Philco 38-9 Switch

4/17/2012 9:13:07 PMrichard

Hi. I have recently taken out the on/off/tone switch out of my Philco 38-9. As far as I can tell it has four positions with position 1 being off. Position 2 shows continuity for the 2 bottom terminal lugs which I believe turns the radio on. Positions 3 and 4 continue to show continuity for the bottom 2 solder lugs but doesnt appear to have any effect on the top 2 solder lugs. Is my switch defective or am I not understanding something? If I were to order a new switch would the terminology be 2 pole 4 position? I'm new at this so any insight would be greatly appreciated.

4/18/2012 9:01:26 AMLewis L.

:Hi. I have recently taken out the on/off/tone switch out of my Philco 38-9. As far as I can tell it has four positions with position 1 being off. Position 2 shows continuity for the 2 bottom terminal lugs which I believe turns the radio on. Positions 3 and 4 continue to show continuity for the bottom 2 solder lugs but doesnt appear to have any effect on the top 2 solder lugs. Is my switch defective or am I not understanding something? If I were to order a new switch would the terminology be 2 pole 4 position? I'm new at this so any insight would be greatly appreciated.
:
Ridhard:
Yes, I would say 2 pole 4 position, with three of the power section jumpered so the radio will stay on while you change the tone with the other wafer.
Lewis

4/18/2012 8:00:53 PMrichard

Thanks for your help Lewis.I will order this type of switch tonight.

4/18/2012 10:35:22 PMEdd

Sir Richard. . . . .

I certainly don't have one of those chassis to eyeball the switch proper.

But in looking at the available photos on the internet, close up chassis pictures seem to show that control as being built, such as to resemble a common larger diameter volume control housing with a common switch mounted onto its end.
With it not being open wafer construction, such that you can see each of the individuial stationary contacts and the rotor.

However, in consulting the schematic, one would see the power switch function being a common SPST switch . . . . . and the long broken line angling up to the tone control switch is showing it as being mechanically ganged to the rotary tone control switch.

Would you be my eyes and confirm that your units actual power switch is a unit somewhat similar to the supplied photo at:

http://www.ebay.com/itm/Centralab-KR8-FASTATCH-SPST-Rear-Switch-Element-/190509902843

There are additional photos of AC switch variants at the bottom of the page.

Somehow I want to think that your switch is such that the extreme left rotation of the tone control shaft flips that solitary power switch off, or if you turn the tone control rotary shaft to the first position, the separate power switch is flicked on and stays on for ALL of the further cw positions of the tone shaft.

Come back to the 2nd position of the tone control and then the additional movement into position one . . . or tone control function off . . . will then also flick that separate power switch off.
BTW . . . are we having an intermittent or non functioning power switch problem, as I would expect no problems being had from the separate tone control function switch .

I suspicion your switch to be like one Johhny had problems with recently, I would give you that thread, but can't remember it nor locate it with out the sites SEARCH function, but it was with in the last 4 months . . . or so.

The perceived "work around" use of a dual section 2 pole 4 position rotary switch, could present a picked up AC hummmmmm problem if the AC wiring gets too close to the section used for the tone control function

Also, for the power switching function , it really wants to be a shorting type, make before break action, for the 3 wired together stationary contacts, otherwise AC power will be intermittently disrupted when switching between tone positions.(Unless you are a Speeeedy Gonzales, each time you switch. )

As for the tone control wafers section, it would be using a non shorting switching action in its wafer.

73's de Edd

The hardest thing in life to learn is exactly which bridge to cross . . . . . and which to burn..

