[philco fan]

o.k.,got a philco for you guys,hope you can help,picked this up at the c.h.r.s. swap meet yesterday in san francisco,1936 philco 610,first try nothing, found bad 78 and 75 tubes,checked caps,someone replaced the two 8mfd's with 22mfd's,and the 16 with a 22, let the 22 that replaced the 16 alone but replaced the two others with the correct 8mfd's,fired it up again, tubes now lit,plays somewhat distorted and only near 1140 on a.m. band,picks this station up across a wide section of the a.m. band.the first s.w. band sort of works but seems to be picking up a.m. broadcast and the second s.w. band has dead silence.the cabinet has been restored and looks very nice so i'd like to get this one playing well also,any help is appreciated,please remember i'm a novice so if you can dumb down the tech stuff it would really help,i have a sig generator[knight kg650] so i just need to know settings on it so i can trace the signal also what is used for checking the output?,thanks,phil

[n9vu]

o.k.,got a philco for you guys,hope you can help,picked this up at the c.h.r.s. swap meet yesterday in san francisco,1936 philco 610,first try nothing, found bad 78 and 75 tubes,checked caps,someone replaced the two 8mfd's with 22mfd's,and the 16 with a 22, let the 22 that replaced the 16 alone but replaced the two others with the correct 8mfd's,fired it up again, tubes now lit,plays somewhat distorted and only near 1140 on a.m. band,picks this station up across a wide section of the a.m. band.the first s.w. band sort of works but seems to be picking up a.m. broadcast and the second s.w. band has dead silence.the cabinet has been restored and looks very nice so i'd like to get this one playing well also,any help is appreciated,please remember i'm a novice so if you can dumb down the tech stuff it would really help,i have a sig generator[knight kg650] so i just need to know settings on it so i can trace the signal also what is used for checking the output?,thanks,phil

I've had the same thing happen with a few sets. I'd swear it was the speaker or bad output tube, but not the case both times and more. Keep recapping. My advice is to get familiar with recapping and/or rebuilding the bakelite block units and any others outside of the bakelite blocks if any. You've got the right approach by replacing those bigger caps to a closer value. Maybe it worked but I think it's more likely you replaced a couple of bad capacitors, even though they look to be replaced by the prior owner. Who knows how old they were to begin with. Nice work. Keep on going.

[Terry Burns]

Hi Phil,

The best thing is to recap the whole radio as mentioned above by n9vu. Most of them are out of tolerance or shorted. I've heard the statement made you wouldn't drive a car on 70 year old tires so why operate a radio on 70 year old caps? Here is a link to Chuck Schwark's website about rebuilding bakelite blocks.
http://www.philcorepairbench.com/capbuild.htm
A schematic for your radio can be found here.
http://www.nostalgiaair.org/PagesByModel...013797.pdf


Hope this helps
Terry

[AI2V]

Gary is right-on; those 6 or 7 tar blocks need to be emptied and recapped. When you get good it will only take less than 2 minutes to remove and gut one.

First scribble a drawing of your first block and what goes to each of the three terminal strips; unsolder the wires and resistors (an excellent time to measure the resistors when one lead is not connected); remove the block and heat with a heat gun until the tar just starts to soften/liquify around the edges; using a small screwdriver, dig off the first 1/8 inch of tar (should expose the caps); now carefully pry out the caps. When the caps are out and the block scraped out, push a drill bit through each of terminal holes to clear out the old leads. At this point you are ready to clean off the block (acetone), remove the excess solder and broken leads from the terminals, and install the new caps. The values in these blocks are very UN-critical with the exception of the 110uuf (I use 120uuf) in the detector stage. When doing Philco's, you've got to learn the process and this is one step that cannot be skipped.

[Jimony]

And I found that many resistors increase up to 10 times in value. Change them also.

[philco fan]

thanks guys for the advise, i do the cap blocks as soon as i can stock up on replacements,i'll post results asap,thanks again,phil

[n9vu]

Gary is right-on; those 6 or 7 tar blocks need to be emptied and recapped. When you get good it will only take less than 2 minutes to remove and gut one.

First scribble a drawing of your first block and what goes to each of the three terminal strips; unsolder the wires and resistors (an excellent time to measure the resistors when one lead is not connected); remove the block and heat with a heat gun until the tar just starts to soften/liquify around the edges; using a small screwdriver, dig off the first 1/8 inch of tar (should expose the caps); now carefully pry out the caps. When the caps are out and the block scraped out, push a drill bit through each of terminal holes to clear out the old leads. At this point you are ready to clean off the block (acetone), remove the excess solder and broken leads from the terminals, and install the new caps. The values in these blocks are very UN-critical with the exception of the 110uuf (I use 120uuf) in the detector stage. When doing Philco's, you've got to learn the process and this is one step that cannot be skipped.

I just did my first rebuilding of a bakelite block capacitor. This is almost easier than it sounds. The inner portion only contained one .01 mfd cap and was relatively easy to stuff inside the housing. After doing a few of these, the radio's audio shows signs of improvement. There's alot more to go.

One question on this subject though. Is it necessary to restuff the bakelite blocks with a material simular to the tar that was inside it prior to removal? I've heard that it's almost not worth the effort. With no insulation the newly installed cap itself will far outlast what used to be in there. Comments? Suggestions?

[Terry Judkins]

I just stick the cap in turn the block over and solder the leads. Nobody can see under the blocks and potting is not needed.

[philco fan]

hi terry,gary and pete,got back to the 610,before i go on i should have mentioned before that when initially trying radio after tube and filter replacement when i connected antennae to the clip on chassis i got nothing but static,but i connected it to the top of the 6a7 thats when it started to play but only around 1140 a.m. and the same frequency across alot of the band.now that i have explained that maybe the diagnosis will be different .here's what i've done so far in this order,checking results with each step to make sure i didn"t make it worse.replaced part #30-4020 with .05,no change,4989-dg with .1,no change,3903-su with .01disc,no change,33-1096 1meg,measured at 1.4meg,replaced with 1meg.,no change,4989-dg with .1,no change,3793-su.047,spec is .015,no change,30-4170,.1mfd,no change,and 3793-dg.12 ,spec is .015.this last change resulted in a audio hum which i didn't have before. does it matter what kind of caps i use for replacements? do they have to be mica or mylar or whatever else is out there?i'm begining to think i have a antennae problem inside the chassis or some tuner problem. i haven't changed part #4989-fu because i don"t have the right parts. are the parts i put in that don't match spec critical values? any new suggestions are of course appreciated,thanks,phil by the way,gutting the bakelite blocks was easy,took about 10mins. each,thanks for the encouragement.

[Terry Burns]

Hi Phil,

Sounds to me like your oscillator is not working. This generally happens when you get the same station across the dial. To see if it is working take another radio, a transistor one just because it's easy to handle and set your Philco on 1000khz. Tune your other radio to 1460. That's 1000khz + your I.F. frequency of 460khz. You should hear a squealing in your radio. If not then your oscillator is not operating. Change the tube and for sure check the osc. coil which is Part # 8? Seem Philco's have a problem where the wire ties into the coil lug. Check continuity and look for some green corrision at the terminal. It also would not hurt to clean the band switch. I'm sure some of the guy's can help you more but it's a start.

Terry