While I have been into Amateur Radio since 1957 and restored a number of vacuum tube ham gear, this is my first effort at a Philco. It will be used as a non working, static display at our small local museum.
My project is a Model 39-80 found in reasonably good condition. Needs a bit of attention to the veneer trim, grill cloth is pretty much gone and the glass or plastic is missing from the dial bezel.
The photo is the first cleanup of the cabinet with Gojo, not for sure where to go next ?
Always open to suggestions from anyone having experience with the 39-80, happy to hear from you.
Welcome to the Phorum, Charles! I'm presuming that since this will be a static display you are not doing electronic restoration? Why can't it be a working example, that is, if you have the chassis? The cabinet is in fairly good shape for its' age. Just wondering... Take care and BE HEALTHY! Gary
"Don't pity the dead, pity the living, above all, those living without love."
Professor Albus Dumbledore
Gary - Westland Michigan
This radio is complete, only one knob missing and most likely could be brought back to working condition, the chassis appears to be pretty clean, which I have given thought to.
Also considered making a 120VAC power supply for the Philco as the museum would probably have no interest in batteries.
I just finished cleaning up an unknown, possibly a kit no makers marks, 1920s era TRF receiver for the museum and have a Hallicrafters, SX101-MK3, on the bench that has kind of been my priority to get completed.
I've seen one of those sets. The grille cloth I don't think is in reproduction but you check w/ https://www.radiogrillecloth.com/ and see if he has any suggestions.
On the dial cover https://dialcover.com/ Mark is your guy. Send him the brass frame and he will install a new cover. It's plastic and has dinky rivets holding the cover in else you could just pop it in.
I have one and restorted it some yrs ago. Finish was badly flaking and some black water marks on the sides. Refinish it and was able to lightly sand the black marks to a exceptable level. Grille cloth was pretty good. Chassis bad switch, battery cord, bad ground on 1A5 filament, burn up #25 800 ohm resistor, and had replacement opt. Replaced all foil and electrolytic caps.
After servicing it's a pleasant sounding set w/a surprising amount audio considering the 1A5 is good for .1 of a watt. It sound not quite as loud as a set with 50L6 but only draws 4ma plate current.
GLOM de N3GTE
When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!
Terry
(This post was last modified: 09-18-2022, 07:53 PM by Radioroslyn.)
The 39-80 is a farm set that uses a 1.5V A Battery and a 90V B Battery. It is a rather common circuit, as it was also used for portable radios.
There is a place in my heart for these farm sets, as these people did not have utility electricity. In addition, this was likely toward the end of the "Dust Bowl" era for the "Great Plains" states. There were different ways of having "off the grid" radio back then. Some farm radios were 6V Sets with a vibrator supply similar to car radios. The battery was either swapped with the one in the tractor or the Ford, or charged with a "WinCharger ™. Other farms had a 30V Delco single cylinder generator that charged 15 2V Lead Acid batteries, so 30V radios were available where both the A and B supplies were 30V. This total try cell (1.5V A, 90V B) set was probably for the boonies and likely played for about 100 hours before the batteries had to be replaced, therefore it was used sparingly, for farm reports, maybe news of the brewing war and maybe to listen to a religious service on a Sunday.
Rather easy to build a 90V power supply. not as easy to build a 1.5V supply. For the 1.5V, the radio would play for a while on a D Cell if only demonstrated for a few minutes per day. Worst case is to run it on a D Cell and a bunch of 9V batteries.
These radios probably went into the attic in the 1950s. Do replace the caps. If no mouse damage, repair is rather easy, tubes are plentiful and relatively cheap all things considered.
Good luck with it!
"Do Justly, love Mercy and walk humbly with your God"- Micah 6:8
Best Regards,
Three questions about this Philco 39-80, Chassis 121, see photo.
1. Two wires extending out side of the chassis was there originally an external antenna in the cabinet ?
2. One wire appears to attach to the Antenna Coil at the Detector/Oscillator and the other to chassis ground ?
3. The audio output transformer appears overheated (have not measured it)?
1 Generally Philco set didn't have loop ant till 1940 so it needs an external job. Also Philco sets from '39-'42 have rubber coated wire.
2 Yes
3 Now let me think about this. A hand full 9v batteries with about 4ma current flow is going to get the output transformer hot enough to melt tar off of it... [Image: https://philcoradio.com/phorum/images/sm...on_eek.gif] No. It's probably from storage hot vs cold causing the tar to expand and contract.
I wouldn't be surprised if the primary was open. It's a pretty hiZ like 14K or so. That opt is the original one mine has a replacement from yrs ago.
Hams can fix anything! Ask any of us.
When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!
Terry
(This post was last modified: 09-20-2022, 07:54 PM by Radioroslyn.)
Was just curious where those two wires went originally, as I do not see any connection point for an antenna internal or external to the cabinet.
Good point, I did see on the schematics the 90 volt supply had a very low current, will ohm the transformer. The fellow I purchased the radio from said it had been in his "shed" for around 30 years.
Kind of been pondering building a Battery Eliminator after encouragement from the Phorum Members, have most of the parts.
Went to ohm the output transformer today, when I moved the wires, all of the insulation fell off of the primary and secondary leads !
All other wiring on the chassis appears to be in reasonably good condition, did note a resistor replacement had been made on the audio amplifier tube, with two 1 meg placed in series.
Also have to admit, had to look up on how to read the resistor codes on these oldies---LOL.
Also appears the audio output transformer may be driving a 5.5 ohm speaker ? So wondering if a replacement transformer with a high primary impedance and 8 ohm secondary would be close enough ?
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