Re: {Collins} Antenna tuner question



The 400hz is also used to run the autotransformer motor.  The 180L3 was also used e,tensively with the 618T, especially in earlier and retrofit installations.  Watch also for broken ferrite cores inside the ribbon inductor.


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-------- Original message --------From: Roy Morgan via Collins <collins@xxxxxxxxxxxxx> Date: 10/11/17  12:53  (GMT-07:00) To: Jim Pruitt <jpruitt67@xxxxxxxxx>, Collins <collins@xxxxxxxxxxxxx> Subject: Re: {Collins} Antenna tuner question 
Jim,

It is the 180L-2 or 180L-3, depending on whether the thing is equipped with
the antenna changeover relay or not.  (Yes, the 180L-2 and 180L-3 differ in
that the L-3, I think, has the antenna relay).

One problem with these things is that they require 24/28 volts to run most
things in there (2 amps) but also need 115 volts 400 cycles to run the
phase detection system that is essential for it to operate.  This voltage
needs to be of low  power only, it is not used as far as I remember to run
anything but the detection circuitry.  60 cycle power will not do the job!
The web site shown below indicates 15 watts.

The antenna relays are more than somewhat fragile, as is the vacuum
capacitor that is in there.  Dropping one of these quite heavy boxes is
both a danger to your toes, but also a danger to the relay and the variable
capacitor.  If your tuner rattles with broken glass, and it is the
capacitor, give up all hope of getting it to run.

Note that they are meant to operate in aircraft, so at altitude the
breakdown voltage requirements of the various parts influenced the design a
lot.  So... you may well be able to manage more power at normal human
altitudes than it was meant to handle at altitude.

Note also, the antenna it was meant to tune was quite short electrically
(at least for much of the HF frequency range - 45 to 100 feet) compared to
what a ham operator may have.  Just the same, if you can get one running,
I'd expect you wold be quite impressed with its performance.

These may have been used with the ART-13 transmitter, I'm not sure.  There
is an indication they were used with the 618S-1 and 618S-4 transceivers.

You can read a moderate amount about this magical box at:

 http://g3ynh.info/atu/180L3/man.html

That site includes a circuit diagram but neither the text shown nor the
diagram tell the name of the manual they are from!
A request to the Collins list in 2008 brought no responses.  I am sure
there is or was a manual for these, but a quick web search brings no other
good results.

Note: tuning an antenna AT the antenna feed point with a remote antenna
tuner, is simply NOT required. Search for and read (if you can) Reflections
III for full details.
Buy one for $183 on Amazon at
https://www.google.com/search?q=refkectuinss+III&oq=refkectuinss+III&aqs=chrome..69i57j0l5.4191j0j4&sourceid=chrome&ie=UTF-8
or search the web for the PDF version I was able to find some time ago (not
easily just now).

I"d be glad to learn of a source for the military manual for the 180L-2 and
180L-3.


-- 
Regards,
Roy

Roy Morgan
k1lky since 1958

-----Original Message-----
From: Collins [mailto:collins-bounces+jonesjames=imonmail.com@xxxxxxxxxxxxx]
On Behalf Of Jim Pruitt via Collins
Sent: Wednesday, October 11, 2017 12:41 AM
To: collins@xxxxxxxxxxxxx
Subject: {Collins} Antenna tuner question

Can someone tell me the Collins model number of the antenna tuners that
used a motorized roller drum with silver plated ribbon
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