Airline 94GSE-3018A

[ohohyodafarted]

After more than 6 years away from restoring antique TV sets, due to personal issues, I am BACK IN THE SADDLE AGAIN!

My poor condition Ariline 94GSE-3018A has been sitting on the shelf waiting for about 15 years. Here is a photo of the one at ETF
http://www.earlytelevision.org/airline_94gse.html

Stored in a wet basement the cabinet was falling appart with much of the plywood badly de-laminated. I have the cabinet fully restored and is in very nice condition now.

The unit consists of 3 chassis. Crt chassis with High Voltage and sweep ckts, Main chassis with power supply, tuner and RF and video ckts, and the 3rd chassis which has an AM/FM radio tuner.

The main chassis with the power supply, tuning and video circuits evidently had a fire underneath at one point. A very bad amateur job of repair was done. (I hate working on other people's botched sloppy work) and after fixing all the bad work and re-capping the entirety of all 3 chassies, I have the TV set working fairly well with a somewhat usable 7JP4. It produces a nice picture in a dimly lit room.

NOW FOR THE MAIN PROBLEM, with hopes that someone a lot more knowledgable than I, might be able to help me figure this out.

The AM and FM radio section is totally dead. Not even a hint of receiving anything. I have check and rechecked for any circuitry errors and have found NOTHING. I spoke to John Folsom, and he suggested that I might be dealing with silver mica disease. There are 3 IF transformers in the set, and indeed, the schematic shows that the 3 if transformers have an internal capacitor paralleled with each coil segment. Unfortunately, there are no values for the caps in the transformers. The IF transformers look to be rather specialized. They appear to have an FM and AM set of coils in each transformer.

I took the aluminum can cover off of one of the transformers. The questionable caps appear to be sandwiched between 2 layers of phenolic material that forms the base of the transformer to which the terminal lugs are attached. The 2 layers of phenolic are riveted together. Delicate surgery could be performed to remove the silver mica caps. But without knowing what the values for replacements should be, what does one do?

Would there be a way of pumping test signals through to find out where or if the if transformers have faulty caps?

My test equipment is fairly limited to using meters and a scope. Signal generators and alignment is pretty much out of my abilities.

I don't even know where to begin. I am hoping that I can get some guidance on how to proceed. Or perhaps someone with more advanced abilities than mine, might be willing to step in and give me a hand to trouble shoot this issue.

This link will take you tot he schematic at the ETF site
http://www.earlytelevision.org/pdf/a...sams_93q-2.pdf
The AM/FM chassis schematic is on page 4.

Thanks in advance for your help, and I hope to see you at the ETF convention this year.

Bob Galanter

[Yamamaya42]

Originally Posted by ohohyodafarted

After more than 6 years away from restoring antique TV sets, due to personal issues, I am BACK IN THE SADDLE AGAIN!

My poor condition Ariline 94GSE-3018A has been sitting on the shelf waiting for about 15 years. Here is a photo of the one at ETF
http://www.earlytelevision.org/airline_94gse.html

Stored in a wet basement the cabinet was falling appart with much of the plywood badly de-laminated. I have the cabinet fully restored and is in very nice condition now.

The unit consists of 3 chassis. Crt chassis with High Voltage and sweep ckts, Main chassis with power supply, tuner and RF and video ckts, and the 3rd chassis which has an AM/FM radio tuner.

The main chassis with the power supply, tuning and video circuits evidently had a fire underneath at one point. A very bad amateur job of repair was done. (I hate working on other people's botched sloppy work) and after fixing all the bad work and re-capping the entirety of all 3 chassies, I have the TV set working fairly well with a somewhat usable 7JP4. It produces a nice picture in a dimly lit room.

NOW FOR THE MAIN PROBLEM, with hopes that someone a lot more knowledgable than I, might be able to help me figure this out.

The AM and FM radio section is totally dead. Not even a hint of receiving anything. I have check and rechecked for any circuitry errors and have found NOTHING. I spoke to John Folsom, and he suggested that I might be dealing with silver mica disease. There are 3 IF transformers in the set, and indeed, the schematic shows that the 3 if transformers have an internal capacitor paralleled with each coil segment. Unfortunately, there are no values for the caps in the transformers. The IF transformers look to be rather specialized. They appear to have an FM and AM set of coils in each transformer.

I took the aluminum can cover off of one of the transformers. The questionable caps appear to be sandwiched between 2 layers of phenolic material that forms the base of the transformer to which the terminal lugs are attached. The 2 layers of phenolic are riveted together. Delicate surgery could be performed to remove the silver mica caps. But without knowing what the values for replacements should be, what does one do?

Would there be a way of pumping test signals through to find out where or if the if transformers have faulty caps?

My test equipment is fairly limited to using meters and a scope. Signal generators and alignment is pretty much out of my abilities.

I don't even know where to begin. I am hoping that I can get some guidance on how to proceed. Or perhaps someone with more advanced abilities than mine, might be willing to step in and give me a hand to trouble shoot this issue.

This link will take you tot he schematic at the ETF site
http://www.earlytelevision.org/pdf/a...sams_93q-2.pdf
The AM/FM chassis schematic is on page 4.

Thanks in advance for your help, and I hope to see you at the ETF convention this year.

Bob Galanter

Now you had to go and get that song stuck in my head!
:P

https://www.youtube.com/watch?v=lX8GG3dnsp8

[jhalphen]

Hi to all,
Hi Bob, long time no see.

Airline AM/FM chassis, first things first:
- filaments light?
Wiring loom between PWR supply & radio chassis, do you have the various voltages present (B+), Ground solid & OK?

There are many wafer switches, all susceptible to oxydation/bad contacts.
Have you used contact cleaner (or DeoXit) & vigorously switched back & forth many times to exercise contacts.

Oscillator test: AM band, AM transistor radio next to the Airline. can you hear an oscillator "swish" on the transistor radio when you tune the Airline 455Kc (value of the IF) below the transistor radio's frequency?

Same test, FM, difference between the 2 radios should be 10.7 MHz (FM IF).

Do you have wiring continuity (GND & Signal) from the AM detector out, FM detector out to the Audio Amp input on another of the 3 chassis?

Mica Cap disease: usual symptoms are radio works or weak reception then suddenly you hear very loud "lightning crashes" in the audio. It's totally random.
Of course in severe cases if all 3 IF's have the disease, nothing works.

Course of action: this is mainly a TV forum, here we've got AM/FM radio problems.

I would post a request on ARF in this section. Also include a photo of the AM/FM schematic.

https://antiqueradios.com/forums/vie...2cb3517a24069e

Reading about silver Mica disease, an example, there's tons of info on ARF.
IF it is SMD, Guys will advise about replacement Mica cap values for AM and FM.
https://antiqueradios.com/forums/vie...t=Mica+disease

AM IF can with SMD disease, repair by photos:
https://antiqueradios.com/forums/vie...90994&start=21

Best Regards
jhalphen
Paris/France
PS : Please send me a PM, i don't have your current Mail address.

[Electronic M]

I don't have experience with that model (was asleep at the switch on an auction with one after I won my Westinghouse 15" color a few years ago), but Shango has a fairly solid methodology for repairing SMD. 1.) don't adjust tuned coils till step 5. 2.) disassemble the original caps scrape away shorts and measure with one of those $15 Chinese RLC testers. 3.) install trimmer caps and align those trimmers and check their value to verify values. 4.) install fixed Caps of the closest standard valve to what previous measurements indicate (verify values with meter before install). 5.) align the radio according to the service manual.