[jerryhawthorne]

Hey, Groundhog, we have something in common.
Just got my nice schematic package from Chuck and it started some questions.
1. Both of the electrolytic cans have been replaced. One is a dual 10mfd, the other is, well, unknown. No markings. The dual 10 has both positive leads hooked together, presumably now a 20.
2. According to the documentation I have, the parts list lists the two caps as items #56 and # 57, both 10mfd +6mfd dual caps.
3. Chucks schematic lists those 2 caps as 6mfd each. I can find no other locations for the "other" half of the caps. I'm thinking that perhaps they used the double caps tied together to get essentially 16mfds for each.

Thoughts on the above? I have some 15mfd caps at 450 volts and thinking about using them an restuffing the original caps I hope to get tomorrow.

Thanks for any input.

Jerry

[TA Forbes]

The single 47 model 90 only has two electrolytic caps, both are 6mFd. Never assume the "technician" that repaired your set did it the way it should have been done.

When you replace the two electrolytics, install your replacements so that they are as shown on the schematic.

I used 6.8mFd caps on my 90.

[jerryhawthorne]

Thanks TA, it was the parts list that listed each as being a 10 and a 6mfd dual caps. Not having any of the originals installed just made it confusing.
Jerry

[TA Forbes]

Hello, Jerry: the confusing listing is this: for 60Hz power use 6mFd, for 25Hz power use 10mFd.

[jerryhawthorne]

Now that makes sense thanks TA. I just got home carrying with me a 90 parts radio so I should be in good shape with some original looking e-caps for restuffing.
Jerry

[jerryhawthorne]

Well, I picked up my parts chassis and have some time to look at it when I got it home. Certainly is a 90 and has the original electrolytic cans but the underside seems to have a lot more "hanging" caps in there. The chassis had a 47 tube in it. The area next was missing the tube. In my single ended chassis, it would be a 27, in the PP it would have been another 47. I am suspecting this is a PP chassis. The parts chassis also has stamped on both sides in a black stamp "SPECIAL". Not certain what that means. The small label on the back of the tube shield has a color more like tinfoil. Mine, the standard yellow like. The serial number is also on the paper the label is setting on. See the picture attached of the two chassis side by side.
If it is a dual 47 I will have a problem if I decide to use this chassis in that it has no speaker/output transformer. I suspect the speaker itself is interchangeable but the OPT would be very different.
Is this parts chassis somewhat valuable? All I need out of it is the old electrolytic cans and a couple cap blocks to replace in my single ended original chassis that some early restorer decided when an internal cap went south to break off the lugs to hang the replacement in the air.

Your thoughts please are appreciated.
Jerry

[Image: http://i303.photobucket.com/albums/nn129...hassis.jpg]


[Image: http://i303.photobucket.com/albums/nn129...0label.jpg]

[Steve Davis]

Jerry, it looks to me like your parts chassis is also a single 47 output. The surefire way to tell the PP 47 chassis is look at the tuning condenser, if it only has three gangs, it would be the PP 47 version.
I think the "special" refers to fact that this chassis was designed for 25 cycle power. That is a good thing, because it has a larger power transformer. It will work fine on 60 cycle power.

Steve

[jerryhawthorne]

Thank you Steve, you have cleared up a few things. After looking closely, yes, the power transformer is more substantial. Suspect that solved the SPECIAL label which was lightly taped on the shield. After cleaning the tube layout on the shield of the parts radio, it clearly shows PP45s. The label looks untouched from being placed on. My guess is someone some time ago changed the shield for some reason as this radio could not have used PP45s as there is only 1 tube socket with 4 pins, the one for the 80. Both chassis have 4 gang tuners, which according to your information would limit them to a single 47 if I read you correctly.
Looking at the bottom of the chassis, sure is a lot of difference in "added" caps. On my main chassis, it is easy to account due to a couple of bad caps in two of the bakelite blocks. On the parts chassis, just looks like a lot more and most look to be original.
I will sort things out and use the others for the few parts I need. Perhaps someone else can use some parts from it as well. A quick check on the A/C in to see if the primary of the transformer was OK, well looks open. Then again, could be the on/off switch. Little more looking there. A lot more iron on that 25hz transformer!
Jerry

[jerryhawthorne]

Anyone out there that has been following, well, got the nice detector transformer rewound back from Ron. He sure does a nice job. Installed and got a few radio station, not well but enough to think things are about right. Today, I thought I would try alignment. I'm not the best at this but set up my frequency generator to 175 and hooked to the top of the first detector tube with the clip off. Nada. No tone. OK, I'm clever moved the generator around frequency wise and there was the tone! 200 KC. Must have been a magic screw driver in there. It was so far off that all I could do was lower the generator a little at a time and peak until such time I got it down to 175. If I have the energy, I may try to try the radio again, before the IF alignment I had the two locals stations but a lot of howling and screaming in between.
More later and probably some questions.
Jerry

[jerryhawthorne]

Ok, well IF aligned and a little better. Off to the rest of the trimmers per the Philco instructions. Seems their techs only carried signal generators for two different IF frequencies. They used harmonics to get to RF frequencies. Well, I'm not looking for the fourth harmonic to aligned to a given RF frequency. Just adjusted mine to the RF frequency they were looking for. Well, it came in well. Only one trimmer which I noticed was open so far, I could squeeze it closed with my fingers need a lot of turning. Over all, I'm happy with it. Well short of the grill cloth which isn't so bad to toss it (heaven forbid) but would like it to look a little less holy. Sorry Ron, not be confused with a religious discussion.
It is now pretty much ready to replace my 111 which the nice lady I bought it from wants back. You may have seen some previous posts on that situation. Not as nice as the 111 but fills the bill.
Have a nice Thanksgiving all of you out there in Philco land.
Jerry

[jerryhawthorne]

Just adding another question now that the Philco 90 is running pretty well. A few things to sort but getting there. My question is what would you suggest for the grommets (3) that attach the tuning caps to the chassis? I get a little confused searching through various web sites. The tuner just rocks back and forth and the grommets are crispy critters. Thanks for any advise.
Jerry

[Groundhog74]

Jerryhwthorne I ordered the Philco 90 tuner grommets from Radiodaze. But I think I installed them upside down because when I installed the chassis in the cabinet the tuning dial sits a little too low. I installed them from the bottom with the thicker side down inside the chassis. I had a 50/50 shot and naturally got it wrong. When I start work on it again I'll reverse them and it should be ok. Mine were petrified and I don't think even CSI could have determined what they originally looked like.

[jerryhawthorne]

Thanks for the information. In looking at mine I would say your correct that the thicker side of the grommet is on the bottom side of the chassis. They don't look like a lot of fun to replace! Which ever way sets the tuner height proper should work.

Jerry

[Ron Ramirez]

No, the thicker side should be on the top of the chassis, underneath the tuning condenser, in order to set the tuning condenser at the proper height.

[jerryhawthorne]

Well, I would certain go with Ron. I looked at my chassis and it appeared the wider part was underneath. Then again, could not really see the top side. I went wimpy on mine and just added another washer under the original from underneath and tighten the three up. You can't really see the added washer but it was enough thickness to allow the old grommets to tighten down nicely. They were not falling apart, just shrank enough to allow the rocking of the whole tuning assembly. I guess when I get it back in the cabinet I will see how the tuner shaft fits.
Jerry