Philharmonic Amp/Powersupply

[Scott Seickel]

Hi all,
Due to the generosity of our leader here, I was able to obtain a rough- yet serviceable amp/power supply for my Philharmonic AM-FM.  It is a pre-FM supply that uses 5Z3 rectifiers.  As you can see from the pics, someone drilled holes and installed a transformer where the filter caps were.  It needs rechroming anyway, so I can easily weld up the holes and grind smooth for chroming.  There are other smaller holes in the sides that someone used to mount components for "whatever" they were building.  No big deal.  Easily fixed.  My gut tells me to restore this amp as an original early Philly amp/power supply.  I just feel like I would do further damage by all the work that needs to be done to convert it to a later FM supply - like changing the rectifiers to 5U4's.  I assume that the change to 5U4's was because of the added FM circuitry.  The FM band is worthless anyway, so maybe I can just run my radio with this amp/supply if the FM circuitry is not powered up.  Thoughts?

Questions:
-  Regarding the line with the 4 pin plug coming off of the radio (On-Off switch).  Why does this amp chassis have no place for that to plug in?  According to the schematics, even the early Phillys have a receptacle for this plug.  The FM-AM Philly power supply on Pg 101 of Mr. Hobbs book has no receptacle for this 4 pin plug.  Yet the FM-AM amp on pg 100 (for the Phantom) had this 4 pin receptacle.  The original FM-AM Philharmonic manual does NOT show this receptacle on the amp/power supply chassis.  It does mention- in the text-  this ON-OFF cable connecting to "the plug on the chassis cable" whatever that means.  The 4 pin receptacle that shows in the pics (of my chassis) is one that was put in to replace the original 7 pin that was there. Probably put in by whoever hacked this chassis. 

-  Does anyone have some quality pics of this chassis that they can supply me with?  Really interested in the component layout.  It would be greatly appreciated. 

-  As for the filter caps, the original manual shows 3 cans in a row, whereas the pic on pg 101 of Mr Hobbs book shows the caps in a diamond pattern- the same as the holes in my chassis.  Would it be correct to assume that both layouts were used? 

-  Rechroming...Is there anyone in particular that you have sent chassis out to and can recommend?  I do have some local guys but I have not been happy with their quality in the past.  I particularly worry about the aluminum output transformer cover.  Plating aluminum is not for the faint hearted.  And I don't know if they can strip the old plating on the aluminum without damaging it. 

-  I assume that the cap cans were also chrome.  Can anyone recommend a source for cans that are original looking?  I assume that I would have to have them chromed with the rest of it. 

-  The power transformer and the chokes...Is it chrome covers that come off?

Thanks for your time.  I greatly appreciate it.

Scott

[Norman S Braithwaite]

For starters all of the transformer and choke cover components should be steel, not aluminum. Check them with a magnet. The filter capacitors were arranged in a diamond pattern for the early Philharmonic sets and a line for the later sets. The aluminum filter capacitors were polished and lacquered on the earlier sets, not chrome plated. I don't believe the filters were polished and lacquered on the later sets. Also, the earlier Philharmonic power amplifiers had a power switch mounted to wires passing through the chassis with the power cord. This switch was mounted near the back of the cabinet on the right side. Later Philharmonic receivers had the power switch on the back of the volume control. The four pin switch plug was used with the later sets.

Norman

[Scott Seickel]

OK. So the Scott advertisement I refer to on pg 101 shows the wrong amp chassis for the FM radio it is with. I did not know if there was some overlap. I am just guessing that the cylindrical output transformer cover is aluminum because the covers on the tuner chassis are all aluminum.

Thanks,
Scott

[Norman S Braithwaite]

Scott: I misspoke! The cover over the driver transformer (output transformer is located in the speaker pedestal or on a crossover chassis) is usually aluminum and is a problem to rechrome. The covers over the power transformer and chokes are steel. I have seen some decent rechromed aluminum shield cans but they are expensive to rechrome and I have seen many that did not come out good enough to use.

Scott ads often depicted chassis variations differing from the product that the customer received. I suspect they provided their ad copy before the products had been completely developed. I cannot recall seeing an AM-FM Philharmonic with the filter cans in the diamond pattern but I have not paid particular attention to this detail.

Norman

[Kent King]

Norman & Scott -

That was something Marvin Hobbs and I once discussed....he confirmed that they would just grab components...sometimes even incomplete sets...and put covers and shields in place and then photograph them for ad copy. So no, you cannot trust advertising photos entirely when doing restoration work.

