The Fisher 202-R Tuner

[audmod01]

I have a question for anyone who has a Fisher 202-R and Fisher schematic for the same: there is a capacitor, C111, shown from terminal 4 to 2 of Z11 (the AM detector transformer) and I need to know its value. The parts list of the Fisher service manual does not list a C111 and I have not received my 202-R yet to be able to inspect it and determine the value of C111. It is outside the dashed lines around the detector transformer, which indicates it is an external capacitor, not inside the transformer shield. I have been modifying the Fisher service manual schematic page to show the capacitor and resistor values. After I finish I plan to go to Office Depot or Kwik-Kopy and get an 11 X 17 inch print of the schematic so I can glance at it as I work on the tuner. Having the values on the schematic makes servicing it much easier for me.

After I receive the capacitor value I will make the updated schematic available to members. I will send it to the Fisher AudioKarma.org database for posting.

Joe

 

[mrphilco]

If I don't forget I will check tonight. (I have the Sams Photofact for the 202-R and it might list the cap in question in case mine does not have that cap.)

 

[mrphilco]

It's on the Sams Photofact schematic (as C99). The part in question is 1 pF, NP0.

 

[gadget73]

Having the values on the schematic makes servicing it much easier for me.

yeah thats one of the irritating things about how Fisher did their service docs. I'm glad they exist and in pretty high res, but having to print the whole thing and shuffle pages around for parts values is definitely not convenient.

The one I printed for my TA-600 has it on regular size paper that I cut and taped together as needed to fit. I also have component values scribbled in where I had to look them up for some reason.

 

[mrphilco]

Gadget, you can say that again! I went though that same issue with my TA-600. I did not have a Sams Photofact for it - just the original Fisher service manual.

 

[audmod01]

Ron;

Thanks for looking that up for me. Now I can finish adding component values to the schematic.

Joe

 

[audmod01]

Ron and Gadget;

If you would like a copy of the modified schematic with component values, which I just finished, and don't mind sharing your e-mail address, send me a PM and I will send you a copy. I also added some notes to the drawing regarding the AM section functions.

Thanks again for your help Ron!

Joe

 

[mrphilco]

No problem, Joe, glad I could help. Thank you for the offer of the schematic. PM forthcoming.

 

[audmod01]

Ron;

Schematic sent, should show up soon.

A few years ago you helped me with a 12" speaker for my Philco 40-201 restoration. It is still working well, thanks to you and others.

Joe

 

[dcgillespie]

Joe -- Any chance I could get a copy as well? I'd love to have one for my files --

Dave

 

[gadget73]

Hey Ron, did you mention you'd picked up a Fisher MPX unit out of one of the recievers to make into an external decoder? Which model? I picked up another WX recently and made myself a wiring key if you need it. I've got it running "kill you to death" mode on the bench run from the old Heathkit power supply at the moment, but it's doing well with random used tubes and a Bogen FM-50 tuner. Not a clue how decent the tubes in it are, they were just stuff I had laying within grabbing distance. I have the VTVM standing in for the eye tube, and its giving me a solid -5v on a reasonably strong station.

 

[audmod01]

Joe -- Any chance I could get a copy as well? I'd love to have one for my files --

Dave

Dave;

Will do, you should have it soon.

Joe

 

[audmod01]

There is a faceplate for a 202-R on eBay this morning. Unfortunately, it is just as corroded as Ron's and the one on the tuner I have coming to me. I am thinking that I may have success with cleaning and polishing around the lettering using toothpicks and Turtle chrome polish. Then the rest can be handled with Q-tips and chrome polish or perhaps even a folded piece of cloth. Once the cleaning and polishing is done, it could be protected with a thin coat of clear lacquer or have some carnuba wax with no abrasives applied to help prevent further corrosion.

Joe

 

[mrphilco]

Hey Ron, did you mention you'd picked up a Fisher MPX unit out of one of the recievers to make into an external decoder?

Gadget - yes, I did. I can't remember if it is a WX or an MPX-65. I will check and confirm when I get home, and let you know. A wiring diagram would be great, thank you!

 

[mrphilco]

There is a faceplate for a 202-R on eBay this morning. Unfortunately, it is just as corroded as Ron's...

...no...mine isn't corroded that badly...that one is pretty rough...

It has been on there a while, listed and relisted. Crazy as it may seem, I was tempted to buy it and experiment with cleaning it. But I dunno, $30 plus shipping for a very rough panel seems to me to be a lot to waste if it did not turn out well.

 

[dcgillespie]

Gadget -- If your MPX sub-chassis is the WX version, your -5 vdc reading is rather low. The typical voltage produced at the indicator output of a WX sub-chassis is more on the order of -12 to -14 vdc. On the other hand, if it is a MPX-65, the output will be about half that amount.

Dave

 

[audmod01]

Anyone have a scan of the 202-R Owner's Manual?

Joe

 

[mrphilco]

Hey Ron... I picked up another WX recently and made myself a wiring key if you need it.

As it turns out, mine is an MPX-65. But I would still like to see your wiring key. It might give me a few additional ideas. I will send you a PM, er, "conversation" on this subject.

 

[mrphilco]

At the workbench.

My tube order from Jim McShane arrived today, and...I am happy to report that AM has come back to life with a vengeance!

I went ahead and ordered all of the tubes for the AM side even though two of them still tested good. Am I glad I did! AM is now pulling in the signals, nice and strong, just on the ferrite antenna.

Now that it has these new tubes, I think I will repeat the AM alignment this weekend, and then I can button it up and call it finished!

 

[gadget73]

WX version, your -5 vdc reading is rather low.

Its higher on other stations, but those happen to have lousy music so I don't know exactly how high it goes. It only says "WX" on the top so I expect thats what it are. Two 12AT7 and one 12AX7.

Possible its somewhat tuner related, or just old components. This is strictly as-found, all old guts with tubes that I didn't bother to test. Not impossible something is not quite optimal, in fact I'd expect it to be so. I could compare it to the other WX that I have on the same tuner just to see what it does.