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 Post subject: Fun with a Philco 37-630....
PostPosted: Oct Fri 25, 2019 3:06 am 
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Location: Cottage Grove Oregon; 97424
Well maybe not that much fun....I was asked by a lady in Church if I could "look at her old radio she has had since she was a kid." and it just quite recently.
Well I noticed that it has been worked on in the past, long ago past most like a real Philco dealer because they only disconnected two of the electrolytic s, and used real Philco parts. They used electrical tape that was still of the cloth variety. They even left one of the original Wet type electrolytic s installed and hooked up. When I tested it is was still putting out 16 MF and still full of liquid.
Well the tar and nicotine is a nightmare to clean off, so if any of you folks know a great way to get that stuff off I would love to know.
I recapped the whole radio except two paper caps under the band switch area that I will have to see about how to remove the center "island" section of the chassis. I get 310, and 201 volts DC on the Eletrolytics and all tubes are now good, two were bad. There is just so much on the schematic and or the radio that is not on the schematic, now I know about running changes but some things just do not line up from the picture that in on one page and the actual schematic on the other.
All I get when I power the radio up and try the various bands is just a quite hum. If I touch the grid cap of the 6Q7 then there is a lot of loud buzzing hum as well.

The candaohm is not like the one pictured on the schematic and the ohm readings do not match either.

Nostalgia air does not have the schematic but Radio Museum shows Riders manual 7. So that is where I found it.

Sorry I don't have a link. If any of you folks know a "easy" way to remove the center "island" section of the chassis without hiring a brain surgeon to change out those two caps or removing all the coils in one section please let me know. Thanks, and God bless.


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 Post subject: Re: Fun with a Philco 37-630....
PostPosted: Oct Fri 25, 2019 4:11 am 
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Good evening,

I worked on one of these several years ago. Removing the RF sub-chassis is not trivial. Going from memory, you need to disconnect something like 13 wires that connect between the two chassis. Then there is a bolt on the center of the back of the chassis, you will need to remove that. Then even with all of that done, you still have to tilt the RF chassis forward while you pull it back and out. Complicated to explain and a lot of work to finally get it free, but it does come out.

Once you get the RF chassis out, you can remove the side walls to give you better access to those caps that are hidden way up under everything. I remember those caps being very hard to get to even after doing all of the above... and then you get to reverse the whole process and put it all back :(

Not sure if it will help at this point, but I have a PDF of Philco Service Bulletin #251 that I found online somewhere. It includes a relatively clean copy of the schematic, a parts layout diagram, and alignment instructions in one 4 page document. PM me your email address if interested, and I will send you a copy.

Good luck!
Jon


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 Post subject: Re: Fun with a Philco 37-630....
PostPosted: Oct Fri 25, 2019 2:37 pm 
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Joined: Sep Sun 08, 2013 6:34 pm
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Location: Lehigh Valley, Pa
I prefer to remove the sub chassis for repairs... and it is a PITA. However, I have also loosened the center chassis and removed the side curtains and worked "sideways"... was a bit quicker, but a bit more tedious. I was always told the mark of a smart mechanic is how much he doesn't remove to make repairs... not sure if I agree... This would be a good application for homemade Sprague "kwikettes" or "quigs"... see: viewtopic.php?f=19&t=216079&hilit=sprague+quigs
YMMV!!

Jim

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 Post subject: Re: Fun with a Philco 37-630....
PostPosted: Oct Fri 25, 2019 5:09 pm 
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Generally, I think at least some disassembly is the right way to go. It makes cleaning and inspection easier, provides better access for part replacement, etc.
Simply take pictures, make notes, and--during reassembly-- check everything against the schematic.**

I do lot of German sets, and I routinely remove the piano switch assemblies for cleaning, lube, testing, etc. After doing a few of these, I regard a Philco as a vacation.....:)



**Personal bias only: If you are not comfortable with using a schematic, don't attempt anything significantly more complex than an AA5

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"Measure voltage, but THINK current." --anon.


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 Post subject: Re: Fun with a Philco 37-630....
PostPosted: Oct Sun 27, 2019 2:42 am 
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If the new caps don't improve performance, what would your next move be?
I think check voltages and determine if the oscillator stage in the front end is working.

