Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5

Philco 41-608 connector question.
#16

Hi Harlan,

The 42-1015 I am currently working on uses a 32-8196. Nostalgia Air has the schematic for it: http://www.nostalgiaair.org/PagesByModel...013499.pdf The transformer is part 97. I'll try to remember to check the resistances on my transformer tonight.

Sean
WØKPX
#17

Thanks Sean,

I will take a look at it and try figure it out. Most likely I will need a tip on modifying this to
work with mine.

Thanks again,
Harlan
#18

Well, upon reviewing the diagram and rechecking my measurements, I see that the "common" side of the RCA connector is tied to the low side of the primary. The "middle" of the primary is connected to the "hot" terminal of the RCA connector. The top end of the primary seems to connect to nothing since that pin shows nothing tied to it If I'm seeing it correctly.

The secondary of this transformer has the low end also tied to the common of the primary and to chassis ground via the connector when plugged into the chassis. The upper end of the secondary is connected to the grid of the amp tube via a .002 cap.

Since the cable assembly I have is just a broken, cumbly uneven cable, should it be OK to just remove those two pair of wires and put in a couple lengths of light gauge mike wire. It would be a shield and center conductor. Since this application has the shield and common wire basically tied together by being connected to ground, would that work alright?

I would think I could just diregard that upper lead of the primary since it goes nowhere. Maybe I have this wrong so would appreciate any help you could offer.

I think I will just "hardwire" the end that goes into the chassis since there is no mating connector there... just has that "Motorola" type jack on the chassis (guess I would tie the "hot" side of the secondary to that jack center terminal).

Thanks again for any help...
Best regards,
Harlan Icon_smile
#19

I would think that shielded microphone wire should be fine. The scan on Nostalgia Air is rather poor. The top side of the primary is connected to one pin of the 4-pin connector on the transformer. So, the signal from the photocell on the phonograph connects to the primary of the transformer (two closer spaced pins). I think the RCA jack is for connecting a microphone for the home recording option. The 1941 BOL units have a bayonet lamp socket on the transformer where the microphone plugs in.

Sean
WØKPX
#20

Thanks Sean,
First I thougth I was "getting" this but now I find myself further confused.... I'm getting pretty angry about now cuz I'v started this reply 3 times and spent about 10 minutes typing each time. Then I saw an error and was going to correct it only to find my entire message went poof ... for the THIRD time!

First I would like to review what I have here on this 1941 model.
On the back of the cabinet is a terminal strip with two screws and a female RCA jack. The two screw rear
terminals have a wire coming to them from the tonearm. Then a pair of seperate wires come from the top
of the chassis and via spadelugs, connect to the two screws providing the power for the BOL lamp.

The back side of the RCA connector had a pair of wires also from the tonearm which are from the photocell
and go via a cable to the transformer primary(not sure of the termination at the transformer since mine is
missing). The the output of that transformer (secondary) went into the back of the chassis via a "Motorola"
type connector (like old car radio antennas used). From here the wires connect to the input of the preamp tube.

Now on this 1942 model (sorry didn't recheck the drawing) is the lamp powered the same way with the two wires
from chassis to the terminal strip?

I don't get from the drawing, where is the tonearm connected to this layout? I thought that length of cable illustrated
(the horz lines) with the 4 pin termination at each end was showing that it connects to the transformer's 4pin connector.

Sorry, I'm lost on the flow and interconnetion here somehow. Also (mine doesn't have it) how was a recording made with
this layout? A Seperate arm maybe had an electromagnetic device in it which vibrated into soft plastic which later hardened for playback? Was the signal going right from the mike into the transformer primary ... and then the secondary here shows going to the preamp.. how can that work? ... sorry I don't get it.

Pardon the denseness on my part... just lots of bits and pieces and I'm not seeing it correctly.

Thanks for all the help.... frustrated and confused Icon_redface Icon_confused Icon_smile
#21

I understand your confusion. The 1942 phonographs are completely different animals from the 1941 models except for the tonearm. Here are the interconnections for the two model years (if I remember the 1941 correctly):

1941:
Two wires come directly out of the chassis and connect to the screw terminals on the rear of the phonograph shelf. These are for power to the tonearm lamp. There is an interconnecting cable with the Motorola style plug that plugs into the jack on the chassis on one end and into the transformer on the other end (I don't remember what the connector was but it may have also been a Motorola style). There is a cable hardwired into the transformer on one end with an RCA style plug on the other end that plugs into the RCA jack on the back of the phonograph shelf. This is the audio from the tonearm photocell.

1942:
There is a 4-conductor cable hardwired into the chassis with a 5-pin (only 4 pins are used) speaker connector on the other end. This contains two wires to power the tonearm lamp and two wires to bring the audio from the photocell back. In the middle of this cable is the smaller 4-pin connector that plugs into the transformer. The audio from the photocell goes into the primary of the transformer and comes out through the secondary that is connected to the radio.

