[winkydink]

I am going to combine 2 newbie questions into 1 post

I just got back a 42-PT95 from a recapp job. I still have 2 issues with the radio

1) When turning the radio on, and moving the volume control I get loud static. Additionally, lowest volume setting of the radio is moderately loud, then if I can get past the static, further up on the volume control it is softer, and then gets louder again.

Q: Is this just dirt ? How can I clean the volume control (Contact Cleaner). Link to proceedures if possible. Why is it loud, the softer, then loud again ?


2) The pointer to the tuner works, but is not pointing to the proper frequency. How can I correct this ?

Thanks again for the valuable information.

-Jim

[codefox1]

Yuppo. Clean the control move the pointer. Then come back.

[TA Forbes]

The pointer can be adjusted manually, move it to correct location on a known good station.

[winkydink]

TA

Do I just twist the pointer to the proper frequency or do I have to pop off the pointer and put it back on.

I have tried to look around on this topic but did not see anything obvious.

Thanks.

[TA Forbes]

Either or. Have not had this specific model but from looking at it I believe you should be able to just twist it.

[winkydink]

New question about volume control:

I have taken the chassis out of the cabinet and used tuner cleaner, multiple times but the volume control is still static/noisey when first turned on and softer end of the volume.

Do these go bad ? Is my only recourse at this point to un-solder remove, and put in a new/replacement volume control ?

I do have a 42-PT94 junker, but don't really know if that volume control is any better.

Anyone know of a "dummies" guide to cleaning volume controls ?

[TA Forbes]

Yes, they do go bad. The volume control is a .5 meg according to the schematic. Measure the one you have, it should taper evenly from near zero ohms to .5meg. Also measure the one that you have in your parts chassis and go from there.

It should be fairly easy to find a nos or new replacement for your volume control if both of the ones you have are unsat.

Mark Oppat at www.oldradoparts.net has many nos controls.

[morzh]

What happens often times is this: closer to the beginning of the element, at its left side, where the volume is supposed to be low, there develops a rubb-through, so instead of the encountering the low resistance, the wiper encounters very high to infinite resistance, so no attenuation occurs and the volume gets loud. Then you rotate it a bit further and the wiper hits the conductive area, and so the voluime gets down, and then is rising as you keep moving the wiper towartds the right side (maximum volume).

Some people suggest rubbing the bald spot with the pensil. I think it is a palliative and won 't hold for long, but may work short-term. Especially if you treat it with Deoxit, that will luibriocate it and stop the wiper from taking that graphite of quickly.

[winkydink]

Here are the on/off volume controls from a 42-PT95 (smaller) and a 1947 Philco with the same chassis (larger).

The back 2 connectors. Are they interchangable ? Since the layout of the 2 controls are slightly different, I want to make sure before I re-wire the new volume control, and not short somthing out.

Thanks.

[Steve Davis]

The physical size of the control does not make any difference. If the value of the control is close to the original you are go to go. You can check it with an ohm meter, where there are three terminals take, your reading between the two outside ones.

Steve

[winkydink]

A small small victory for me. It seems lately everything that I have been attempting to do with the radios I am working on has backfired or gone awry. I managed to re-install the 1947 switch into the 1942 radio and it worked with no static. I still need to properly re-solder the antenna leads back on, but finally something that worked.

I will quit today while I am ahead !

[winkydink]

Reattached the antenna today. It works !

I know this sounds silly to those of you with much experience, but for me, this is the first thing that has gone right [with regard to radio repairs] in over a week.

I am thrilled. I straightend the grill with a heat gun, and also install a new plastic dial cover. I will put it together later today, and post pictures.

I may have to dremmel off some excess lenght of the volume control shaft, but I will see after I have the radio back into the cabinet.

[winkydink]

Well ..... I spoke too soon.

I think the switch from the '47 Philco is also defective/dirty.

The volume is not as loud as it was before, but if I press on the volume stem it becomes loud. Also the radio has a slight buzz when the volume is turned up [no buzz when the volume is low].

So as it is right now, it is unacceptable. I guess I will check for loose connections. I had already cleaned the control with an electrontics contact cleaner after I took it out of the '47 radio (before the intall into the '42 radio).

**** Any opinions, or things I can try or look for ? *****

I do have another new switch on order from Mark Oppat, but it has not arrived yet. I guess I will fire off another email. So close [I think] ...