Kent


Norman S Braithwaite said:

Scott: I misspoke! The cover over the driver transformer (output transformer is located in the speaker pedestal or on a crossover chassis) is usually aluminum and is a problem to rechrome. The covers over the power transformer and chokes are steel. I have seen some decent rechromed aluminum shield cans but they are expensive to rechrome and I have seen many that did not come out good enough to use.

Scott ads often depicted chassis variations differing from the product that the customer received. I suspect they provided their ad copy before the products had been completely developed. I cannot recall seeing an AM-FM Philharmonic with the filter cans in the diamond pattern but I have not paid particular attention to this detail.

Norman

[Scott Seickel]

I got a price today on stripping and plating the amp chassis.....$450 without doing the aluminum transformer cover. This guy has been around many years and does good work, he just does not do aluminum anymore. Have to admit the price shocked me. I always thought that chrome was relatively inexpensive...but he says there is so much labor in polishing the chassis to remove the small rust pits once the existing chrome is removed.
Has anyone made reproduction transformer covers?

[Norman S Braithwaite]

The inside bends on the transformer shrouds are very difficult to polish. The quote you received is consistent with what I have had to pay here in California. Typically I am charged around $200 for the chassis and around $15 per small part. There are fifteen small parts on the power transformer and chokes. I am not aware of anyone making reproduction power transformer or choke cover parts but there is presently a discussion about reproduction coil and interstage transformer shields on Antique Radio Forums (http://www.antiqueradios.com/forums/viewtopic.php?t=65941). Incidently, if you are filling the added holes, do not braze with brass, fill with steel weld. The brass will polish away easily and leave a pock mark. After welding, the steel around the weld will be hard and difficult to machine but it will still grind and polish flat. If large holes are to be filled, special measures will be required to minimize warping.

Norman

[Scott Seickel]

In a rather bizarre turn of events, I had the amp chassis in the back of my truck, bringing it to the plating shop to get an estimate. I pointed it out (the amp chassis) to the guy who helped me bring all this radio stuff down from the old house attic a year and half earlier. I told him that this is the chassis (amp chassis) that I was looking for and was missing. He turns around and tells me that there is another attic area in that house that has more stuff just like the amp chassis we were staring at. He says he discovered it during the summer when he was at the house cleaning up. (Gee, when was he going to tell me!!!) It seems that there is a very low, but large, attic area over a newer (for the house anyway) addition that you need a ladder to reach. There is a little door in the gable end of the house about 15 feet off of the ground. Needless to say, I nearly wet my pants and speed to get a ladder and go over to the house. Thank God it (the house) has not been knocked down yet...I climb the ladder, open the hatch door and what do you know? The original amp chassis is staring me right in the face!!. I cleaned the whole attic out. It is only about 30" tall in the center, but it is quite large with a wooden floor. I did not find the tweeters I am missing but I got probably a 1000 to 1500 NOS tubes 90% radio numbers. The tubes were stored in metal boxes that preserved them quite well. I am attaching a couple of pics of the amps together. As you can see the original amp needs a rechroming also, but at least it is complete. I hope to be sending this chassis to the plating shop tomorrow.

[Scott Seickel]

Quiet here,  so time to update.....

I dropped these amp chassis off to the plating shop in late November.  I was told they would be ready before Christmas.  I still don't have them and several phone calls went unreturned.  So I took a drive to their shop today.  Looks like the plating is coming along nice.  Most pieces were done and they were working on buffing one of the chassis.  Hopefully next week. 

They were having problems with the 2 aluminum transformer covers.  They showed me one that they had nickle plated, and the nickle was peeling off.  Looked just like the chrome "bubbles" you see on many of these covers.  The owner told me that they were going to strip them and try again.  Seems that they either were not completely stripped the first time, or there are some inclusions in the aluminum that are not allowing the chrome to adhere.  One of the shop workers pointed out very tiny pin holes in the aluminum covers that he said were probably harboring some contaminants.  Pretty sure he said that when they get the nickle to adhere then they were going to copper over them to fill in any pits and imperfections.  This shop does a lot of aluminum plating and should be able to get these covers done.  Fingers crossed.  Then it will be time to learn how to rivet.  Norman was kind enough to share some of his rivet stash with me. 

 

 

[Leonid Soloviev]

Interesting story.

Thank you for update.

Leonid