My First Philco Radio

Sorry, I had forgotten which tube was switched .Is the 7B7 the weak one?

yes, the 7B7 was the weak one. Interestingly enough though the radio doesn't seem to be making any oscillation noises which I'm not sure if that's a good thing or a bad thing, because I remember you saying that if that capacitor/choke combo piece wasn't constructed properly it would make the radio "howl" or oscillate unbcontrollably and it doesn't seem to be doing that unless that weird "beating" noise its doing had something to do with that choke on the capacitor that I redid on the new capacitor when I removed the old one.

I swapped out the old 7B7 for the spare 7C7 tube I had laying around and it didn't make much of a difference except that the "beating" sound that it does starts later up on the volume controller scale than it did before (before I swapped the tube out the "beating" sound was starting with the volume control near the minimum setting and now it starts with the volume control at the half way setting and goes up from there.)
 
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I'm working Days for the next 6 weeks. Have you measured resistances around the new IF transformer?You could check voltages according to the chart for the whole radio. You could try a longer antenna to see if you can pick up anything.With out an o-scope this is getting harder. If every thing checks out, with the longer antenna,you could carefully adjust the adjustment screws on the new IF transformer. Remember exactly where they are,and move them a little one way,then the other way,and if it doesn't help move it back. I'll be on break at 8 Am
 
I would have to go back and re read the thread, But I think someone else talked about the cap and choke.I don't remember saying it.
 
I'm sorry.I didn't post clearly

between pin 6 of the 7B7 and pin 4 of the 7C7
between pin 6 of the 7A8 and pin 4 of the 7C7

between pin 6 of the 7C6 and the volume control where it meets C21 reading is supposed to be ~47k

So I retested all of these areas with my multimeter set to the ohms setting, and I got between pin 6 of the 7B7 and pin 4 of the 7C7 about 23.5 Ohms and between pin 6 of the 7A8 and pin 4 of the 7C7 about 30.0 Ohms and then here's the real stumper from pin 6 of the 7C6 to the volume control/C21 connection I still get an open reading, even though its a different I-F Transformer.

The only thing I can think of that might of happened is that when I first got the I-F Transformer it had a cardboard "Bushing" on the bottom of the transformer that was used to keep the wires going into the transformer seperate and when I was trying to pull that cardboard "bushing" off the bottom of the transformer I accidentally pulled the core off of the capacitor head and yanked the wire leads off with it so I tried my best to resolder the wire leads back on which I may or may not of wired them to the right terminals but it was kind of hard to tell where they went when I didn't even have a good look at where the wires went to begin with and I didn't have a good reference to begin with as to where each of the wire leads was supposed to go.
But other than that I shouldn't be having issues with my new I-F Transformer because then that would mean that obviously Philco didn't have a very good record of making good I-F Transformers and that means that basically any Philco from that time period I run into is gonna have the same problem which I would hate for that to be the case because then if someone comes along and wants me to fix their grandfather's old Philco for them I would have to tell them it wouldn't be worth fixing because it has a bad Secondary I-F Transformer and that was a very common occurance with these old Philcos and its nearly impossible to find a good replacement...

Are you sure I was supposed to measure pin 6 of the 7C6 to the volume control? because to me that doesn't seem right and I can't get any measurements there not even with the new I-F Transformer in place and like I said unless Philco was known for having faulty I-F Transformers in their radios back then it shouldn't be possible for 2 Philco I-F Transformers to measure opened like that and at that 2 I-F Transformers from the same type of radio from the same era from the same company.

Unless like you said before the volume control might be bad or might need cleaning...

Any other ideas?
 
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It seems like the B-/Floating Ground is fluctuating because when I was taking voltage readings my multimeter would be giving me erratic readings where the readout would flicker really fast and would be giving me a reading but when it would flicker it would be flickering between volts and millivolts at the same time and what's weird is that even after my multimeter was removed from the circuit I was testing that was giving me the funky readings the multimeter would still be flickering and giving funky readouts until I touched the leads together and then it would calm down and zero itself out.
Is it possible that there might be a phantom in my household wiring that's causing the erratic operation?
I'm asking because my house is an 60+ year old house with most of its original wiring (cloth covered rubber sheathed romex from the 1930s without a ground but yet there's grounded outlets that are grounded to the box) and I'm wondering if that could be affecting my readouts?
 
