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Philco 41-608 connector question.
#1

Hi
Working on this radio and wondering about the purpose of a 3 pin connector on back of chassis.
It appears to accept a mating connector of 3 straight pins. On the schematic if you were to look
just beneath the loop antenna connector you will see what I'm referring to. Looks like one pin
is ground, one goes to one of the leads from the loop antenna and the third to the antenna coil
on the chassis.
I'm guessing this is for a "long wire" type external antenna. Would this be used for both SW and
AM broadcast benefit? Is the built in loop also for both SW and AM? Would you just attach an
insulated lead wire to the upper pin and run the wire inside or outside for improved signal?

This unit has the record player built in as well. Things have been missing so not clear on how some
of this stuff was connected. Now on the chassis back is another connector that looks like the type
used in car radio antennas years ago. This must be the audio input from the phono. On a wooden
brace in back of cabinet there is a terminal board. On one end there is an "RCA" type connector which
must be the phono output to the radio/amp. So... one end uses the "car radio antenna" connector and the
other the RCA type. Could one just take some two conductor shielded cable and make up the cable
with appropriate connectors? Also that terminal strip has two screw terminals which must accept the
loose wires from the chassis which I have traced to (1) ground and (2) to the rotor of band switch.
If I'm reading it correctly, this switches in a part of the "OSC" coil when in Phono posistion but I'm
not clear of the purpose. Could someone help on these questions?

One more... where would you suggest I get the speaker re-coned? (12 inch)

Thanks very much!
Harlan Icon_biggrin
#2

Hi Harlan,

I believe the 3-pin socket is for an external antenna.

The auto antenna style jack (I think this is a Motorola style but I may be wrong) is the phono input. The RCA jack is for the output from the phonograph. Your radio should have the Philco Beam-of-Light phonograph in it. This phonograph used a lamp that reflected light off of a mirror attached to the stylus. A photo-cell received this light and converted it into the electrical signal to be amplified by the radio chassis. The lamp was powered from the oscillator running around 500KHz or so since 60Hz would be picked up by the photo-cell and would be heard in the speaker. There is also an audio transformer in a black case mounted inside the top of the cabinet to the left of the chassis when viewed from the rear. The cable that plugs into the RCA jack goes into this transformer and the cable with the auto antenna plug comes out of the transformer. I have attached a photo of the rear of a 41-608 I restored a couple of years ago. Oh, and the octal socket on the rear of the chassis is for the optional HR-1 home recording unit that could be installed onto the phonograph.

For the speaker I would recommend Hank Hank Brazeal in Alabama. I have had him do a couple of speakers and he does excellent work.


Sean
WØKPX
#3

WOW ! Thanks for the quick reply, Sean.
I hope you don't mind a private message. I'm very impressed with the photo of the
radio / phono you have that is like the one I'm working on. No, I'm pretty sure that
transformer you mention is not inside the cabinet of mine... I'm not at my shop now.
Would this be available somehow?

Would you mind looking at and commenting on my two earlier posts on the same forum?
I guess it should have gone under "electronic restoration" instead of where I put it... wasn't
reading closely enough, I guess.

Anyway the two topic questions also list this model. One question includes photos of the
moving dial lamp "band indicator". I'm not sure how this should be "strung". Maybe a photo
of your working unit would enlighten me and clear that up.

My other post was about the replacement volume and tone controls I put in and how they
behave plus some other questions.

Sure would appreciate your help and comments as it seems no one else has responded and it
has been a few days but I know how it is... so glad you replied and hope you won't mind if
I ask a few more questions as my project unfolds..

Thanks again and I apologize for not handling or knowing how some of this posting,
emailing should be done on the site... you may email me directly at hpgarbe@charter.net.

P.S. Duh,,, I wanted to send this as a PM but for the life of me, I cannot see where to "send"
the message... it shows up as (1) one message in my "Outbox" on the board but nowhere do
I see a way to "send" or "submit" it to be privately sent... sorry again so hope you can help me
on this as well and sorry it had to show up here as that was the only way I could see to get to
you. My humble apologies.

