[Fox_Tango] "Fix" circuit on FT-101E speech processor board

[Davis_R]

Hi Wiley,
The 'fix' circuit allows you to use a crystal, of the proper frequency,
inserted into the crystal socket on the processor board. The correct crystal
frequency is calculated from a formula and a table in the manual. When the
VFO switch is placed in one of the 'Fix' positions, the crystal takes place
of the VFO, and Viola -  fixed, crystal controlled frequency.  There is a
trimmer capacitor associated with each crystal position to tweak the
crystal, compensating for manufacturing tolerances, etc. Both transmit and
receive frequency are fixed, unless you use the clarifier, which behaves
normally, by shifting the receive frequency a couple of KHz to tune in
someone who is not quite on you.
A typical use for this would be net operation, or maybe a calling channel.
Another good use would be to get the proper crystal frequency to enable
reception of WWV at 15 MHz for those occasions when the 10 MHz signal isn't
quite getting it. You would just switch to 20 meters (if you are not already
there), switch to 'Fix', tune the preselector and he oughta be right there.

Sorry, can't help you with the RF problem, but which RF Processor do you
have? The 1534 or 1292 (I think that is the right number)? The 1534 is the
newer one, and used an external LEVEL control on the front panel, concentric
with the Clarifier. The older board, again I think it was a 1292, had the
Level adjustment on the processor board. The original FT-101E used the 1292
for about a year, maybe less. Realizing that the Level control needed to be
adjusted for each band, they moved the level control to the front panel.
They also brought the ALC onto the board to control the gain of the last
stage, added some more amplification, and used a different means of
clipping. Let me know which one you have and I can send you a schematic and
suggest an alignment procedure.

73
Rick, WD8JJA.

----- Original Message -----
From: "Wiley Sanders" <wsanders@wsanders.net>
To: <fox_tango@mailman.qth.net>
Sent: Thursday, March 13, 2003 8:49 PM
Subject: [Fox_Tango] "Fix" circuit on FT-101E speech processor board


> What's the purpose of the "Fix" circuit on the speech processor board? As
best
> I can tell, it provides clarifier capability when the frequency is under
> crystal control.
>
> I'm debugging reports of bad audio with my processor on, only on 10m. No
> reports of bad audio on lower bands. I'm pretty sure it's RF getting into
the
> radio; I didn't hear any complaints until I added 5 feet of feedline onto
my
> antenna so it would tune up on the 10m CW band. Now there's RF in the
shack on
> 10, just enough to freak out my digital thermometer and occasionally lock
up
> my computer keyboard.
>
> Just to make sure I thought I would run through the alignment procedure
for
> the audio processor. It's not very well documented - I've determined that
the
> Red coax is audio in, Yellow is audio out, and green is "Fix" output.
>
> -Wiley Kf6iiu
>
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