Lafayette Comstat 23 Issue

[Raccoon]

Ok .... so recently I was talking away on my Comstat 23 , and it was preforming well .

Then after about an hour or so , I was being told that when I'd first key it up it was sounding odd . Not transmitting , sounding scratchy . But then after a few seconds it would clear up and start sounding good again .

How would you diagnose that issue ? Because I have no idea where to even start looking to track that down .

 

[Shadetree Mechanic]

How long have you had the radio, and have the capacitors been replaced? It sounds to be a capacitor problem if they are original.

 

[nomadradio]

A radio that old represents a long list of possible faults.

I would start with a can of non-residue contact cleaner like CRC-brand "QD" found at Autozone and other places.

Pull each tube, one by one and spray the socket contacts. Plug the tube back in and work it in and out a few times before the solvent evaporates.

When you have cleaned them all, you should be able to (gently) push the top of each tube slightly from side to side without hearing any scratch noises or such. If you do, lather,rinse,repeat that tube.

Likewise, a "flick" of a fingertip to the side of each tube should not trigger any noises in the receiver. Hold the tip of the tube in place while trying this. A tube that makes noises when it's tapped on the side has a structural problem inside, and becomes a prime candidate to cause an intermittent fault.

Could be other troubles besides this, like capacitors that are decades past their use-by dates. But purely mechanical issues like noisy controls and tube sockets are incredibly common faults to encounter.

73

 

[Raccoon]

How long have you had the radio, and have the capacitors been replaced? It sounds to be a capacitor problem if they are original.

Shadetree , I bought the Comstat 23 in May . It has been recapped , but I'm not sure how long ago . Here's a pic of it's bottom side , showing the caps that are in it .

A radio that old represents a long list of possible faults.

I would start with a can of non-residue contact cleaner like CRC-brand "QD" found at Autozone and other places.

Pull each tube, one by one and spray the socket contacts. Plug the tube back in and work it in and out a few times before the solvent evaporates.

When you have cleaned them all, you should be able to (gently) push the top of each tube slightly from side to side without hearing any scratch noises or such. If you do, lather,rinse,repeat that tube.

Likewise, a "flick" of a fingertip to the side of each tube should not trigger any noises in the receiver. Hold the tip of the tube in place while trying this. A tube that makes noises when it's tapped on the side has a structural problem inside, and becomes a prime candidate to cause an intermittent fault.

Could be other troubles besides this, like capacitors that are decades past their use-by dates. But purely mechanical issues like noisy controls and tube sockets are incredibly common faults to encounter.

nomadradio , I have a can of that contact cleaner .... so I'll give that a try , and see how that goes .... thanks

 

[midnight special]

i would suspect the keying relay might be dirty,,,,,,

 

[Raccoon]

So tonight I wired my Lafayette 99-4607 desk top mic to my Comstat 23 , and I took nomadradio's advice and removed the tubes one at a time and sprayed the tube sockets with contact cleaner . I also cleaned the contacts on the 99-4607 mic , and "So Far" everything "Seems" to be sounding good. So I'll keep my fingers crossed and hope that this continues .

If it does it again , then I'm going to take midnight special's advice next ... and check out the keying relay .

thanks everyone