Re: ten tec 1320 (reply long)


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Posted by:  dennis

Posted On:  06/07/02

Subject:  Re: ten tec 1320 (reply long)

Message Posted:
    In Reply to: ten tec 1320 posted by pat/k8len on 06/06/02

Hi Pat,

Having worked on MANY of those 13xx rigs, here
is my "Simple Alignment" sheet. I hope this helps
you. I'm responding to the list, as I'm sure
someone else can use it. DISCLAIMER: It may not
be perfect, but it works ! Use at your own risk......
blah....blah...blah. Hey.......let me know if it helps
you.
I suggest you follow the steps in order. The
alignment proceedure in the manual is silly and
confusing.
---------------------------------------------------------------
Tools needed - makes things SO MUCH easier:
A. - any Frequency Counter
B. - Wattmeter, or something to indicate power out.

Step 1 - Connect rig to an antenna, tune around
and find a CW signal. Peak the following
transformers for maximum signal strength.
L6, L18 - Receiver front end.
L7 - Receiver mixer.
L5 - IF Amp

Step 2 - L1 is the receiver BFO adjustement. This
sets the I.F. passband, pitch of the received CW note, AND the opposite sideband rejection. If
improperly set, you will hear both sidebands of
a signal (passband too wide).

Adjust L1 so that only the higher sideband (higher
side of zero-beat) is received. This should be
where the transformer slug is near the top of the
can, but not all the way up. Set the tone (pitch) that
is comfortable for your ears. When properly set,
you will only receive that sideband, meaning as
you tune lower in freq., and pass through zero
beat, very little - if any - of the opposite sideband
will be heard. The higher you adjust the slug, the
tighter the bandpass will be. You can hear the
bandpass "compress", for lack of a better word.
Once you have that set to suit your tastes, move
on to step 3, which is adjusting L14.

Step 3 - L14 is the transmitter offset. It sets the
transmitter to the same sideband as the receiver,
so that both are close to the same freq. Close is
good enough, since you will be doing this by ear.
While transmitting into a dummy load (I usually
just stick my finger on the antenna :>) , adjust L14
until the sidetone is the same pitch as the received
signal. (A signal generator is the easiest way, but
an on-air signal is good, just don't tranmit on top
of them. Switch between antenna and dummy
load). Match the tones with L14 as close as you
can by ear. Step 2 and step 3 will put your receiver
and tranmitter into alignment.

Step 4 - While transmitting into a dummy load,
adjust L12 and L13 for maximum power output.
At 13.8 VDC supply, power output should be
approx 4 watts.

Step 5 - RIT adjustment. Place a freq. counter
probe on R13 lead closest to Q4 transistor. Note
the freq. in receive mode. Now transmit into a
dummy load and note the freq. Turn the RIT shaft
until the freq. is the SAME during both transmit
and receive. Turning the RIT moves the receive
freq., so match the receive freq. with the tranmit
freq, which does not change. At this point, install
the RIT knob so that the pointer is on the mid-scale
mark at the 12 o'clock position. Tighten the set
screw.

Your 13xx rig is now properly aligned.
------------------------------------------------------------
NOTE: When transmitting into a SWR of higher
than 2:1, the final may go into oscillation - (the
sidetone becomes really "raspy"). This is due to
coupling between the toroids in the power
output filter. Push each of these toroids, 3 I think,
AWAY from each other - so that they "lean" away
from each other. This will reduce the oscillation
that occurs at higher SWR. These toroids are
located at the left rear corner of the board, with
the front panel facing you.

The TT13xx series is a classic example of how the
performance of a very good QRP rig is diminished
due to a POORLY written manual. Good luck !

73,
dennis
WB8WTU



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