Re: S-85 refurbish: I've got a problem during the RF alignment of bands 1 and 2 - trimcaps don't peak!
¿ªÔÆÌåÓýEmanuele I NEED EDUCATION ?on reading these new scopes and such Wrt your previous post; I have no reason to believe there is a problem in the IF. My last post made wrong assumptions on the reading the scope, so my conclusions are wrong; and I agree the RF tuning on the first tank in band 1? is way out it seems. I keep wondering why 4 tanks seem to have the same problem. ?Is it possible that the bandspread dial stringing is reversed? ? From: [email protected] [mailto:[email protected]] On Behalf Of Emanuele Girlando via groups.io
Sent: Thursday, February 6, 2025 4:25 AM To: [email protected] Subject: Re: [HallicraftersRadios] S-85 refurbish: I've got a problem during the RF alignment of bands 1 and 2 - trimcaps don't peak! ? Don, here is my picture interpretation: ? Richard: ¡¤?????? "So, what is this about .5Mhz and 370 and 220 Khz? ". Those are the delta values between peak and the desired frequency as reported by the Delta marker (rounded). ¡¤?????? The IF alignment has been remade from scratch by using the "visual" approach (first 3 pictures). ¡¤?????? "The position of the peaks on the RF will be affected somewhat by the dummy load". If you meant the "dummy antenna" I fully agree. I'm gonna try the same test removing the dummy antenna from the equation. I'll report as soon as I get time to work on that. Correction to my previous post: "...all signals (and the noise as well) tend to disappear below .5MHz" should read "... below 1MHz" that is in the lower half of the band. ? Thank you guys! Emanuele (IU1KNR). ? -- don??? va3drl |
don Root