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duplicating stations top of band;bottom of band
#7

(08-05-2016, 05:20 PM)tomt Wrote:  
(08-04-2016, 09:48 PM)Radioroslyn Wrote:  Something else comes to mind, check the LO frequency to be sure it's on the high side of the signal and not the low side.

being away from any repairs for about 35 yeas makes it kind of hard! do you mean set to high side of 455kc if I missed a wire or got one wrong in wrong place on the band switch could this cause my problem. man I used to think I could work on radios some of these old ones will challenge me Thank for your help. ps I was looking at you gallery and seen your 84b; I have  one like it I am working on I got into vintage about a year ago having fun!!

What mean is the lo frequency must be 455kc above the incoming rf signal. For instance if you dial is set at 800kc the lo fq should at 1255kc. LO fq= dial fq + IF fq (your IF is 455kc) LO fq of 1255kc is 455kc above the 800kc that the dial is set to. You can listen for it in another reciever with the ant lead near the mixer tube.
Connecting a wire in the wrong place probably won't shift the oscilltor to the other side of the IF but it could cause some other issues that might cause your image problem.
I've been at it since the '60s when I was a kid and lately I had several real butt kickers! That 660L and thev42-854 where no picnic. It takes a lot of perseverance for sure!
On the 84 you need to replace all of the ecaps/foil paper and all of the resistors except the ww in the bias circuit. Rewiind the primary on the ant and osc coils and it will work swell!

When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!

Terry


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RE: duplicating stations top of band;bottom of band - by Radioroslyn - 08-05-2016, 07:31 PM



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