Re: FT980 dose not recieve
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Mistake
Hi, friends,
I have done the procedure on 23th page on Tech Suplement. At the begining the voltage was on 8 v. I moved the trimmer slowly up to 6 v with USB and Shift fully counterclockwise. Then switched to LSB and Shitf to clockwise and the voltage did not change.
What to do then?
El mié., 22 de sept. de 2021 a la(s) 10:39 PM, jose carlos leon via groups.io <josecarlosleon48@...> escribió: Hi, friends,
I have done the procedure on 23th page on Tech Suplement. At the begining the voltage was on 8 v. I moved the trimmer slowly up to 6 v with USB and Shift fully counterclockwise. Then switched to USB and Shitf to clockwise and the voltage did not change.
What to do then? El mié., 22 de sept. de 2021 a la(s) 11:40 AM, jose carlos leon via groups.io <josecarlosleon48@...> escribió: Very thanks, Mat and Dave for explanations. I have now the Tech Supplement and read the procedure about BFO VCV in pag 23. But now I have another question:
"I understand it could be a problem of shift of frequency in BFO due of out of value of the trimmer. BUT, why the left meter on the radio indicates a value, like it could be a final power state current?
Best regards, CP6CL
Dr. José Carlos León Ortega UDI- Universidad para el Desarrollo y la Innovación Tel. (591 3) 3422525
Santa Cruz - Bolivia
On Tuesday, September 21, 2021, 08:34:09 PM GMT-4, Dave Thompson <thompson@...> wrote:
The BFO VCV problem was described in the FOX TANGO newsletter in about 1984.? Thanks to N8TW for pointing this out.? I replaced the trimmer in my first FT-980 I bought in 1983.? That GT-980 is running strong at N4PL. Thanks to N8TW to pointing to the .Yaesu Tech Supplement page covering this...
Being out of range means the FT-980 does not receive.? The first notice of a problem is that the tone is not the same on LSB as on USB.? Thank goodness it is an easy fix,
73 Dave K4jrb?
-----Original Message-----
From: <[email protected]>
Sent: Sep 21, 2021 6:07 PM
To: <[email protected]>
Subject: Re: [Yaesu-FT-980] FT980 dose not recieve
I had to eventually replace this capacitor, as the original drifted completely out of range. It is very common. The capacitor is TC4001 ... it is located under a "can" with a hole to adjust. You can see if it is operating by putting a voltmeter on TP4004 (right near the cap): it should read between 3V to 6V depending on USB/LSB setting, and IF-Shift position. The adjustment procedure is called "BFO VCV", and you can find it on page 23 of the Technical Supplement in the files section. -- -Mat Breton, N8TW
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