Just picked up a 1936 Philco 116B Tombstone Radio Today and need some info on it
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I've got some capacitors on the way from one of the members here that said he would send me the capacitors I needed to help get this radio up and running.
When he was looking up the capacitors the radio needed he found a capacitor or two that wasn't listed in the parts diagram in the Rider's Manual for the radio but but they were listed in the parts list, so he and I both have no idea where those capacitors go on the radio.
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OK, so I got my capacitors in on Monday, and I am starting work on this radio, and I was monkeying around with the switch to try and get it going again and it seems that the power switch itself is actually working as it should (at least according to my DMM's continuity test it is).
I was able to get the switch apart and flush it out with some contact cleaner and I put it back together and confirmed with my DMM that the power switch was indeed working as it should but when I plugged in the radio to test if the switch was actually working the power switch was off, and the radio was powered on still.
So something is still not right with the power switch circuitry I'm still wondering if something is bypassed or if something isn't wired right.
Any thoughts?
Also my radio came with the optional headphone jack on the back for private listening and there is a paper cap going across it and its not on the service data.
Anyone have any idea what should go there?
OK, so a little update on the power switch: Its definitely going to need a new switch, because I unhooked the hot lead going into the switch and plugged it in and the radio was dead as it should be, which means I have a bad power swich, and even when I went to test the fuctionality of the power switch with my continuity tester on my DMM with the hot lead disconnected on the power switch, sure enough I had continuity with the switch both in the on and off positions, the previous tests were false positives unfortunately.
So does anyone on here have a spare volume control/power switch assembly they could part with to help me get this radio going again?
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I guess we assume a defective switch is an open switch. But didn't the radio come on before your disassembly?
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Yes, that's the point, the radio came on with the switch in the "off" position, meaning that the switch wasn't actually turning off the radio when it was in the off position, meaning its a defective switch, that is stuck in the "on" position, which its not supposed to be, hence the need for a new switch.
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Probably a resistor across the cap and covered. Hard to put in perspective with close up pics.
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I did get the power switch issue fixed, I ended up having to use Liquid Wrench on the power switch to get it freed up, followed up with a good cleaning with contact cleaner and now the switch works as it should.
I think I figured out my low volume issue, someone at some point time, replaced the 37 tube in this radio with a 84/6Z4 Rectifier tube...
So now i need to source another 37 Tube for my radio.
So what would of made someone think that a rectifier tube would of worked in place of a triode tube in a detector circuit?!
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I figured out what the black thing is on top of the one capacitor, its a 300 Ohm wirewound resistor of the flexible variety, which I was told to just leave that capacitor alone because that resistor that's attached to that capacitor shouldn't be moved around too much as it could break.
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OK so I've made some progress, I've restuffed a couple of the bakelite blocks (it was actually quite easy once I was able to get the wire leads from the old capacitors taken care of), and I powered on the radio and the radio's sound quality perked up by about 250% from what it was by just restuffing 2 of the bakelite blocks and replacing the oddball .00125 MFD capacitor (which I was able to replace with a .001 MFD Capacitor I had laying around that I had forgotten I had).
Only thing I've noticed is that the tone control switch tends to hum a little bit when you switch in between the different tone modes, which it sounds like a loose ground kind of hum, the hum goes away as soon as you take your hand off the tone control.
Any ideas as to what that hum might be?
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Whats the easiest way to go about taking care of the bakelite blocks that are harder to reach and that have coils attached to them?
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I restuff all the bakelite block caps even when they are under other components. The only way I know is to take the items out that are in the way and then replace them.
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Sometimes the wires that are connecting it on one side can be unsolder to flip the block over thus gaining access to the bottom.
