I have two KWM2 and one with the rejection tuning.
The power supplies are PM2 and i use the nice 312B-4.
I have Two 32S3. The first from 1970 ( SN: 101491) and the second between 1970 and 1971 ?? (SN: 101782 and MCN 1716).
Power supply are 516F2 and PM2.
A great receiver !
Some ideas to restore a Collins 30L1 (compiled from F6HOY/F6CER/F1LAG) :
Big brother with 4CX1000A
Tuning Collins 30S-1
Bring the amplifier on line and let it warm up until the HV lamp and HV will come on.
1. Start with the mic gain turned all the way down
- Select the band of interest on the 30S-1
- Preset the tuning control to the center of the band segment indicated on the lower (difficult to see) part of the dial disk below the logging scale
- Set the 30S-1 load control almost all the way to the left (CCW – low numbers)
- Place the multimeter switch in the Control Grid Position (Grid Current) & monitor closely during tuning
- Go back and forth between Grid Current and Screen Current.
- Allow no Grid Current – Ever
b. Try to keep Screen Current under 10 mA –
I usually see almost none.
- Select Lock Key with the driving rig (You can start with the Tune position, but this is not necessary if the driver is already tuned and you are careful).
- Increase the mic gain (carrier control) until you get some indication of 30S-1 plate current rise.
- Immediately dip the 30S-1 Plate Tuning.
- Increase the amp loading. The plate current should rise and then quickly redip the plate current. You should be seeing some power output.
- Repeat steps 8 thru 10 until you reach 350-400 mA of plate current dipped on the 30S-1.
- Reduce the drive to get 300-350 mA of plate current.
Leave the Loading & Tuning where they were.
- Give the amp a break and let it cool taking the driver out of Lock Key.
Leave the Mic Gain set where it is.
Select the correct sideband on the driver.
- You should have seen over 6 dB of ALC indication on the driving rig meter with it set to ALC position. Now, in normal SSB operation, you should see about 6 dB (32S series) or S6 reading on the KWM-1/2 series on voice peaks.
You should increase the mic gain slightly (only if you need to) to get these ALC readings.
Inside 30S1 when i get it…