I cleaned switch A & B and the bandswitch carefully with contact cleaner. Just didn't hose it down, squirted individual points just a little, using Q-tips.
Checked voltages on the tubes. 6A8G was a little low. I know resistors 17 & 32 were a little high (1270K & 1190K respectively vs 1Meg).
Trying to find why AM reception is so bad. Any suggestions?
Hello Morzh - not yet. I was rechecking coils and switch connections first. I don't have the signal gen and other equipment to do a proper alignment. If I eliminate other issues, might have to buy the E stuff. I'll submit a marked up schematic later.
>> I don't have the signal gen and other equipment to do a proper alignment.
There are workarounds. Some folks here are good at it.
Still, if you are serious about continuing in this hobby, a few things, of which a generator is one of, are very desirable.
Before you align the radio, there is no telling if your woes are due to other things or due to simple misalignment.
People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
>> Somebody added one on my Philco 37-60B. Doesn't show up on the schematic. Afraid to try it out.
Use a modern DMM, measure the AC voltage relative to the GND (chassis) on both input sockets.
Then measure DC. If the DC is significant, put 1MOhm resistor across and re-measure. If it is small (should be on an order of a volt or lower), you do not have to be afraid of using it.
People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
Admin - I was trying to just state that phono inputs are added as an option and don't show up on normal schematics. Wasn't trying to extend my post, just using mine as an example. Afraid to try it out wasn't meant as a question, it's a statement.
Reckon option was the wrong wording. Wasn't trying to imply it came from the factory like that. I was trying to state it as I did originally, "somebody added one on mine".
I'm not a hobbyist, I'm not an electronics wizard. Just wanting to get my father's radio working like I remembered it. I don't collect radios and fix them up. I don't have signal generators & scopes.
Would be nice if people could jump in and give basic advice that a novice could understand. Seems like you get enough quick responses when you mess up formalities.
I apologize for the strongly worded post, but it really did sound like you were trying to say your phono jack was installed on your radio from the factory. I assure you, it wasn't.
And if you go back and look at the previous posts in this thread, you will see that many people have been trying to give sound advice here. However, there is no substitute for learning the basics of electronic repair on your own, and there are many sources to learn the basics. One of the best may be found here:
I have a long 15ft wire on antenna terminal 1. Strung near the ceiling of my room. 2&3 are jumpered. 3 is grounded by a single 12 AWG wire to socket ground, same socket 2 prong plug is in.
Speaker is sitting separate about 3 ft from the radio. Doesn't have the tin shield box on it. Would not fit the new output transformer.
Have a shield on 6Q7Gtube. Shield wouldn't fit on the 6K7G tube. Tube too wide at top.
Replaced all electrolytic caps and paper caps. Replaced most resistors per previous posts.
Voltages seem okay except 6A8G, it's a little low.
Presently shortwave is better than AM, but I can only pick up strong shortwave at night with clear voices/music. SW during the day is weak. AM is nonexistent during night and day. Can barely hear a few positions where AM stations are. A lot of background noise, white static. I have checked the resistances of coils as shown on schematic a 2nd time. Did this before. I have not checked any mica caps
Have not done any alignment yet, don't have a sig gen or oscilloscope, just a DMM.
Is there a switch with the phono connection? Is it an "RCA Jack?"
If you can, post a pic of the jack and the underside of the chassis. Although Philco did not put phono or "phono - television" jacks on this radio, it was not uncommon to have a Radio Shop install one back in the day, either from a kit (RCA sold a neat one) or individual parts. Some had a switch, some relied on the user to tune the radio to a dead section of the band.
+1 on Morzh's comments. The phono input is usually isolated from any voltage by a capacitor of approximately 0.1uF. Sometimes, this is added, but most of the time, the mod uses the cap between the center (wiper terminal) for the volume control and the grid of the first audio tube (a 6Q7 in your case).
In troubleshooting radios, if it has a phono jack, I will use it to inject an audio signal from the computer, a CD or MP3 Player, etc. If the phono connection is the RCA type yu can get a 3.5mm TRS to twin RCA adapter cable) It would have 2 RCA plugs because the MP3 / computer / CD Player is stereo. For teting purposes, you can use just 1 of the 2 RCA plugs. You will be missing a channel but it willbe good for testing.
'If you can't get good, clear, loud audio from using the phone jack to inject a signal, then you have a problem with the 1st Audio or "Power Amp" circuits. Alignment will not solve this. The Audio circuit is relatively simple.
Was the short wave station nice and loud or barely heard? Are you in the basement? How is AM reception on another radio in the same location? Are you urban, suburban or rural? This is a common, transformer powered version of the "All American Five" 5 tube radio circuit. The AA5 term usually applies to transformerless sets whose B+ is usually in the order of 100V. These sets do perform rather well. The same style tubes with 200 -250V Plate circuits perform even better.
I practically cannot run an AM radio in my house (what with all of the computer, LCD, WiFi, LED lights, etc., unless it has a "ferrite stick" type antenna. Somehow, ferrite stick antennas seem to be less susceptible to RFI. (Radio Frequency Interference). Try turning off ALL computers and monitors, cable modems, unplug all LCD TVs, turn off all LED and Fluorescent lights. Also, try to use a longer wire, say 50 Ft, run from the house to a tree, "pointing" to the direction of the stations.
I live in suburban NY, served by at least 5 Clear channel 50KW stations, and many others. In the past 10 years, it has become almost impossible to listen to AM, even in any of our 3 cars.
One trick would be to touch the antenna wire directly to the metal "grid cap" on top of the 6A8 tube and try to tune broadcast stations. If you pick up more stations than when the antenna is connected to the correct terminal, then there is an issue with either the Antenna coil or the band switch.
Hope this all helps. Keep on trying and you will succeed. Keep on posting and we will help. When you get this one working, find another and fix it! For a non-antique radio hobbyist, you have done really well so far!
Best regards,
MrFixr55
"Do Justly, love Mercy and walk humbly with your God"- Micah 6:8
Best Regards,
MrFixr55
(This post was last modified: 06-24-2023, 09:12 PM by MrFixr55.)
Yep, has an RCA connector and a switch. I'll try it out with my modern turntable.
In the evenings I get about 4 shortwave stations. 2 come in pretty loud. Hardly get any AM stations Very faint, can barely hear voices over the background noise. I'm in the country, rural SC. Got the radio in a shed I converted into an 20 ft long office (power, sheetrock, insulation). About 150 ft from the house. Running a single 15ft wire from antenna terminal 1. 2-3 bridged with 3 connected to socket ground.
I'll try the antenna wire on the tube. We'll see. Appreciate the support.