:Thanks for your help Lewis.I will order this type of switch tonight.
:

4/24/2012 12:00:59 PMrichard

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:Hi Ed. Thank you so much valued input. I removed this switch earlier on and I will try to describe it as follows:

:There are four solder points where 4 wires were connected to each point. The bottom part of the switch is encased in hard plastic and has 2 solder points. I believe this is what turns the radio on. The top part of the switch is open wafer and has the other 2 solder points/contacts for the 2 tone controls. The extreme left position is the radio off position which shows no continuity across the solder points that turn the radio on which seems correct. As I turn the switch 1 click to the right I measure continuity across the two solder points that house the on /off switch and in the open wafer section I see this little metal tab slide between the first tone contact. At this point should there be continuity across the on/off solder points as well as the first first tone solder point/contact? I only see continuity with the on/off solder points but no continuity between the on/off solder points and tone 1 position even though the little metal tab has slid between the tone 1 contact. When I turn the switch 1 more click to the right continuity remains on the solder points that turn the radio on and I see the metal tab slide out of the tone 1 contact and rest between the tone 1 and tone 2 contacts. The final postion/extreme right of the switch continues to show continuity across the on/off switch and I see this metal tab slide between the tone 2 contact. Again I find no measured continuity between the tone 2 solder point and the on/off solder points in this extreme right position. Is this normal for there to be no continuity across the tone contacts and the on/off points in the second and last position or is this switch not working right? What would be the proper terminology for my switch if I were to order a new one? The picture you forwarded me Edd doesnt really resemble what I have also when this radio was turned on at first the dial tuning light came on and the rectifier tube started to glow but there was no sound at all in any of the switch positions. My huntch is that power is not being supplied to the 2 tone controls and the switch is bad but Im not certain. Thanks again for your input. :Sir Richard. . . . .
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:I certainly don't have one of those chassis to eyeball the switch proper.
:
:
:But in looking at the available photos on the internet, close up chassis pictures seem to show that control as being built, such as to resemble a common larger diameter volume control housing with a common switch mounted onto its end.
:With it not being open wafer construction, such that you can see each of the individuial stationary contacts and the rotor.
:
:
:However, in consulting the schematic, one would see the power switch function being a common SPST switch . . . . . and the long broken line angling up to the tone control switch is showing it as being mechanically ganged to the rotary tone control switch.
:
:
:Would you be my eyes and confirm that your units actual power switch is a unit somewhat similar to the supplied photo at:
:
:
: http://www.ebay.com/itm/Centralab-KR8-FASTATCH-SPST-Rear-Switch-Element-/190509902843
:
:
:There are additional photos of AC switch variants at the bottom of the page.
:
:
:Somehow I want to think that your switch is such that the extreme left rotation of the tone control shaft flips that solitary power switch off, or if you turn the tone control rotary shaft to the first position, the separate power switch is flicked on and stays on for ALL of the further cw positions of the tone shaft.
:
:
:Come back to the 2nd position of the tone control and then the additional movement into position one . . . or tone control function off . . . will then also flick that separate power switch off.
:BTW . . . are we having an intermittent or non functioning power switch problem, as I would expect no problems being had from the separate tone control function switch .
:
:
:I suspicion your switch to be like one Johhny had problems with recently, I would give you that thread, but can't remember it nor locate it with out the sites SEARCH function, but it was with in the last 4 months . . . or so.
:
:
:The perceived "work around" use of a dual section 2 pole 4 position rotary switch, could present a picked up AC hummmmmm problem if the AC wiring gets too close to the section used for the tone control function
:
:
:Also, for the power switching function , it really wants to be a shorting type, make before break action, for the 3 wired together stationary contacts, otherwise AC power will be intermittently disrupted when switching between tone positions.(Unless you are a Speeeedy Gonzales, each time you switch. )
:
:
:As for the tone control wafers section, it would be using a non shorting switching action in its wafer.
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: 73's de Edd
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: The hardest thing in life to learn is exactly which bridge to cross . . . . . and which to burn..
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::Thanks for your help Lewis.I will order this type of switch tonight.
::
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4/24/2012 12:39:29 PMWarren

The AC part of your switch is independent of the tone switching. There is no AC being switched in the tone control section. The switch is duel purpose, an on off switch that stays on as you select tone control capacitors.

4/24/2012 11:05:07 PMEdd

Sir Richard . . . . .

In reiterating . . . .with relevant statement by statement being followed up on:

There are four solder points where 4 wires were connected to each point.

That is being your tone control portion of that individual switch.

The bottom part of the switch is encased in hard plastic and has 2 solder points. I believe this is what turns the radio on.