I doubt it's house wiring, The meter is auto ranging,so when there is varying voltages it will try to give a steady reading,when the leads are disconnected it'll go to it's most sensitive setting, even touching the leads will with your hand will give a reading,picking up the noise in the in the "air"
Can you measure between the white and green leads of the new transformer, it should read 47K. Does the meter have a battery level indicator, sometimes a low battery will give strange readings
 
I doubt it's house wiring, The meter is auto ranging,so when there is varying voltages it will try to give a steady reading,when the leads are disconnected it'll go to it's most sensitive setting, even touching the leads will with your hand will give a reading,picking up the noise in the in the "air"
Can you measure between the white and green leads of the new transformer, it should read 47K. Does the meter have a battery level indicator, sometimes a low battery will give strange readings

Battery is fine, the battery low display isn't showing up yet. As for trying to measure between the green and white lead, I really would prefer not to try and take this transformer apart again because I had a really hard time getting it put together in the first place. but measuring between the white wires and pin 6 on the 7C6 does give me 2.3 Meg which is what R12 is reading (R12 is a 2.2 Meg Resistor.)
 
Can you find where the green and white wires connect under the Chassis?
It still looks open, Did you measure the transformer when you received it?
 
Can you find where the green and white wires connect under the Chassis?

Nope, that would be like trying to find a needle in a haystack, remember what the wiring is like under there? its just a jumbled up mess of wires and I can't begin to sort out which wire goes where let alone where the green and white I-F transformer wires go. Although I think I noticed that maybe I wired it up wrong at the transformer itself, I think I might of swapped the green and blue wires by accident, which might explain why I'm not getting anything.

Also when I reconnected the coil after it came loose I'm not sure if I wired it up correctly or not maybe you could help me figure out if it was wired up correctly, or does it not matter which terminal the coil wires go to?
 
If you measure between pin 5 and pin 4 of the 7c6 What do you read? if over 3 meg, There is some continuity through the IF but it would have to be opened again to check it
 
I don't think, but not sure, it matters if the primary and secondary are swapped, but each coil is 20 ohms if you wired them up swapping blue and green there would be no continuity for either side.
 
I don't think, but not sure, it matters if the primary and secondary are swapped, but each coil is 20 ohms if you wired them up swapping blue and green there would be no continuity for either side.

Well I don't know then because I don't think I swapped the primary and secondary wires around, I wired the green wire to the terminal nearest the black wire and furthest from the white wire and the blue wire is wired to the terminal closest to the White wire and furthest from the black wire.
 
If you measure 170v to ground from the 7b7 pin 2 the primary blue wire is connected to the correct spot

OK, I'll see about testing that, although the 47k ohm resistor in the "new" IF Transformer I got was drifted higher than the one that was in the original IF Transformer as it was measuring at around 60k Ohms whereas the one that was on the original transformer was at 53k Ohms. Although I did notice that the red wire was measuring the 60k Ohms between it and the white wire and the green and blue wires measured together came out to about 23 Ohms (20 Ohms the higher value is due to drifting over time), and between the red wire and the unused tap where the other transformer core wire lead connects it measured 30 Ohms (20 Ohms, again there was some significant drifting in the transformer core winding over the years), and between the blue wire and the white wire, I get no reading, and between the green wire and the white wire I get no reading, which apparently means something still isn't right with how I wired up the transformer core to the variable capacitor top, either that or I wired up the wire leads going into the IF Transformer wrong.

I measured the voltage on pin 2 of the 7B7 and it was giving me a funky readout that wasn't a steady 170v, it was giving me a strange flickering readout that was showing 8.3 and then doing a really fast flicker between V and mV, so I'm take that as it meaning that I don't have the IF Transformer wired up correctly, and that I had somehow swapped ALL of the wires from where they were supposed to be.

EDIT: Well I was looking at the Primary IF Transformer that came with the scondary IF Transformer that I had ordered on fleabay and it seems that I maybe did get the IF Coil Wiring mixed up, because the Primary IF Transformer has the two outer wire leads wired together on one side and the two inner wire leads wired to the other side and I have the top inner and outer wire leads wired up to one side and the bottom inner and outer wire leads wired up to the other side, which I'm guessing that's probably why I'm not getting anything. except for hum out of the radio side and no reception. But now as for which side the outer wires went to and the inner wires went to is what's gonna be the tricky part to figure out.
I guess I should of just left that piece of cardboard on that transformer coil and been done with it, then I wouldn't of been in this mess...
 
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It does seem that the wires got mixed up,as long as the red and blue measure around 20 ohms or something like that, and green and white measure around 47 k or something like that you should be in business.
It's a learning experience, I'm sure you have learned plenty during this exercise
 
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