So, what you would need to do is come from the RCA jack on the back of the phonograph shelf and go into the primary of the transformer (two closer pins of the 4-pin connector on the transformer). Then come out of the secondary of the transformer (two further separated pins of transformer connector) to go into the Motorola jack on the back of the chassis.

The home recording unit has a crystal cartridge with a cutting stylus. The stylus actually cuts the groove and audio into the surface of a blank recording disc. The audio source can be either the radio or a microphone that connects to the jack on the transformer. In the case of the microphone the audio is passed through the transformer into the phonograph amplifier and then to the audio output tubes. The audio is pulled off of the output transformer to drive the recording cartridge.

Sean
WØKPX
#22

Excellent, E-x-c-e-l-l-e-n-t...EXCELLENT explantion, Sean !!! Icon_biggrin

That helps tremenously. Yes the drawing is confusing so am just going to go with your explantion and wire
it accordingly. That diagram apparently also isn't showing the record capable version.

Just going to take a length of cable with an RCA connector on the end and wire it into the 4 pin plug
that I bought (the crusty old grungy chunk). Then take a piece of light mike cable and wire one end
into the jack (wide spaced pins) and put a Motorola plug on the other end to go into the mating
connector on the back of the chassis.

I will just do the lamp power leads the way they were unless I need to modify something else.

Hopefully this will work out well especially since this isn't the original transformer type... otherwise
may have to "punt" and find another method.

Again, thanks very much! Icon_biggrin
#23

New member here, with exactly the same situation - 41-608 was missing its original BoL changer, but I picked up one from a different set, complete with 32-8196 transformer. @Harlan: I was wondering how your re-wiring job went, and whether you got the changer working. I don't want to "re-invent the wheel" if the end product doesn't work Icon_biggrin

Thanks in advance,

Brian
#24

Hi Brian and WELCOME !

I haven't been a very faithful member for which I apologize. I finally got through my "rebuild" with lots of help from the fellows on this
forum and sorta dropped out after that.
Happy to help if I can... I took the BOL changer apart pretty completely except leaving some of the linkages still connected and then
thoroughly cleaned every inch of the base and the parts. It was pretty gunky to say the least. Sorta looked like a lost cause at first
glance. I didn't even try to operate it before starting in on cleaning it up cuz I figured if anything wasn't behaving correctly, it could
be likely due to it's bad condition.
I won't go into all the detail but once I got it all back together and tried it, the motor ran and the turntable turned and it sorta went
through a change cycle. It wasn't completing the cycle or "setting down" the way it should. After rechecking my work as well as I
could, I didn't really see any clear answer. So.... I bit the bullet and sent it off to the fellow (name escapes me now) that rebuilds
these. I needed the "tone arm" replaced cuz mine was cracked (metal near optic stuff was broken) and figured I'd have to get a
replacement for that anyway.
Well he got it working but apparently I had only one minor error on reassembly that caused my trouble and, of course, he supplied
a working "arm". Once it was all placed into the cabinet and connected up it worked well except for a couple minor tweaks.

The replacement transformer (different than the original) worked out just fine and wiring it was pretty much like the discussion
above relates.

Hopefully this is some help to you but if you need more clarification, feel free to ask and I will try to help.

Oh... the fellow that works on the BOL changers is "Gib" Epling and operates as West-Tech Services
Web site: http://www.west-techservices.com/




Users browsing this thread: 2 Guest(s)
[-]
Recent Posts
Shadow Meter Bulb
Phorum members, I am trying to find the bulb # for PHILCO Shadow Meter part number 45-2180 that is from a 37-640 chassis...georgetownjohn — 06:53 PM
Philco 41-608 changer coupler
3D-printing...short of machining, of course. Or molding.morzh — 05:20 PM
Philco 41-608 changer coupler
Thanks, Morzh. That solves the issue of the rubber pieces. Now, I need to find a way to replicate the pot metal piec...alangard — 05:07 PM
12' Philco
If it is 12', either Kareem or Andre would have to jump pretty high to look at the front panel. Kareem would have an e...morzh — 01:48 PM
12' Philco
And here's a story about the tires on the truck. Same "no-stoop" guy must have installed these! Take care a...GarySP — 01:17 PM
Hickok AC51 tube tester
I think they have only shown the secondaries of the transformer. Two of them feed the rectifiers' filaments.morzh — 12:58 PM
IF can wire size and Rubber mounts?
Arran If the wire inside cans is the gauges you mentioned, the sole reason for that would be mechanical, to stiffen t...morzh — 12:56 PM
12' Philco
Rod, Yes, I know, but the Giant Philco is not around anymore either, so I go by whoever was alive fairly recently. H...morzh — 12:54 PM
Hickok AC51 tube tester
Absolutely no one is going to reverse engineer that circuit. Even the iron core is missing.RodB — 10:37 AM
IF can wire size and Rubber mounts?
Thanks to both members for your help regarding wire and tuner mtg supports. regards--Johngeorgetownjohn — 09:33 AM

[-]
Who's Online
There are currently no members online.

>