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40-115 No signal
dfields69
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#1

03-02-2015, 12:08 AM
Does anyone here have experience on the little 6 tube 40-115 transitone? I have recapped, checked resistors and replaced bad ones, tubes are strong. The set comes on and you can hear a faint hum from the speaker but no stations. I've had more of a sruggle with this lil' AC/DC than I had with a model 296! Any common problems anyone has encountered with these sets? The 40-115. Thanks for any help anyone can offer!
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Radioroslyn
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#2

03-02-2015, 06:49 PM
So hows the rubber wiring???? Check for HV on the plates and screen grids on all tubes except the rectifier. In your set 70-100vdc. The rectifier should have about 100vdc on the cathode.All control grids should have a small negative dc voltage on them in relation to the cathode. The cathodes of all except for the rectifier should have very little to no voltage on them.
Terry
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klondike98
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#3

03-02-2015, 08:30 PM
I added a link to the schematic in your original post so folks can better help you troubleshoot your problem.
Cheers,
Bob
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dfields69
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#4

03-02-2015, 09:34 PM
(03-02-2015, 06:49 PM)Radioroslyn Wrote:  So hows the rubber wiring???? Check for HV on the plates and screen grids on all tubes except the rectifier. In your set 70-100vdc. The rectifier should have about 100vdc on the cathode.All control grids should have a small negative dc voltage on them in relation to the cathode. The cathodes of all except for the rectifier should have very little to no voltage on them.
Terry

The bad wiring has been shrink tubed. The wires coming off the I.F. cans are still soft, pliable. Haven't checked the plate/grid volts as I have no line isolation transformer and these ac/dc sets get me a little nervous when out of the cabinet and turnd on....but I can angle it upside down well enough to get at them all. I'll try that and post when done. Radioroslyn you have, again, been very helpful! 
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dfields69
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#5

03-02-2015, 09:36 PM
(03-02-2015, 08:30 PM)klondike98 Wrote:  I added a link to the schematic in your original post so folks can better help you troubleshoot your problem.

Thank you SO much! What a great site! You are all very kind and helpful. I am grateful.... 
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Radioroslyn
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#6

03-02-2015, 09:59 PM
With out a isolation transformer you can measure the ac voltage from the chassis to earth ground. Plugged in one way you will read 120ac and the other you will see a small ac voltage. If you have it plugged in with small ac voltage at the chassis you will be OK to connect your test equipment to it. ALWAYS PLUG IT IN IN THE SAME DIRECTION!!! If you want to double check measure the ac voltage between your chassis and your test equipment. Just make sure that you DO NOT have 120vac between the chassis and anything you connect to it.
Flame suit on
Terry
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simplex1040
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#7

03-05-2015, 03:03 PM
Do you have audio? placing a screwdriver tip on middle of volume control should give you a growl in the speaker.
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dfields69
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#8

03-07-2015, 07:51 AM
Thank you i will try it today!
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dfields69
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#9

03-08-2015, 01:45 PM
No sound when screwdriver was placed on center tap of volume control. That was the key to the problem! Got a friend with a signal tracer to help me and we got it playing! Great sound! The RF amplifier tube in this set appears to help with reception as well. Thanks to everyone for their input and help! I was referred to this site by a fellow hobbyist, and have had nothing but good experiences here. I've learned a lot from reading other posts on here. Very positive experience every time....hopefully I can star contributing soon instead of just asking for help.....
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klondike98
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#10

03-08-2015, 01:59 PM
Icon_thumbup Icon_thumbup Icon_thumbup
Cheers,
Bob
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simplex1040
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#11

03-09-2015, 01:02 PM
So what was the final issue?
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