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Philco model #20
#16

Hello MrFixr55 thanks so much for the input , what I am going to do is change every capacitor in this set and also every resistor , for the resistors I have ordered 2 watt for all of them except for the long wire wound resistor #6 and #7 that had the jumper across it I have ordered a 1K 10 watt like you told me , I did take off the jumper and tested the #6 and #7 tabs and I got 975 ohms , I have no idea why the jumper was put in , I was thinking that. Maybe when the set warms up that section opens with the heat expansion? , so I thought I would disconnect that section and install the new 1K 10 watt resistor , I have not and won’t power up the set until I change all the parts don’t want any undo problems , this is the first set I have seen or or worked on that has two output transformers , oh well hope both are ok again fellows thanks for the input and help all the very best Rick
#17

Rick, 

There should be only one output transformer, it should be mounted on the speaker. If there are two, someone has made some sort of crazy modification.

Steve

M R Radios   C M Tubes
#18

I am pretty sure Rick means the interstage and the output xfmrs.

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.
#19

Sorry fellows for the mix up , when I look at the parts list and schematic I see part #21 is a push pull Input transformer and #28 is a Push pull Output transformer also there is part #27 with only two wires on it this is a filter Choke , when I looked at the two push pull transformers they had three wires on one side and two on the other side on both , I just thought that most push pull output transformers I have worked on look this way , I am wrong never seen a radio that had two transformers that both looked like output transformers , oh well learn as I go and thanks for the lesson , you are right this set has the output transformer mounted on the speaker ,this set is a floor model not a cathedral, low boy style, thanks again all the very best Rick
#20

The interstage transformer has to take some serious current, 3-5mA, which is not a small thing considering the signal amplitude. So they are size of output transformer, in 20, in the 86 - 112 radios, same thing.

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.
#21

Hello again fellows , got all my condensers and resistors today , one problem I had asked for a .15uf @ 600 volts orange dip , they sent me a .25uf @ 600 volts , this condenser is for the metal can filter condenser,it calls for a .13 Uf goes onto #2 contact to #6 contact or tab , will the .25uf 600 volt orange dip be ok to use where the .13uf condenser goes , I will hold off putting it in until I hear from you fellows , again thanks for all the help , take care all the very best Rick
#22

Well....I doubt you will see the difference.
This said, it is not really part of the filter.
Were it part of a filter, I'd say, no difference; this one, however, is to compensate the residual ripple after the inductance. As you know, capacitor shifts the current -90 degrees vs voltage, whereas inductance does the opposite, so the two of them create two ripples 180 degrees apart, and if sized right, the cap could cancel out the residual ripple.
Philco calculated that value to be 0.13uF.

Now, many of us simply do not even populate this cap, as we found out it is not effective at all, and simply beefing up tthe second filter cap (lugs ## 1&4) could have much better effect on the ripple and thus on the hum.
I think at the time they simply did not have good caps, so the second cap (not the 1st one) could be increased quite a bit. A 20uF cap is not out of the question.

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.
#23

Thanks for the help , I will solder the condensers in the cap of the can tonight , what I did was take the rectangle can out of the radio and separated the bottom of the can cut the wires and dug out as much of the tar that I could ,now I will solder in the capacitors on the under side of the can lid , I now have room with the tar removed to put the can back together with the capacitors soldered to the underside of the can lid , so it looks oringinal ,thanks again for all the help and taking time to answer my questions I really appreciate it, take care and thanks again , I will let you fellows know how I make out trying to bring this old set back to life , all the very best Rick
#24

hello Rick,
Sounds good I am looking forward to seeing and hearing about your progress .
I have a Philco 38-10 that I will be working on this following week since I have it off for vacation !


Sincerely Richard
#25

Next time (unless you meat the same) try to do this:

Treat it same as a backelite can:

- Cut the wires coming out from the inside the can to the solder lugs.
- Then remove the can after unbolting it.
- The phenolic panel therefore is left in the radio with all wires coming to it still soldered to it.
- Clean the lugs (only if you want it).
- Then gut the can.

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.
#26

too late I unsoldered the wires going to the can then removed the can form the radio separated it from the phenolic panel cleaned out enough tar and old foil condensers with chisel giving me more than enough room for the new condensers to go in the under side of the can not on the outside surface , now I have to resolder the wires going to the can back on , I drew a pitcher of all the wires and what tab they went to also I taped masking tape on each wire I took off and marked what tab it goes to just to make sure they went back to the tab on the can where they belong , wish I had done it your way morzh would have been easier and a lot less soldering , now looking at my drawing I don't know why there is a jumper wire going from tab #4 to tab #6 ? on the condenser can . is this right I also wondered why there was a jumper on the long wire wound resistor from tab #6 to tab #7 , I took off the jumper on the wire wound resistor and got a new 1K 10 watt resistor and will unhook the number 7 tab on it and install the new 1K 10 watt resistor , if you look at page one there are photos and you can just see that jumper on tab #4 going to tab #6 , to me it looks like it was factory installed but seeing what was done to the wire wound resistor makes me ask myself is this right , just can't see it on the schematics , thanks again fellows for all the help all the very best Rick
#27

>> jumper wire going from tab #4 to tab #6 ?

If you look at the sch, you will see your answer. Try to get to read it. I will give you the answer if you get lost, but I want you to get proud of yourself tonight when you figure it by yourself.
https://philcoradio.com/library/index.ph...chematics/

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.
#28

Hello morzh thanks for the test , I think I might have it ,when I look at the data sheet that has the drawing at the bottom I don’t see #4 and #6 tabs joined together but after looking at the schematic even drawing it out on a blank paper sheet and it took me some checking I found on the schematic it has a number 4 and number 6 printed there and shows them joined but not on the drawing with all the tab numbers on it so I now think yes these two tabs are joined with a jumper on the outside tabs of the can , now saying that I would be very thankful if would let me know if I am right , thanks again all the very best Rick
#29

The diagram of the can shows THE CAN, that is the part itself. Kinda like a backelite block in Ray Bintliff's book. It has no wires outside.
You wouldn't draw a resistor or a vac tube panel with wires in a datasheet, would you?

Then the sch shows the pins connected. This is where the pins get wires drawn.
In that sch the pins 4 and 6 are wired together.

   

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.
#30

Hello again fellows , well I powered up the set this evening after I had changed every cap and resistor in this set and two tubes , the 80 and 27 tube , I did not try and power up the set befor I changed all these , some of the caps were dead and the resistors were way off spec , two of the 500K were 950K , the set looked untouched almost like new , crossed my fingers and used my variac and brought it up slowly, it came back to life , it has great reception picking many stations , the only problem is the volume of this set on local stations , it’s way too loud even when turned down to the lowest , I have to offset the tuner even with no antenna on it at all , and when I just touch the volume control the volume goes back up , I sprayed it with dioxit , that made it smoother with no cracking noise while turning but the volume works just the same too loud on local stations so I have to off set the tuner , I know the antenna is hooked to the volume control , is this normal on this type of set and is there anything I can do to change this a bit , thanks for any help with this and all the help you fellows have given , all the very best Rick




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