Merry Christmas everyone,

I just got this radio, it is in beatiful condition. The clock is in perfect condition. I removed the chassis and bypassed the clock to power the radio. Ths radio plays but has static across the tuning range. It will bring in stations. I want to service this radio but not make initial mistakes that could cause me heart burn later.
The volume control is lose and needs to be lubed/cleaned. What should i use to clean.
As far as i can tell the 50C5 and one paper cap has been replaced.
Please advise on initial steps to start on the repair/service.
Best to all
Mitch

If this is a crashing type of static, check C8D and C17 for arcing under high voltage (use capacitor analyzer with high voltage leakage test or substitute with new capacitor). Also check IF transformers for silvered mica capacitor corrosion. This can't usually be seen, but if you rock the IF transformers, sometimes this will affect reception and affect the crashing sounds. If there is arcing from the capacitor on the primary coil to the capacitor on the secondary coil, you may see voltage fluctuations either on the plate side of the primary coil, or on the grid (or detector plate) side of the secondary coil.

If you cannot peak the IF transformers well, or reception is poor, then the mica capacitors inside have likely gone bad. Also, if you have a good capacitor analyzer with high voltage leakage tests, you can disconnect the coils of the transformers and measure the capacitances of the capacitors, and also check the capacitors for arcing and leakage amongst themselves and between each other.

First check the discrete capacitors and/or replace paper capacitors that are across high voltage potentials. Also check and/or replace any square mica-looking capacitor in the audio circuit that is across high potential, as these are often actually paper, and develop arcs within (such as C8D). Ceramic capacitors rarely fail, and should not normally be replaced, though you can try substituting new capacitors if you cannot otherwise locate trouble.

...Then, if replacing discrete capacitors in common trouble spots doesn't rectify the problem, you will likely have to dive into the tedious job of replacing the capacitors within the IF transformers.

Also, be sure to check resistors for internal arcing, which can cause static and crashing noises. This is uncommon, but does occur occasionally.

If the static only occurs as you rotate the tuning capacitor, then there might be shorts between the plates.

If the radio otherwise has the normal buzz type of static, check to see if it is on any of your other radios, and if there is anything you can do to this radio to filter it out, or try unplugging devices around your home such as battery chargers and power packs, as these produce a lot of interference.

:If this is a crashing type of static, check C8D and C17 for arcing under high voltage (use capacitor analyzer with high voltage leakage test or substitute with new capacitor). Also check IF transformers for silvered mica capacitor corrosion. This can't usually be seen, but if you rock the IF transformers, sometimes this will affect reception and affect the crashing sounds. If there is arcing from the capacitor on the primary coil to the capacitor on the secondary coil, you may see voltage fluctuations either on the plate side of the primary coil, or on the grid (or detector plate) side of the secondary coil.
:
:If you cannot peak the IF transformers well, or reception is poor, then the mica capacitors inside have likely gone bad. Also, if you have a good capacitor analyzer with high voltage leakage tests, you can disconnect the coils of the transformers and measure the capacitances of the capacitors, and also check the capacitors for arcing and leakage amongst themselves and between each other.
:
:First check the discrete capacitors and/or replace paper capacitors that are across high voltage potentials. Also check and/or replace any square mica-looking capacitor in the audio circuit that is across high potential, as these are often actually paper, and develop arcs within (such as C8D). Ceramic capacitors rarely fail, and should not normally be replaced, though you can try substituting new capacitors if you cannot otherwise locate trouble.
:
:...Then, if replacing discrete capacitors in common trouble spots doesn't rectify the problem, you will likely have to dive into the tedious job of replacing the capacitors within the IF transformers.
:
:Also, be sure to check resistors for internal arcing, which can cause static and crashing noises. This is uncommon, but does occur occasionally.
:
:If the static only occurs as you rotate the tuning capacitor, then there might be shorts between the plates.
:
:If the radio otherwise has the normal buzz type of static, check to see if it is on any of your other radios, and if there is anything you can do to this radio to filter it out, or try unplugging devices around your home such as battery chargers and power packs, as these produce a lot of interference.
:
Thank you,
I will make these checks. I do have a rf and af generator to make the alignment checks. There is no Hummmmmm as per 60 Hz. It is a static across the tuning range and gets louder with the volume control. I can tune in afew stations.
Would i be correct to think that capacitors are the main cause of static?
Thanks
Mitch

Check the antenna loop connections. There is an external antenna provision. Often the connections can be wrong, due to someone guessing where they go. Also test for continuity of the main loop. Static can be caused by no return, and poor reception.