Correct, that is THE actual " add on " separate main AC power switch for the unit.
It is a SPST unit that just switches the AC power on and off.

The top part of the switch is open wafer and has the other 2 solder points/contacts for the 2 tone controls.
The extreme left position is the radio off position which shows no continuity across the solder points that turn the radio on which seems correct.

That is correct, as the AC power switch has been flicked off with (a CLICKING noise) as the tone control is JUST moved from position #2 into its position #1 (being labelled as tone off on the schema).

As I turn the switch 1 click to the right I measure continuity across the two solder points that house the on /off switch.

That is operating and testing correctly, as theAC power switch has just been clicked ON and it will REMAIN ON on for the other CW tone positions made to the right and only until the tone shaft is rotatred CCW and back to that positioning just before the 1st tone position, will the switch click again to turn OFF the power.

and in the open wafer section I see this little metal tab slide between the first tone contact.

That is the switches movable rotary tab and will rotate on between each of the individual fixed STATOR tabs of the switch.

At this point should there be continuity across the on/off solder points as well as the first first tone solder point/contact?

I only see continuity with the on/off solder points but no continuity between the on/off solder points and tone 1 position even though the little metal tab has slid between the tone 1 contact.

When I turn the switch 1 more click to the right continuity remains on the solder points that turn the radio on and I see the metal tab slide out of the tone 1 contact and rest between the tone 1 and tone 2 contacts.

The final postion/extreme right of the switch continues to show continuity across the on/off switch and I see this metal tab slide between the tone 2 contact.

Again I find no measured continuity between the tone 2 solder point and the on/off solder points in this extreme right position.

Is this normal for there to be no continuity across the tone contacts and the on/off points in the second and last position or is this switch not working right?

What would be the proper terminology for my switch if I were to order a new one?

From what I was able to interpret of just the tone control aspects description given above , seems like that section is working OK with no problems and MAINLY your tone control circuitry is currently of no concern to us, on an inoperative / dead radio aspect.

It would not cut out the audio, but merely effect the way the radio tone sounds.

The one exception could be a shorted tone capacitor connected to one of the stator positions if going to ground. An ohmming out will reveal such a situation . . . . with a decimal 000000237 % probability of a shorted cap.

Edd, the picture you forwarded me doesnt really resemble what I have

I was just suspecting that separate power switch to somewhat resemble that found photo.You get the idea now of the separate power switch portion.

Now if the separate and individual POWER SWITCH clicks on and off and checks as having NO continuity in the tone control max ccw position and continuity in all of the other tone control positions, all is well with the power switching aspect of the unit.

also when this radio was turned on at first the dial tuning light came on and the rectifier tube started to glow but there was no sound at all in any of the switch positions.

If you can still get the pilot light to go on and off (a quick evaluation . . as compared to waiting to see a tube warm up )
every time, get on with checking the B+ output from the rectifier tube and also B+ presence on the plates and screen of the audio output tube.

A quick / no tech equipment needed check out of the AF output tube, B+ presence and output transformer and speaker operationality can be ascertained by the taking of a test clip lead and grounding one end and clipping a 1k resistor in the free clip lead end and then drag that free resistor lead across the plate pin connector of the socket of the AF output tube . . . . FAST, just likeyou were striking a match. .

A scratching/ popping noise will be your reward if all is quasi / O.K. in those mentioned areas.

If that works, move on down to the plate of the audio tube just before the AF output tube and scratch its tube sockets plate pin connector and expect an even louder result.

STANDING BY . . . . . from afar . . . .

73's de Edd

I just can't understand how I got over the hill ! . . . . . without ever being on top .