P.P.S... yet another thought. I checked inside the cabinet and ... there were only 4 screw holes
where that transformer may have been ! Again, is there a possible source for this?

Thanks again and best regards!
#4

I'll move this and your other topic to Philco Electronic Restoration for you, Harlan. Icon_smile

Please see the Announcements section - I've just posted a tutorial on how to send private messages (PMs).

While you are of course free to take your conversation private, I hope you will leave it on here - others may benefit from the discussion on this subject.

Thanks.

--
Ron Ramirez
Ferdinand IN
#5

Hi Harlan,

You might be able to find a transformer as I would imagine they used this same transformer on numerous sets with the beam-of-light phonograph. Does your set still have the beam-of-light phonograph in it? If it doesn't then this transformer probably wouldn't do you any good. The transformer is item 54 on the schematic.

I sold my 41-608 about two years ago and I didn't take any photos that show the band indicator lamp. I don't remember well enough how it worked to be able to help you out.

Sean
WØKPX
#6

OK Sean... Thanks for the info. Yes, the record changer is still in the unit although in horrible shape.
Thanks for clearing that up about the transformer... I just didn't really pay close attention to that
item on the diagram...was somehow dismissing it as maybe some small coil under the chassis I had
missed.
Do you know of any suppliers that may have such a part as the transformer? Suppose it is too special
to find anything generic to make it work like the original.

Thanks again for your help.
Harlan
#7

I looked through the listings at Play Things of Past but could not find this transformer. They have one from a 42-1008 that also used the beam-of-light but I don't know if it would work. What you need is part number 32-8135. The one at PTOP is 32-8196.

Sean
WØKPX
#8

The 42-1008 transformer (32-8196) should work in the 41-608. I could not find specs on the 32-8196 transformer, but the circuitry for both models is basically the same.

--
Ron Ramirez
Ferdinand IN
#9

Ron and Sean.. thanks.

I guess you are referring to (on OldRadioParts.com) the transformer page
(misc. catagory) where the number in the far left column (stock number) is 1330-033
and shows the following line:

1330-033 UNKNOWN PHILCO 32-8196 1.5K TO 100 OHMS D.C., METAL CAN, .USED 1 2 3/4 2 3/4 2 0/0 2.50

So you are assuming this should work in place of the 32-8135 ?

From Sean's photo and looking at the upper left corner of the cabinet, one can see the black item with the
cable with "Motorola" ends on it. This would be that transformer then but the dimensions given on the part
(in line above) seem like they would be for something smaller???? 2 3/4 by 2 3/4 by 2. What are your thoughts?

By the way, where do you guys find the list of part numbers for the models? Probably some material I don't have
"free" access to on-line? Thanks for checking it out for me. Guess I will be getting up an order to that fellow and
scrape up several more things to get the $20 minimum.

Hope you can get back to me to confirm this once more... many thanks!
#10

I would think that you could make the 32-8196 work. It is wired as a standard primary-secondary step-up transformer where as the 32-8135 is wired as an auto-transformer step-up transformer. There might be some impedance matching differences but it may not be noticeable. I was referring to OldRadioParts.com. They also list one as stock number 4573-040 in the input transformers list. It seems to me that the transformer was larger than the dimensions they show. I have a 1942 Philco with the beam-of-light at home that also has a transformer that I believe was about the same size as the one in the 41-608. I can measure the dimensions and let you know.

For the part numbers I get them from the service information. This is shown on the Rider's available on Nostalgia Air but I also have the 1941 and 1942 Philco service manuals that are much more clear than the scans on Nostalgia Air.

Sean
WØKPX
#11

The transformer in my 1942 model is also a 32-8196. The dimensions match those given on the Play Things of Past web site. This transformer has a 4-pin plug sticking out of the top. I don't think the one from the 41-608 had a 4-pin plug like this but I could be wrong. Either way you should be able to connect onto the pins for your connections.

