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1934 16B 5 band
06-23-2019, 08:56 PM
Wow... Im averaging 265 from my 80 tube..
 If you plan on running it for awhile, let me know your peak temp on the power transformer. Curious on the op temp.. Good to hear ya got life from it... Steve 
06-27-2019, 11:59 PM
A little up date. I wanted sort the replacement IF transformer under the chassis.On the original the resistances seemed ok I thought I'd pull it out for a closer inspection. To do so the three aluminum cans come off as one unit after removing 3 chassis screws and 6 screws that hold the IF trimmers cap in place. All was going well till I got to the last of the 6 screws. It was very tight and though it may have rusted. Small indent in the can and the head of the screw was roughed up a bit. Some one else had been at it before. Didn't give it a lot of thought. Gave it some WD-40 and time to see if that would help loosen this offending little bugger.
I gave it a sharp twist and it started to turn BUT it kept turning and turning but didn't unscrew out. Nutz! Was time break out the Dremel and grind the head off of is blighter! Ground it off to find that the screw still stuck to mating threaded bushing but on twisting it it cracked the ceramic portion of the trimmer in several places. GRRR! Now I had two questionable ift (the 2nd and 3rd). I'm thinking that what happen was that the grid wire on the 2nd ift was very tattered and was in need of replacement. Someone started the remove the cans and got stuck at that last screw and decided to just add a replacement to he under side rather than trying to get the original apart. Ed H comes to the rescue as he has some spares and is graciously sending them along to me. So by next week I can get started back working on the IF strip. I should be pulling the shadow meter out and rewind it while I'm waiting... 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
06-28-2019, 12:54 PM
Will try and get all the bits in the post to you this weekend Terry.
I don't hold with furniture that talks.
06-28-2019, 06:31 PM
Got busy and rewound the sm coil. Here's a couple of pics. Ohms out @ 1051. 40ga wire = 1 ohm per ft so there's 1,051 ft of wire on that dinky bobbin!
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
06-29-2019, 06:38 PM
Uh oh! he's done already. Better get those IF cans wrapped up...
Nice Job on the shadow coil Terry! I don't hold with furniture that talks.
07-10-2019, 09:47 PM
While I was waiting for the IF transformers to get here I replaced the rubber bushings under the tuning cap. Have a few a spare regular grommets I fashioned replacements for the two front holes. The two lower bushing in the front were in pretty good shape so I used them for the rear mount as it's a bit more difficult to access and those popped right in place.
Shadow meter is mounted but need to route the wires back to the bakelite block where they connect. The 2nd IF transformer modification is removed and the original is back in place and wired. The 3rd IF transformer is wired in (thx Ed) so the IF strip is ready to go. Tomorrow going to test the tubes and attempt an alignment on the IF to make sure all is well. Found some rubber to retread the large hub on the dial drive will see how that works out More Later 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
07-12-2019, 01:12 AM
Tested the tubes and most were pretty good but the two 78's (IF amps) and the 77 (mixer) were not so hot. Found a few replacements and gave them a try. Fired the chassis up and all was well but the sensitivity was poor and volume low just picking up a few local flamethrowers. A cursory check didn't yield any obvious issue so it was time to break out the signal generator. Got it warmed up and set up for 460kc. I was surprised that the 460kc trap works really well and has a nice sharp dip in signal. The If transformers were way out of adjustment. After repeaking them a couple of times to be sure they were on frequency the sensitivity was restored to what it should be. Obtw the 2nd transformer was ok.
The dial calibration was off on the bc band abt 40kc. This may have been because of retuning the IF to match the replacement transformer. Anyway I was reading the alignment procedure and it seemed kinda confusing, I'm thinking it's because the generators used back then were not so accurate so they used a crystal to hetrodyne a harmonic to come up with a reasonable close frequency to align to set. With that in mind it's just a matter of sorting which trimmer adjusts what frequency. Got the bc band in good calibration. I'll tackle the short waves tomorrow. 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
07-13-2019, 05:13 PM
Hold the presses!