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 Post subject: Re: Fun with a Philco 37-630....
PostPosted: Oct Mon 28, 2019 2:08 am 
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I didn’t have to remove any wires when I repaired a 37-630. I unbolted the two side sections from the center and avoided cutting any wires. Look at the picture about half way down this post; https://www.antiqueradios.com/forums/vi ... hp?t=97925


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 Post subject: Re: Fun with a Philco 37-630....
PostPosted: Nov Wed 13, 2019 2:39 am 
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Location: Cottage Grove Oregon; 97424
Well I know it's been awhile since I last posted, I did a lot since then, pulled the RF center section made some new rubber gr omit thingy for the center section, changed out some bad wires tested tubes replaced two, and cleaned, cleaned and more cleaned. That tar and nicotine staining is horrible! I had to put the tuni9ng section in the sonic cleaner. So I put it all back together and low and behold there is one wire I can not remember where it goes! and it's not on any of my photos. just my luck. So I am posting a couple of pictures maybe you radio guru's could please help me out??
Thanks, and God bless.
I know that the wire comes from the center section of the RF section, I posted a picture of the band switch section where it comes from the "C" section. As soon As I find the other photo I'll post that as well.


Attachments:
Kohler engine2.JPG
Kohler engine2.JPG [ 120.63 KiB | Viewed 711 times ]
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 Post subject: Re: Fun with a Philco 37-630....
PostPosted: Nov Wed 13, 2019 2:57 am 
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Location: Cottage Grove Oregon; 97424
You can see the wire in the photo it's longer than it has to be the original wire was only about an inch and a half long. It is the yellow wire sticking more or less straight up. and comes from the "C" "D" section of the band switch.


Attachments:
philco 37-630.JPG
philco 37-630.JPG [ 185 KiB | Viewed 702 times ]
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 Post subject: Re: Fun with a Philco 37-630....
PostPosted: Nov Wed 13, 2019 5:04 am 
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Hi,

I have countless photos of my restoration, and I have another in the garage yet to do. I'd be glad to look and send you my photos, but I can't tell which wire you are referring to in your photo.

Steve


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 Post subject: Re: Fun with a Philco 37-630....
PostPosted: Nov Wed 13, 2019 1:46 pm 
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Mike;
You might be tired of hearing this but....we cannot normally diagnose problems based on pictures of the wiring. In my opinion, there is no substitute for comparing the wiring to the schematic.

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"Measure voltage, but THINK current." --anon.


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 Post subject: Re: Fun with a Philco 37-630....
PostPosted: Nov Thu 14, 2019 10:02 pm 
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I reviewed my notes from when I worked on mine.

If I am correctly understanding which wire you are talking about, it seems to be coming from the center (or RF) section of the sub-chassis. I had two wires that came from that section of the sub-chassis, both of which connected to the long terminal block mounted along the right side-wall of the main chassis. In my pin numbering scheme for the terminal block, I only counted the pins that were actually present, starting with pin 1 toward the front of the chassis, and going to pin 12 near the rear.

One of the wires from the RF section of the sub-chassis connected to pin 2 of that terminal block.
The other wire connected to pin 10 of the terminal block.

I agree with Mark that you should confirm these connections against the schematic before soldering and certainly before powering on.

Jon


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 Post subject: Re: Fun with a Philco 37-630....
PostPosted: Nov Fri 15, 2019 5:16 am 
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Location: Cottage Grove Oregon; 97424
That's just it, the schematic is SO confusing with the whole c1 c2 d2 d3 ect and going to all these different points on the actual switch wafer.

The original wire was short and not nearly as long as the yellow wire is now as several inches. I know it did not go to a tube pin. That section is in the short wave band....so maybe I don't even need it??


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 Post subject: Re: Fun with a Philco 37-630....
PostPosted: Nov Fri 15, 2019 11:25 am 
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A wire has a finite length so that limits possibilities. A wire has an origin, so if one looks at the point of origin, they can normally work out where it was headed.

I was not endeared to a Philco recently, fairly compressed assy. However, The oscillator coil RF end had to come out to get the tube socket out. Much scope for error. In this cases there were several photos of the area prior to attacking it to show where one group of wires came from then strategic dobs of colour. Then more photos with the coil out.

As all of the resistors on the socket were out of spec they were left on the socket & cut such that the tail was still where it came from but at a different length, so that it was obvious when compared which resistor etc. was on which pin.

A little bit of forward planning can save heaps of hair & time later. Senior moments can wreak havoc.

Marc


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 Post subject: Re: Fun with a Philco 37-630....
PostPosted: Nov Fri 15, 2019 12:32 pm 
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Pick any random feature in a chassis---a wire, a component, a switch terminal. Whatever you are looking at will be associated with a node. What is that? A "node" is the junction of 2 or more branches in a circuit and has 2 simple rules:
--every physical location on a node is at the same potential.
--the sum of the currents in and out of a node must be zero.
Physically, a node can be all over the place. The best example is maybe the chassis, but things like filament wiring and the B+ or AGC busses are spread physically throughout the structure.

For anything that you observe in a chassis, you can find it on the schematic in a few basic steps. First, determine if it is a "global" function such as the chassis, B+, etc. One very common pitfall is identifying something as "connected to pin 7 of the frammus tube", when the important attribute is that it is connected to the chassis.
Once you have identified a node on the schematic, then find everything that is supposed to be connected there. If the schematic shows 4 branches from a node, and you can only find 3 of them, then investigate further.

