Philco 60B block condensers doubts -
CarlosRadio - 03-01-2024
Hello,
I am repairing a Philco 60B and I have doubts about the block condensers
[Image:
https://dl.dropboxusercontent.com/scl/fi/q117cg2w3a7ssu5ntk42w/philco60B-3sca.jpg?rlkey=bn8hf532hslnari48jfqffpl8&dl=0]
In the schematic, number 8 has a single 0.180uF capacitor. To which terminals should this capacitor be connected?
[Image:
https://dl.dropboxusercontent.com/scl/fi/0n3y7wpch3x6xk771662y/philco-60b-block-8.jpg?rlkey=ncfcwsegomhtrgy9d5y1mo74x&dl=0]
Thank you, Greetings from Spain.
RE: Philco 60B block condensers doubts -
Radioroslyn - 03-01-2024
The diagram shows it at the cathode of the IF amp to ground. Inside the block it may have two caps that are connected in parallel externally do to their large value. The other possibility is that one of the lugs is a tie point. Look down the eyelet hole to see a small wire from the internal cap. If not it's a tie point.
https://philcoradio.com/library/download/service%20info/service%20bulletins/Philco%20Service%20Bulletin%20164.pdf
RE: Philco 60B block condensers doubts -
CarlosRadio - 03-02-2024
Thank you, Radioroslyn
RE: Philco 60B block condensers doubts -
CarlosRadio - 03-02-2024
This coil has an open secondary.
[Image:
https://dl.dropboxusercontent.com//scl/fi/w60cor387yrnai0dznyxt/Philco-coil-2foro.jpg?rlkey=88mr7q5vng7eoxfyfv8jnz7pw&dl=0]
Also, one of the secondary wires has a loose connection.
[Image:
https://dl.dropboxusercontent.com//scl/fi/lxgtlya3183yox71jkqbu/philco-60B-coil-4foro.jpg?rlkey=r5umo3j72segp6nseonz5ivh7&dl=0]
The problem is that I don't identify this coil in the schematic.
RE: Philco 60B block condensers doubts -
Chas - 03-02-2024
In my opinion, there is also what seems to be a second RF coil and an associated mica capacitor. These do not appear on the schematic and do not appear in the diagrammatic.
I suspect these may be antenna traps to reduce either nearby interference or navigation systems.
They will likely be attached to the antenna network either in series or parallel.
I suggest you sketch them into that portion they appear to connect.
Some 90 years since this radio was new and exciting, I hardly expect that the same stations or interference still exists. Get a second opinion by posting the schematic with the additions. I, would do so then remove the devices.
I do note that the coils are orthogonal placed so they do not interact.
GL
Chas
RE: Philco 60B block condensers doubts -
Radioroslyn - 03-02-2024
Those two coils are not original to the set. They may have been added to "repair" the original coil which may be open
https://philcoradio.com/library/index.php/shop-talk/techniques/rewinding-philco-coils/#Philco_60 Or may be some sort of a trap for lessening a strong local signal.
Good Luck
RE: Philco 60B block condensers doubts -
CarlosRadio - 03-15-2024
Hello friends
I have another problem: the primary of the speaker transformer is open. I don't have any tools to rewind this. My only solution is to get a replacement part.
Does anyone know where I can get a transformer like this one?
[Image:
https://dl.dropboxusercontent.com/scl/fi/d85rufelgv19rip0i6kf9/Philco-60B-altavozpost.jpg?rlkey=dmkkhowf6vcv6y1dkvzhc7q5v&dl=0]
RE: Philco 60B block condensers doubts -
Radioroslyn - 03-16-2024
"Like" is an interesting word. You could get another Philco speaker with a good transformer. I'm sure that it used on several different ones. Or you could find a spare (random) from another set with the same or close specs. Thirdly I took a look thru some of the venders and found this
https://www.tubesandmore.com/products/transformer-output-5w-5k-8k-primary-options-upgrade-fender-champ I don't know about the size so there might be a little bit of fabricating to space it back from the field coil
GL
RE: Philco 60B block condensers doubts -
Brad Winder - 03-16-2024
I've used one of the several Hammond universal transformers that they offer, and they do fit inside the Philco transformer frame. I believe that I had to add some cardboard shims so it was tight...it's been a few years, so I don't remember all the details.
RE: Philco 60B block condensers doubts -
Radioroslyn - 03-16-2024
I like the Champ as the pri inductance in higher equaling better frequency response and the cost is about 1/3 less. I pulled out my micrometer and sized it up vs a K speaker I had laying around. Seems like it would drop in. Screw holes are on the button and should clear the fc. If the choices where closer in specs or price I may have linked a different one. Yes the 2ndy impedance is about double what is need for the voice coil but it's difficult to find a 1 1/2 ohm 2ndy without using a mulitmatch transformer. That's when price goes up...
I don't say this to be argumentative but only to say that this will performer fine with some mismatch. For all of us retired guys that are looking for reasonable opt w/o spending $60+ I'd buy 1 if I had a set w/a 47,2A5,41,42, or 6F6 that had a bad opt.
RE: Philco 60B block condensers doubts -
RodB - 03-16-2024
I agree Terry. A tone control adjustment and a slight increase in the volume control will compensate for a slight opt mismatch.