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Author Topic: Exciter tuning knob question 32S-3  (Read 2524 times)
W5INC
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Posts: 38




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« on: June 17, 2012, 10:11:01 AM »

 I am working on my RE S Line trying to track down a intermittent problem with the Xmtr. I took the mounting bar off, for the 3 RCA plugs that sits right behind the exciter tuning knob, which comes off with 2 screws. I needed to check the RCA plugs mounted on the bar because the cables were sitting very loose in the jacks. When putting the bar back on to it's mounting pads, I discovered that the inner knob for the exciter tuning will turn but the outside pointer does not.  Huh I don't think I moved the inner knob at all during this process. The exciter tuning worked before I took off the mounting bar for the 3 RCA plugs. It looks like the exciter control is a 2 piece guy with an inner and outer shafts for tuning the exciter. Collins use of the RCA jacks for all of the interconnecting cabling for their S Line/KWM-2 units is suspect at best, IMO. I am new to working on these units and need to ask the more astute members of this Forum for any insights they might have concerning this problem.  Smiley
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WD8AJY
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« Reply #1 on: June 17, 2012, 10:57:56 AM »

try losing the screws and pull the to end plates together and tighten the two screws. 73 Wd8ajy 
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W5INC
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Posts: 38




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« Reply #2 on: June 17, 2012, 01:09:41 PM »

try losing the screws and pull the to end plates together and tighten the two screws. 73 Wd8ajy  

 TNX for the information there WD8AJY. The tuning shaft looks to have a tension adjustment on the very back of the shaft that uses the end mounting tab, threaded rod and nut to get the desired tension needed. The exciter adjustment was never very good anyway, so it will now be taken care of, I hope.  Cheesy You would have to have very large hands to be able to squeeze the mounting ears of the shaft together and still tighten the screws down, that hold everything in place. These screws were torqued down fairly well, now I can see why.  Wink

 http://i1241.photobucket.com/albums/gg505/w5inc/Collins002.jpg
  
 There is a ball bearing setup on the front end of the tuning shaft. Nice touch by the Collins factory to allow smooth tuning of the exciter. The ball bearings look to ride on a "bearing race" created by the front mounting tab. This is where the correct tension on the tuning shaft comes into play. The bearings have to be in the "race" created by the front mounting tab in order for the tuning shaft work properly, I am thinking.

http://i1241.photobucket.com/albums/gg505/w5inc/Collins001.jpg


 
« Last Edit: June 17, 2012, 01:33:22 PM by W5INC » Logged
W5INC
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Posts: 38




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« Reply #3 on: June 19, 2012, 10:08:22 AM »

try losing the screws and pull the to end plates together and tighten the two screws. 73 Wd8ajy 

 Had some free time today because of the rain here in Houston today. I got a padded clamp that I could apply the proper tension on the tuning shaft to get the ball bearings to seat properly in the front mounting tab. I didn't tinker with any of the previous settings on the tuning bar and just added the clamp to get everything back in working order.  Smiley

http://i1241.photobucket.com/albums/gg505/w5inc/Collins004.jpg


 I still have the intermittent Xmtr problem. The PA tubes have the proper bias voltage and cap voltage. The bias is set @ 40 ma and the PA cap voltage when in receive is right @ 980 volts. So the PS is working properly. On Saturday night I had the Xmtr working and made a VK2 contact. I left the radios on all night and when getting up on Sunday morning the Xmtr no longer worked.  Huh So I separated the units and have the Xmtr running by itself into a dummy load. I still have the proper voltages to the PA tubes. With no mic gain adjustment to be had in the tune up procedure, I will be checking the 1 and 2nd audio amp circuits next. It could be 1 of the 6UA8s is bad.  TNX agn WD8AJY for your help. Smiley
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WD8AJY
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Posts: 60




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« Reply #4 on: June 22, 2012, 08:58:18 AM »

I have an 32S3 that will not tune up unless the mic gain is all the way up. then i can turn it down to about the 10 o'clock position  on the air. 73 Bob.
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KE5OWY
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Posts: 5




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« Reply #5 on: June 22, 2012, 11:25:05 AM »

When I first got my 32S3 and 75S-3C, I decided to revamp all the interconnecting cables.  I used some Belden mini coax and it all looked great.  When I tried to load up the xmitter, things were weird.  Some bands would load, others wouldn't.  Parts of a band might be OK, other parts not.  When I separated the receiver and transmitter (removed the two transceive cables), the transmitter worked fine.  I made new transceive cables out of RG-58, 4 feet each, hooked up, and it worked beautifully.  The system did not like the two new transceive cables I had made out of mini coax!!  Perhaps something to check.

William
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W5INC
Member

Posts: 38




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« Reply #6 on: June 25, 2012, 08:07:29 AM »

 Thanks William and ADY for the suggestions on repairing this S line. I had everything apart Friday night and found what seemed to be a loose RCA plug in the rec. for the oscillator output. Put everything back together outside the cabinets and the units worked Friday night with no problems. When loading up the grid current it was shaky at 1st, but the 32S-3 did finally load up. Saturday morning came and I put both units back in their cabinets and hooked all cables back up for Field Day. Turned on the units and I had no Xmtr once more. Sad

 Since I wanted to work Field Day, I pulled out a last production run 1000D, that has been sitting in my closet for years and fired this guy up for the 1st time. I have no way of checking the tubes in the 32S-3, so I will be looking for a TV-7 tube testing unit or another model that Hickok made. Some of these Hickok tube testing units still go for big money, so I will look around for a good deal on 1. TNX once again to the members here who answered my post here in this Forum.  Wink
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WD8AJY
Member

Posts: 60




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« Reply #7 on: June 25, 2012, 08:48:03 AM »

here is another thing i had to do to a 32s3 on J2 the Rec xtal osc input there is a resistor r141 and a capacitor i disconnected the resistor from J2 this worked for me. 73 Bob 
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