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
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This is where a decent digital camera comes in handy. I take pictures of the underside of the chassis as close as I can and still get a sharp focus. This is a great help to remember what is connected where. I de-solder everything connected to any condenser blocks and make a careful drawing showing what goes where. I then remove the condenser block entirely. I place it with the filling side down on a little tray made from aluminum foil, and put it in a low oven, about 250F. I let it sit there for about a half hour. This melts out all the black goo. I remove it, and then pull out the old guts with a pair of needle nose pliers. Once they are out, it is just a matter of replacing them with new ones. The new yellow poly caps are a lot smaller than the old paper ones, so this is no problem. I fill the extra space with crumpled plastic wrap, and top it off with a piece of paper and then black RTV. If the radio has condenser blocks I just rebuild them all this way. No point in doing one, and then hoping the others don't soon fail.
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Quote:This is where a decent digital camera comes in handy. I take pictures of the underside of the chassis as close as I can and still get a sharp focus. This is a great help to remember what is connected where. I de-solder everything connected to any condenser blocks and make a careful drawing showing what goes where. I then remove the condenser block entirely. I place it with the filling side down on a little tray made from aluminum foil, and put it in a low oven, about 250F. I let it sit there for about a half hour. This melts out all the black goo. I remove it, and then pull out the old guts with a pair of needle nose pliers. Once they are out, it is just a matter of replacing them with new ones. The new yellow poly caps are a lot smaller than the old paper ones, so this is no problem. I fill the extra space with crumpled plastic wrap, and top it off with a piece of paper and then black RTV. If the radio has condenser blocks I just rebuild them all this way. No point in doing one, and then hoping the others don't soon fail.
Mike, I was able to get the majority of the bakelite blocks rebuilt with them still wired into the radio, there was only 2 of them that I had to remove a couple of wire leads from to get the bakelite blocks out of the chassis enough to remove the guts but thankfully they were easy enough to remember where the wires went to because the were all on one side of the blocks.
And the radio is definitely performing much better now than it did when I first got it (I even did an IF and RF alignment by ear and the radio perked up even more, surprisingly enough the IF and RF alignment wasn't very far off.)
Anyways the radio is almost ready to go back together (minus refrinishing the cabinet).
I also figured out that almost all of this radio's broadcast spectrum is still in use to this day the lower quarter of the old Police Band on this radio is actually the rest of the AM band (the AM band on this radio only goes from 540 KC-1500 KC) and the modern AM Band goes clear up to 1720 KHz (which on this radio is the lower quarter of the Police Band on this radio which is 1.5 MC-1.72 MC or 1500 KC to 1720 KC) after that the rest of the old Police Band on this radio falls under the current SW I Band and then the current SW II band is the Night Time SW Band on here, and then the current SW III band is the Day Time SW Band on here, and then the Long Wave Band on here as far as I know does have some use in Modern times, but I wasn't able to pick anything up on it around where I live anyways.
Just some interesting stuff I found out about this radio while monkeying with it today.
Also as for the shadow meter on my radio, it does work but just barely, and I took some measurements of the resistor that is inline with the shadow meter and that resistor is a 1,000 Ohm resistor and it isn't very far off, as it measures around 860 Ohms (it drifted, but down, rather than up) which is still within tolerance, and the shadow meter coil measures around 940 Ohms which is around what its supposed to measure, its not open in other words. So, I'm not sure what's going on with the shadow meter and why it barely moves when tuning in a station.
And then there's a paper cap that is tied into one of the wafers on the band switch on one side and then the other side is grounded to the grounding braid that is attached to one of the screws that holds the tuning capacitor to the chassis, and I can't figure out how to get that capacitor out and swapped out for a new one because its in such an awkward spot to get into that I can't even get to it with my pliers to remove it, any ideas of how to go about removing that capacitor? In case you're wondering its #23 on the parts diagram in the Rider's which is a .05 MFD Tubular Capacitor.
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To get the braid unsolder from the bolts this works well: https://www.ebay.com/itm/WELLER-Solderin...SwDoNeBPYp It's mis listed here as it's one of the older 325w units and is better than the newer 260 watt. Might need a tip. [Image: https://philcoradio.com/phorum/images/sm...n_cool.gif]
Most of the time the rubber grommets under the tuning cap are shot making the cap wobble and cause the tuning shaft to rub on the cabinet. The fix is to unsolder the braid, remove the 1/4"hex screws and replace the grommets.
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
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