I've repaired and aligned several of the Paragon and Paragon II radios.
This includes the ones I owned personally.
I always strived to set the BFO oscillators to be "dead nuts on" with an
accuracy of 1 Hz or better. There is some interaction between the
adjustments and I've found that going over the alignment for these some 3 or
4 times was found to be necessary. Since these "rocks" are not highly
temperature compensated some warm uptime is required and even then they will
vary with temperature. Specially true if running a high demand mode such as
RTTY that heats the inside of the case. My counter will capture the low
and high values over a period of time. I usually allow the radio to warm up
in receive with the cover on, make adjustments, lay the cover back on and
then allow it to warm again. Frankly I'm not sure how prudent this method
turns out to be. But I did spend several hours analyzing the drift of the
oscillators over time and over a temperature range.
The master osc is quite stable and is easy to adjust and it generally stays
put.
In general I felt that if I could get all bands to be less than +/- 50 Hz
that I had a good alignment job. What you find is about typical of my
notes. If you get it correct on 160M then it will be off by 2x that amount
on 10M. If you get it correct on 10 MHz then the error will be about as
you find, or about 30 Hz or less, depending on band. The further one gets
away from the 10 MHz reference the worse it gets either up or down.
The manual that I have states: "Frequency accuracy: +/- 50 Hz @ 25
degrees C." From this info looks like your results are quite good.
73
Bob, K4TAX
----- Original Message -----
From: "Mark Kenward" <k8vf_mark@centurytel.net>
To: <tentec@contesting.com>
Sent: Tuesday, March 25, 2014 6:59 PM
Subject: [TenTec] Help needed with Paragon II alignment
Greetings.
I recently got a Paragon II and it was out of adjustment. (Formerly
belonged to Federal Highway Dept?)
I set BFO's as well as possible.
Basically has to set fsk bfo's off a bit to get the LSB/USB/and CW
Transmit to be on freq. Which they now are. I dont use FSK.
Set reference oscillator frequency.
NOW, the rig works fine on transmit and receive, BUT:
tx/rx are right on freq at 10 mHz.
BELOW 10 mHz I am 10-30 Hz high.
ABOVE 10 mHz I am 10-30 Hz low.
The off set starts at -30 at 160 mtrs, closer as you go up in freq, till
10 mHz, then drops about 10 cycles more per band as you go up to 10
meters.
Obviously I have something buggered up.
The only other thing I adjusted was to set the PBT, which shouldnt affect
this, I do not believe.
The rig is rock solid, and doesn't drift, so I would like to get it spot
on.
Can anyone help me here?
Mark
K8VF
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