> to the freed-up on/off switch and you now have a 140-149mhz radio in one 
> position and a 150-159mhz radio in the other position... 
> 
> I don't know if a similar synthesizer mod will work on a 3AT or a 4AT - as 
> I don't have one and have not seen a 3AT or 4AT schematic. 
 
It does, my 4AT covers 450 and 460 via this type of a mod.  Total 
bandwith of the transmitter is about 20 MHz. 
 
Bryant, N5GWF 
wfaust@nomvs.lsumc.edu 
 
 
 
 