4/27/2012 10:58:33 PMrichard

Wow, Edd you really know your stuff and have given this newbie alot to chew on. Thanks for your help. :
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:Sir Richard . . . . .
:
:
:
:
:In reiterating . . . .with relevant statement by statement being followed up on:
:
:
:
:There are four solder points where 4 wires were connected to each point.
:
:
:
:
:That is being your tone control portion of that individual switch.
:
:
:
:
:The bottom part of the switch is encased in hard plastic and has 2 solder points. I believe this is what turns the radio on.
:
:
:
:
:Correct, that is THE actual " add on " separate main AC power switch for the unit.
:It is a SPST unit that just switches the AC power on and off.
:
:
:
:The top part of the switch is open wafer and has the other 2 solder points/contacts for the 2 tone controls.
:The extreme left position is the radio off position which shows no continuity across the solder points that turn the radio on which seems correct.
:
:
:
:
:That is correct, as the AC power switch has been flicked off with (a CLICKING noise) as the tone control is JUST moved from position #2 into its position #1 (being labelled as tone off on the schema).
:
:
:
:
: As I turn the switch 1 click to the right I measure continuity across the two solder points that house the on /off switch.
:
:
:
:
:
:That is operating and testing correctly, as theAC power switch has just been clicked ON and it will REMAIN ON on for the other CW tone positions made to the right and only until the tone shaft is rotatred CCW and back to that positioning just before the 1st tone position, will the switch click again to turn OFF the power.
:
:
:
: and in the open wafer section I see this little metal tab slide between the first tone contact.
:
:
:
:
:That is the switches movable rotary tab and will rotate on between each of the individual fixed STATOR tabs of the switch.
:
:
:
:
: At this point should there be continuity across the on/off solder points as well as the first first tone solder point/contact?
:
:I only see continuity with the on/off solder points but no continuity between the on/off solder points and tone 1 position even though the little metal tab has slid between the tone 1 contact.
:
:When I turn the switch 1 more click to the right continuity remains on the solder points that turn the radio on and I see the metal tab slide out of the tone 1 contact and rest between the tone 1 and tone 2 contacts.
:
: The final postion/extreme right of the switch continues to show continuity across the on/off switch and I see this metal tab slide between the tone 2 contact.
:
:Again I find no measured continuity between the tone 2 solder point and the on/off solder points in this extreme right position.
:
: Is this normal for there to be no continuity across the tone contacts and the on/off points in the second and last position or is this switch not working right?
:
:What would be the proper terminology for my switch if I were to order a new one?
:
:
:
:
:From what I was able to interpret of just the tone control aspects description given above , seems like that section is working OK with no problems and MAINLY your tone control circuitry is currently of no concern to us, on an inoperative / dead radio aspect.
:
:It would not cut out the audio, but merely effect the way the radio tone sounds.
:
:The one exception could be a shorted tone capacitor connected to one of the stator positions if going to ground. An ohmming out will reveal such a situation . . . . with a decimal 000000237 % probability of a shorted cap.
:
:
:
:
:Edd, the picture you forwarded me doesnt really resemble what I have
:
:
:
:
:I was just suspecting that separate power switch to somewhat resemble that found photo.You get the idea now of the separate power switch portion.
:
:
:Now if the separate and individual POWER SWITCH clicks on and off and checks as having NO continuity in the tone control max ccw position and continuity in all of the other tone control positions, all is well with the power switching aspect of the unit.
:
:
:
:
:
:
:also when this radio was turned on at first the dial tuning light came on and the rectifier tube started to glow but there was no sound at all in any of the switch positions.
:
:
:
:
:If you can still get the pilot light to go on and off (a quick evaluation . . as compared to waiting to see a tube warm up )
:every time, get on with checking the B+ output from the rectifier tube and also B+ presence on the plates and screen of the audio output tube.
:
:
:A quick / no tech equipment needed check out of the AF output tube, B+ presence and output transformer and speaker operationality can be ascertained by the taking of a test clip lead and grounding one end and clipping a 1k resistor in the free clip lead end and then drag that free resistor lead across the plate pin connector of the socket of the AF output tube . . . . FAST, just likeyou were striking a match. .
:
:
: A scratching/ popping noise will be your reward if all is quasi / O.K. in those mentioned areas.
:
:
:If that works, move on down to the plate of the audio tube just before the AF output tube and scratch its tube sockets plate pin connector and expect an even louder result.
:
:
:STANDING BY . . . . . from afar . . . .
:
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:73's de Edd
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: I just can't understand how I got over the hill ! . . . . . without ever being on top .
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