Re: {Collins} KWS-1, Up & Running----700 Watts+ Output on 75 Meters

Go get em. I am behind you a couple of months.



-----Original Message-----
From: Collins [] On
Behalf Of Chuck Curran
Sent: Thursday, November 06, 2014 8:13 PM
To: collins@xxxxxxxxxxxxx
Subject: {Collins} KWS-1, Up & Running----700 Watts+ Output on 75 Meters

Hello the Group:


I bought my KWS-1 serial number 700 almost one year ago.  Many distractions
interfered with the rapid restoration I had originally envisioned.  I had
several occasions where I asked for support from the group and every time I
received many valuable suggestions & hints.  I want to let the group know
that now the KWS-1 is running fine, with 704 watts output on 75 meters.


I must admit I made a mistake or two during the restoration process.  I will
condense the following comments, to avoid too much embarrassment!  


My latest posting was about no PTO output.  I thought I had no PTO signal.
That was my own error, the PTO was working perfectly.  


So, what is next?  I had not enough drive to show grid current on the
finals, so I decided to perform the initial alignment steps per the manual,
all focusing on the 80 meter band.  


I have some decent equipment to perform this activity, consisting of a brand
new Rigol 1102E 100 MHz scope, a HP 410B RF Voltmeter, and some Fluke DVM's.
I have the standard VTVM's all collecting dust but ready work as required!


I soon discovered I had no significant drive arriving at the grids of the
6CL6 drivers.  I simply plugged a BNC cable into the grid jack and measured
what was present using the scope.  OK, so I followed the manual, step by
step and produced a dramatic change when I was dealing with L201, part of
the alignment steps associated with the 1st mixer, V201 a 12AT7.  Now as you
read this, keep in mind I had 608 watts output, for 3-4 days then it
disappeared.  I adjusted L201 and the grid current went up dramatically, so
at this point I have enough drive to share with others!  I originally NEVER
saw grid current on the 4CX250B's.  I believe the issue was present when I
purchased the radio.  How I saw 608 watts on the wattmeter will remain a
point for future discussion, not sure what happened to allow that anomaly!


I set up this afternoon, turned on the 75A-4 and KWS-1 and let them warm up.
Everything was ready to test.  I found the 75 meter group I was hoping to
visit with, then zero beated the KWS-1 against the 75A-4.  Tuned up off
frequency and all went well.  Achieved 704 watts output, on my LP-100A
wattmeter.  I checked into the gathering, but the group did mention they
could hear a hum on the mike, when I stopped talking.  Was seeing 692-704+
watts output the entire time.


Another interesting item, was the date coding I found.  Please review the
Care and Feeding article, that has been so helpful to all of us.  There is a
reference to serial numbers and when a particular KWS-1 was manufactured.
The chart suggests that my rig, serial number 700, would have been built
during the summer of 1956.  I feel that is very accurate, since I have a
dead 20 meter 11.00 MHz crystal.  Today I ordered a replacement, but first
pulled the original crystal out and made sure the lead diameter matched what
I was ordering.  On the bottom of the dead crystal in red ink was stamped


That date code seems to match very well with the data available in the Care
and Feeding document!  Thank You Bill Carns!!


I owe a big Thank You to the many individuals who offered support and their
knowledge on a regular basis.  That plus my own persistence allowed me to be
successful in getting this 1956 jewel back on the air.  Another Thanks to my
friend who sold me a group of six 4CX250B's for $5 each, all good.  Um, I
will report on that topic by Christmas!


Now to track down that microphone hum-----


Best Regards to All,


Chuck Curran  W9KR

Cedarburg, WI

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