:Check the antenna loop connections. There is an external antenna provision. Often the connections can be wrong, due to someone guessing where they go. Also test for continuity of the main loop. Static can be caused by no return, and poor reception.
:
Warren,
You must have looked at the schematic. The loop antenna reads 2.2 ohms for continuity. You may have found my problem but want to confirm the connections before i power the radio up again.
I have three wires coming out of the back of the radio. A yellow wire coming from C1A was connected to the Ext. Ant. connection, a red wire was connected to to C1A and the loop of the antenna, a black wire coming from C10 and C01 was connected to the loop antenna.
I think that the two wires (yellow and red From C1A) should go to the loop antenna and the black wire should go to the Ext. Ant. connection.
All thoughts on this before i make the change and power up again.
Thanks
Mitch

Is this a crashing crackling sputtering type of static, or does it contain some hum? Crashing static (like when lightning strikes) is usually caused by a faulty part within the radio that is either arcing over or is making poor connection. If you can turn the static down, then it is likely occurring before the volume control in the RF section. This could be silver mica capacitor failure within the IF transformers, or it may be something else.

If there is merely a lot of interference not of the crashing kind, then you may have a poor antenna connection as Warren suggested, or some other trouble.

T.

:Is this a crashing crackling sputtering type of static, or does it contain some hum? Crashing static (like when lightning strikes) is usually caused by a faulty part within the radio that is either arcing over or is making poor connection. If you can turn the static down, then it is likely occurring before the volume control in the RF section. This could be silver mica capacitor failure within the IF transformers, or it may be something else.
:
:If there is merely a lot of interference not of the crashing kind, then you may have a poor antenna connection as Warren suggested, or some other trouble.
:
:T.
:
T,
Please read my thread about the antenna wiring. I think i received the radio with the antenna wired wrong. Need it confirmed.
Thanks

From what you are saying the connections are wrong. Make the correct connections as shown by the schematic. I would bet that's the problem alright.

:From what you are saying the connections are wrong. Make the correct connections as shown by the schematic. I would bet that's the problem alright.
:
I connected the antenna according to the schematic and cleaned the radio/phono switch. The radio can pick up stations and hold them now without the reception static.
I can now hear the low 60 Hz hum. There must be some bad caps as there is a crackle/pop background noise with or without a station tuned in.
Your thoughs?
Mitch

You do need to replace all the old paper capacitors and the filter capacitors as well. That crackle and pop noise is more than likely the silver migration problem inside the IF cans. C3 C4 C6 C7 .. Here is a link showing how to repair the IF cans with pictures. Scroll about 3/4 down the page.

http://www.wa2ise.com/radios/repair.htm#if

Be sure to mark with a felt pen the location of the IF can pins to the chassis. So you don't get the primary and secondary reversed, when putting it back together.

:You do need to replace all the old paper capacitors and the filter capacitors as well. That crackle and pop noise is more than likely the silver migration problem inside the IF cans. C3 C4 C6 C7 .. Here is a link showing how to repair the IF cans with pictures. Scroll about 3/4 down the page.
:
:http://www.wa2ise.com/radios/repair.htm#if
:
:Be sure to mark with a felt pen the location of the IF can pins to the chassis. So you don't get the primary and secondary reversed, when putting it back together.
:
:
I book marked the site. If i am unable to repair the IF can's is there some place i can get new or refurbished ones. I will try but i am almost blind and fear that i won't be able to see the problem or if there are small wires i won't be able to see them and make mistakes or damage them.
Thank you
Mitch

::You do need to replace all the old paper capacitors and the filter capacitors as well. That crackle and pop noise is more than likely the silver migration problem inside the IF cans. C3 C4 C6 C7 .. Here is a link showing how to repair the IF cans with pictures. Scroll about 3/4 down the page.
::
::http://www.wa2ise.com/radios/repair.htm#if
::
::Be sure to mark with a felt pen the location of the IF can pins to the chassis. So you don't get the primary and secondary reversed, when putting it back together.
::
::
:I book marked the site. If i am unable to repair the IF can's is there some place i can get new or refurbished ones. I will try but i am almost blind and fear that i won't be able to see the problem or if there are small wires i won't be able to see them and make mistakes or damage them.
:Thank you
:Mitch
:
Another site for silver mica.
/www.ppinyot.com/if_transformers.htm
Mitch

Is this a crackling sound like what arcing would sound like in the speaker or is it just interference? Can you hear this noise in your other radios as well? If so, then there's nothing wrong with the radio. If it sounds like arcing, then there is trouble within the set. You should not rebuild the IF transformers unless you need to. This is a tedious and risky job. If they are in fact working well, you can inject dielectric grease into the capacitor area to protect against future corrosion.

T.

Rebuilding those IF cans is a tedious job. Does require a good look at what you are doing. If you would like to send both cans to me, I will rebuild them for you. Be sure to mark the cans 1st & 2nd IF. Make a drawing of the wire connections, or/and take a close up picture. Also mark the bottom of the can to a mark made on the chassis. So you put them back in the way they came out. The radio will need alignment of course afterward.

:Rebuilding those IF cans is a tedious job. Does require a good look at what you are doing. If you would like to send both cans to me, I will rebuild them for you. Be sure to mark the cans 1st & 2nd IF. Make a drawing of the wire connections, or/and take a close up picture. Also mark the bottom of the can to a mark made on the chassis. So you put them back in the way they came out. The radio will need alignment of course afterward.
:
Warren,
Check email.
Bless you for the help.
Mitch