Yesterday morning I was all set the check the LO frequency w/ my little counter. Flipped the set on and was greeted w/a big cloud of smoke. This isn't good! It looked liked it was coming from the 7K bleeder resistor (it's the big one along the back edge of the chassis). What was worrying me was that right above it is the power transformer (that would suck if that was bad!!). Pulled the 80 out and checked the hv at the plates and it was good (yay!!). Measure the output @ the 80 tube and it was down from 300v to 296 so that's good. Left it on for few more seconds to find the resistor used to replaced the shadow meter (1500 ohms) was the smoker. The 200v rail (fed by that resistor) that feeds the IF amps and mixer was at abt 10v (not so good), Did some resistance checks to find that the 2nd IF transformer was shorted. After doing a few more tests the short disappeared. Turn it back on and play fine. Wiggled the hv terminals on the IF can and seem to be ok. Wiring is good between the hv, IF can. and the other connections to the tubes. So it's up for further investigation. Maybe a scrape piece of wire got in between the trimmer and can. It will give me something to think about in my spare time. Started to look at the LO frequency to find that is pretty good but it seems that the tuning runs out of capacitance near the high end of the dial. I'm thinking I need to move the dial a little off center to give a little more capacitance. I have a local station @ 1440kc if the set the osc so that is in it's proper place and tune up yo 1500kc I'm @ 1460kc. Both trimmers work fine just not enough capacitance in the tuning cap. More Later... 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
07-15-2019, 11:37 AM
Interesting Terry - I hope progress continues without smoke.
My 16X adjusted well on the broadcast band, however, I could not get the dial to calibrate so well on the higher two shortwave bands. Some investigation of the mica caps might shed light on the issue, if I ever get around to it... I don't hold with furniture that talks.
07-24-2019, 07:53 PM
I ended up moving the dial over abt 3/16 off of center and was able the get the bcb within 5kc or so (pretty impressive). The SW bands not so much. the two lower ones are within 100-150kc. Band 4 is pretty close but the same adjustment is used for band 5 and the procedure sez to split the difference make both band off abt 75kc. I guess in isn't horrible unfortunately the sw bands alignment is only at one end so you'll kinda stuck wherever the other end falls. May try add so small caps to get it to track better.
Haven't sorted the smoking resistor will flip the chassis over and give it the acid test and beat on it a little and see if it will do it again. At this point I'm a little nervous about connecting sm More later... 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
07-25-2019, 12:16 PM
That dial adjustment rings a few bells Terry. I had a similar juggle with bands 4 and 5. I wonder why Philco didn't include independent adjustments, especially as this was a top of the line set.
I don't hold with furniture that talks.
07-25-2019, 05:58 PM
It brings to mind those 2 DO NOT ADJUST screws on the tuner..
These were factory set, what are the odds theyve drifted since then? And how to get them back in tune if theyre not? And what effect would they play in a MODERN alignment? Steve
07-25-2019, 07:05 PM
Ed,
Me thinks that it's using the 2nd harmonic from band 4 osc to operate the mixer on band 5. This is why the two share the same adjustment and the frequency is double. Bare in mind that this set was produced at the height of the depression and perhaps the Philco engineers got creative to cut costs. Would require a trimmer and a place to put it along w/a contact on the bandswitch. The saga continues. Found that the lo isn't running at the low end of band 4 and 5 (abt the first 1/3) or my counter can't make sense of it. Checked the cap plates and all looks good sez Homer the ohm meter. With the dial drive stuck in low gear I almost need a drill to get from one end to the other. Checked the 76 again and was still ok. Swap it out again just to be sure. Need to do a little more investigating to see if my counter is making a red herring for me to chase. Did find the the 25K plate resistor was 46K. After replacing it plate voltage went from 39v to 70v. Revisited what I did last time played w/the dial and alignment and ended up keeping it abt the same as last time. Now the SW bands are within 100kc or better. BC band is within 5kc. Steve, I'm going to sort the band switch, coils, and tuning cap sections and see if I can figure out what's what. Philco decided not to list those trimmers on the tuning cap w/the same # on the schematic vs the alignment instructions. Anyway I'm going to give it a go. 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
07-26-2019, 01:39 PM
Terry - yes I think you are right about band 4/5 interaction. A quick shot at the maths, using the dial ranges (5.8 - 12 Mc/s and 11- 23 Mc/s) and 460 kHz I.F. pans out within a few kc/s, if we assume the LO is on the low side of the received frequencies for band 4, and 5
I don't hold with furniture that talks.
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