Hi Steve,
It may be several things causing PLL unlock on just that VCO. It could be a
possible bad trimmer cap on that VCO covering PLL2 on some bad solder
connections. The common problem many times is diodes in the RX bandpass and
if they go bad it can turn on different VCO's covering other freq. and also
turning on some TX circuits. Something you may try is checking the
sensitivity to see if it is down on some of the bands, pointing to bad
diodes if it is not to specs. The receiver is usually noisy also if this
happens as several bands are turned on at once.
TNX.... Tim wd0fkc
www.midwest-technical.com
----- Original Message -----
From: "Steve London" <n2ic@arrl.net>
To: <yaesu@contesting.com>
Sent: Wednesday, December 22, 2004 12:17 PM
Subject: [Yaesu] FT-900 PLL Alignment ?
> I'm trying to help a disabled local ham get his FT-900 working right. It
> looks like PLL2, covering 7.5-14.5 MHz, has a problem and won't lock once
> the rig warms up.
>
> Can anyone help me with alignment instructions or a pointer to an online
> service manual ? Tried mods.dk, but it appears to be broken.
>
> Thanks,
> Steve, N2IC/5
>
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> Yaesu@contesting.com
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