Sean
WØKPX
#12

Thanks for all the help. I have another lead to follow up as well. WesTech Services fellow said he may have the original type transformer. He hasn't confirmed it yet. I was telling him I may need his help in restoring the Beam of Light turntable.

Again... do apprecaite all the help and support from you guys. Best regards, Harlan
#13

Well that other lead for a transformer isn't real promising. He would like a quite a lot of money for it so I'd like to try plan "B".

First I checked out the Rider's on Nostalgia Air again and yes, there is a parts list on the model 42-1008 but I did not see one at all on the 41-608. I checked a few others as well and some did and some did not have parts list (with part numbers).

Would anyone know which models in the 41-42 era had the Beam of LIght phono with it so I could go through a number of the diagrams looking for those with part numbers and see if another used that autotransformer style that might have a different part number which, if it were available, might more closely match the one I need.
I don't suppose there is any way of knowing what the ratio of this transformer is/was so as to be able to just pick out a possible genaric transformer and just make up your own connectors for it.

Why do you suppose they used that heavier cable with Motorola connectors on it to go to the chassis input rather than
just another RCA type connector as is used on the phono side of the transformer? Surely it is minimal current involved.

Anyway... sorry to belabor the point but that Rider's manual for the 41-608 doesn't show a part number list... if you find it could you note a "link" to it for me to click on to view it?

Does anyone know approx what voltage level was put out by that Beam of Light tone arm?... would it be like a ceramic
cartridge or more like a magnetic which is a very weak level?

Thanks for now.
Harlan Icon_biggrin
#14

Harlan,

Here are the 1941 models with the BOL pickup that I come up with from the service book: 41-608, 41-609, 41-610, 41-611, 41-616, 41-620, 41-623, 41-624, 41-625, 41-629. The 41-608 through 41-611 use the 32-8135 transformer.

I looked at the Rider's on Nostalgia Air and you are right, they do not have the parts list. I have the service info for the radio, changer, and home recording unit scanned as PDFs. Send me an email and I can send them to you. seanbart at fidnet dot com.

You should also check out Chuck Schwark's page about the pickup. According to the chart on that page, the photo cell puts out about 42mV with 3V on the lamp so it is a pretty low level signal.

Sean
WØKPX
#15

Well, I purchased the 32-8196 input transformer from "Playthings of the past". To review (or read earlier posts in this thread), I'm going to have to try and substitute this transformer for the one that is normally used in this radio for the phono input since the exact one is not availble at a reasonalbe cost.

The problem I'm seeing is this. This 32-8196 has one RCA jack on it's top plus a 4 pin type connector as well. The resistance read across the RCA connector is only about 1/2 ohm or so. The resistance across one pair of the 4 pin connector is about 105 ohms and the other pair is about 1.6k ohms.
I'm not sure what the meaning of these readings is. I thought there was going to be a primary and a secondary but seems we have three isolated windings. There is infinite resistance from any winding to any other so can't be any type of autotransformer either. Then I also got this pigtail old cable to connect to the transformer. It has a 4 pin plug that fits the connector on the transformer and two sheilded leads coming out of it with bare wire ends. Each pair of wires has a copper braid wire around them.

I assume the RCA connector (winding) from the transformer would connect to the RCA connector on the terminal strip on the back of the cabinet which then goes to the tonearm "cartridge" (BOL output). But... what is to be done with the other two pairs of lead wires from the transformer? On the 41-608 diagram the common or shield side of the autotransformer is at ground and the other lead goes to capacitor #51 (.006) which is on the grid of the preamp tube.

Does anyone have a diagram of the model that uses the 32-8196 transformer to identify what is done with that 4 lead set of wires from the transformer?

Any help will be appreciated ! Icon_confused Icon_smile




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