Re: Still Kicking after 40 Years ...
|
Mat and FT-980 group,
That trimmer is a known problem listed in the Fox Tango newsletters about 1983 or 4.? My original FT-980 now at N4PL's had the problem and I replaced it with a better trimmer.? The old trimmer went bad and you could not set it.? Chip K7JA told me the later models had a better trimmer cap.
I suggest finding the old Fox Tango newsletters.? Carol at Fox Tango may have them.? There are numerous suggestions fox fixes,
73 Dave K4JRB
-----Original Message-----
From: Mat Breton
Sent: Mar 22, 2021 5:42 PM
To: [email protected]
Subject: Re: [Yaesu-FT-980] Still Kicking after 40 Years ...
Hi Fred,
That VCO trimmer is a known problem: I replaced mine about 5 years ago for exactly that symptom. Anecdotal evidence says that the flux bath Yaesu used before wave soldering results in contamination of the ceramic, which eventually causes the value to go out of range of adjustment. Not sure if that is true or not, but it matches the symptoms for sure. I don't see that issue with other older ceramic trimmers ... so I suspect it was something yaesu did ... or maybe another component value going out of range (unlikely).
If you know the approximate cap range the VCO wants, I recommend getting a smaller trimmer value in that range ... makes it easier to find the sweet spot. The stock value requires a bit of patience and skill sometimes.
Just my thoughts ...
--
-Mat Breton, N8TW
|
