Checking the voltages on the 35L6, pin 3 should be 110VDC but reads -2.6. Connected are a green wire leading to the speaker transformer and a capacitor (.04). Replacing the cap did not produce any change. Is the reading telling me I have a bad spaeaker transformer?

There are two schematics 1 is the portable. The other with the 35L6 is the electric current type.
http://www.nostalgiaair.org/resources/061/M0025061.htm
Thanks,
Greg

Providing that you have established having B+ on the lead of the output transformer that is fed from the B+ supply line , then yes , you have an open output transformer primary . Usually , if the wires are colored , the red one gets fed B+ and the blu one goes to the output tube's plate . Since there are no other capacators connecting to your plate which could be dragging down the voltage by being shorted , then having no voltage at that plate means that either the transformer aint getting any , or it aint passing any on to the tube .

Have you checked to see that the B+ side of the output Transformer is getting it's specified B+ ?

This is the correct link for 6D030 http://www.nostalgiaair.org/PagesByMode ... 025112.pdf
With the set un-plugged, you should check the resistance from the red lead to the blue or green lead, should be a few hundred ohms. Red to brown lead wil be less than 50 ohms.
If that is good, What is the voltage on the electrolytics with power on? I hope you replaced them. R11 - 22 ohms probably burned out if the electrolytics are shorted.
Be sure you have a #47 pilot lamp installed to prolong the life of the 35Z5
Don

Thanks for the advice. I will follow through.
Incidently, the original 35L6 showed a short. I needed to replace 5 of the 6 tubes. All caps are done. A new #47 was installed.
And the 22 ohm also needed replacement.

Thank you!

This doesn't bode well regarding your original speculation about the audio output transformer and your voltage readings. It's all making a blown primary seem increasingly likely.

Curtis Eickerman

The schematic posted by Greg shows no 22 Ohm on the parts list.

I do note that that circuit does list the DC resistance of original coils, including the speaker transformer primary. That resistance should be able to be tested "in circuit" as the circuit is from the plate to the screen. (pins 3 & 4 )

Often (and if there is some residual magnetism... electrodynamic) if you strike a battery across the primary of the OP transformer, it will make noise in the speaker if all is well. This one is not looking good.

Marc

There is a low noise in the speaker. Also, if I disconnect the 40MFD neagative I receive a low hum.

Suddenly I am starting to get suspicious of a wiring error and other issues. Both c14 & c15 are 20mfd on the circuit and the set will produce a lower voltage and more ripple if C15 is removed. I find it unusual for a speaker to hum if the primary has failed.

As modern caps rarely have surge volts on them, I would hope that the filters are 450VDC or more. It is not unusual to have a cap get to certain voltage & then let go.

Pay particular attention as to what is on the pins of the 35L6 Pin 6 is not connected and may be missing from the tube base. However, pin 6 on the socket may be used for a tag of convenience and there may be a miswire there?

I would prefer C5 to be a mains rated cap as it is going to chassis, and, as the chassis is not carrying mains, I would consider mains grounding it, utilising a 3 wire cable.

Marc

I thank everyone for their guidance. Interestingly, doing a google search on the radio model I discovered a quite lengthy similar situation from a 2009 ARF forum. There are 4 pages of testing, pictures, and back & forth discussion. At the end, the ARF member is still not able to get the radio working and another ARF member who has the same problem joins the discussion.
So, I will work with some of the advice given at this link:
http://174.122.4.235/~antiquer/forums/viewtopic.php?f=6&t=104744&sid=879f65506d3e892b91f9f8888a3a57b2

I would like to think that this one will not run to that many pages. The Path of B+ to pins 4 & 3 is quite easy and does not require a live set.

Not worried about the heater if it lights up. Pins of interest are 3, 4, 5, and 8. The voltage zero (B-) reference is not specified, or the meter used: Which is not helpful. Possibly the neg end of c15? The OP tube voltages we are looking for are those listed on the bottom of the schematic. Note pin 1 and 6 are shown as not connected to anything.

Being transformerless, watch where you put you fingers.

Marc

After spending about 3 hours of testing between Saturday and Sunday morning I was down to my last testing idea. Checking my speaker inventory I found a similar 4" speaker with a transformer containing three wires.
It took a few different arrangenments and then, finally, sound was heard. I moved the radio to the best reception location and gave another test. It was indeed the speaker's transformer.
This radio is playing loud, clear, and is music to my ears. Whew! I almost put this one away for awhile. I am glad that I didn't give up.
Thank you everyone for your help and guidance.

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