Don't try to find everything connected to the chassis---in this case, go the other way: when you are identifying branches from a node, and one is supposed to go to chassis or some other global node, all you need to do is verify that that happens.

Finally, when it's time to seek help:
identify the relevant nodes on the schematic. If you're not sure of something---eg switch wiring--give some kind of unambiguous description.....Example: "The terminal on the bandswitch where the capacitor connects from the oscillator grid"----not a complete description of the node, but at least unambiguous.....

Avoiding ambiguity is crucial.....here are some things NOT to say:
"connects to the red wire from the oscillator coil"
"connects to a terminal with 2 other wires"
"connects to pin 5 of the frammus tube" when that is an unused pin being used as a tie point

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"Measure voltage, but THINK current." --anon.


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 Post subject: Re: Fun with a Philco 37-630....
PostPosted: Nov Fri 15, 2019 1:49 pm 
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+1 with Pix. It is not an easy task fixing by correspondence. If you can use a program as simple as "Paint" then there is every opportunity to circle, or put arrows on it showing the specific feral wire.

Rather what I was getting at: Specifics. Trace the wire to its point of origin but then we need to know the specifics of the of pin or node. As Pix has noted, if it is connected to a dead pin, it could be anything, so one has to point that out and move to the next phase and see where it goes from there(?) and then identify what that node /pin is and refer back to the schematic.

Where there is a layout diagram that too can be a big help. Perhaps it would help, if on your schematic as you identify the wire on the schematic, colour the line on the schematic its colour. Even wire tracing needs a logical approach.

On wire often if it breaks away there will often be a pattern on the solder. On the subject of solder and soldering I am not overly exited with some of it. temp may be a bit cold?

Marc


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 Post subject: Re: Fun with a Philco 37-630....
PostPosted: Nov Fri 15, 2019 2:53 pm 
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I don't mean to throw a wrench into an already difficult thread, but are you sure that the chassis you are working on is a Philco 37-630 chassis? I looked more closely at the picture you posted on Nov 12th, and there are some significant differences between your chassis and mine. Sorry I didn't notice this earlier. Here is a picture of the underside of my 37-630.

Attachment:
My_37-630_Chassis.jpg
My_37-630_Chassis.jpg [ 490.04 KiB | Viewed 505 times ]


Your chassis does not seem to have most of the trimmer caps that mine does. I'm only offering this because the 37-630 is a difficult schematic to decipher, but maybe we're looking at the wrong one and the correct schematic might be easier to follow.

Jon


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 Post subject: Re: Fun with a Philco 37-630....
PostPosted: Nov Fri 15, 2019 7:26 pm 
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Someone over to the Philco Forum posted a photo of what appears to be the same chassis and wanted to know "Which version of the model 37-6(2)0 do I have?"

To my eyeballs,it looks like Mike has a 620 not a 630.I could be wrong...


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37-620 (a).jpg
37-620 (a).jpg [ 273.25 KiB | Viewed 489 times ]
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 Post subject: Re: Fun with a Philco 37-630....
PostPosted: Nov Fri 15, 2019 8:04 pm 
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In that case, ignore my notes about where to connect that wire.


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 Post subject: Re: Fun with a Philco 37-630....
PostPosted: Nov Fri 15, 2019 10:59 pm 
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Now we see the value of little comments like " Picture is worth a thousand words" and the picture.

It is like looking at my 1951 TE-20 Ferguson (Pre Massey Ferguson) Tractor. At a glance they all look the same and nothing could be further from the facts. American ones have Continental engines. The British two different bore sizes, Petrol engines diesel engines, Vaporising oil engines and Kerosene engines (will likely run on Jet fuel as is a Paraffin). Then its a British engine the 6V is different than a 12V and the hydraulic pump was same as Lancaster Bomber and so it goes on... :Specifics important for parts.

Radio's can be the same; umpteen different cabinets with the same chasses and umpteen different chasses in the same cabinet and production mods in the chasses during the run.

Think we need a good sharp photo of this one in the hope that someone may recognise it? That does not mean there is no hope of tracing the wire. It means more specifics on what it is still attached to including the tubes & its elements, where applicable.

Marc


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 Post subject: Re: Fun with a Philco 37-630....
PostPosted: Nov Sat 16, 2019 5:40 am 
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Location: Cottage Grove Oregon; 97424
It is a 37-630 per the sticker on the chassis, Riders Vol 7. That is where the similarities end. LOTS of things don't match the "Pictorial" in the schematic for the 630. For example there are two baklite blocks, and the candaohm resistor is different just to name two changes.

Gosh, I don't want to have to take out that whole section again...... :cry: :cry:


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