Fisher 500-S Rescue, Prologue: Advice Sought

[mrphilco]

I have acquired something I am looking at as a long term rescue project:

It's pretty clean overall, and the front panel is decent.

Problems:

* No iron! No power transformer. No audio transformers.

* No bottom cover.

* No plastic masks for the magic eye tubes.

* No tube shields.

* No knobs.

* And, of course...no off-on switch/volume control.

I have an FM-50-B junker which will furnish one of the missing magic eye masks and at least one tube shield. And I just bought another parts unit which will furnish an off-on switch/volume control, the other magic eye mask, more tube shields, and some hardware; not to mention yet another MPX-65 for my growing unintended collection of those, and a wide band ratio detector transformer which will go into a recently acquired 100-T Coronet tuner/preamp.

While it may be true that I've been in the vintage radio hobby for 43 years and specializing in Philco for the last 27 years, I'm still a relative noobie when it comes to Fisher. So...I humbly come before you, the wise and seasoned Fisher pros, seeing your advice and input on these questions:

* Is this a feasible project, or am I just crazy?

* What other bottom panel will fit a 500-S chassis?

* What do you think of Edcor, Transcendar, or ??? for replacement audio transformers...or should I hold out for original Fishers from a 500-S or TA-600 junker?

* Can anyone give me the specs of the original power transformer (in case I end up having one made by Heyboer Transformers)?

I look forward to hearing from you folks. This is not something I intend to start on right away, but I am hoping to start on it during the winter of 2018-19 (in other words, next winter, not this one). Many thanks in advance.

 

[larryderouin]

I've seen crazier so I think you're ok here. Chassis looks good and parts aren't totally unobtanium.

Bottom panel maybe a TA-600 or TA-800, although as the 500-S and TA-600 are both 7189 units they should be closer to each other.

I wonder if the output's might be similar. (500S vs. TA-600) I would start looking for FISHER transformers 1st.

If too much then I would check with Transcendar 1st to see if they could build to spec. I don't think Edcor or Hammond will do so.

If you can find a 500-S photofact, it'll have the spec's for the Power Trannie.

 

[gadget73]

If you can get some measurements, I have a spare TA-600 bottom that may fit. Its not particularly nice but you can probably clean it up enough to make it useable. Yours if you need it.

I have a TA-600 power transformer too, not sure if that will fit or not.

 

[mrphilco]

Gadget - thank you, that is very kind of you! I'll take some measurements when I get home from work and get back to you. I think the TA-600 power transformer would physically fit but I don't think the electrical specs are the same - I will check on that tonight as well, as I now have the Sams for the 500-S as well as original Fisher lit for the TA-600.

Larry - thank you also for your thoughts. I hope you are doing OK.

 

[audmod01]

Ron;

What Fisher part numbers does the Sams for the 500-S give for the power transformer and output transformers? We may be able to put together a list of potential Fisher donor models for those.

Joe

 

[mrphilco]

Hey Joe,

I'll check tonight when I get home from work.

 

[mrphilco]

Okay, Joe, here we go:

Audio transformers:
TA-600: T720-116
500-S: T799-116 (7K PP to 4/8/16 ohms per Sams)
TA-800: T806-127 (6.3K PP to 4/8/16 ohms per Sams)
500-B: T860-116-3 or -116-4
800-B: T860-116-3 or -116-4
500-C: T991-116-1 or -116-2
800-C: T991-116-1 or -116-2
400: T1020-116-1 or -116-2

Power transformers:
TA-600: T720-115
500-S: T799-115 (Sams specs: 150V @ 660 mA, 6.3V @ 1.3A, 6.3V @ 5.6A)
TA-800: T806-115 (Sams specs: 150V @ 750 mA, 24V @ 500 mA, 6.3V @ 3.6A, 6.3V @ 2.9A)
500-B: T860-142
800-B: T860-142
500-C: T991-115
800-C: T991-115
400: T1020-124

Gadget, it looks like the TA-600 power transformer won't work without serious modifications to the circuitry.

I threw in all of the audio transformer part numbers for the heck of it. Obviously the TA-800, 500-B/C, and 800-B/C use 7591 tubes instead of 7189s. Since both the TA-600 and 500-S use 7189 tubes and the plate and screen voltages are close (not identical, but close) between the two, am I correct in assuming that TA-600 audio transformers will work in a 500-S? Obviously the plate impedances are the same, so on paper, in my mind anyway, it seems that they would.

Joe, now you know that the 500-B and 800-B use the same power and audio transformers, and likewise the 500-C and 800-C share power and audio transformers. That isn't relevant to this project but consider it a "fun fact".

Gadget, I'll post those 500-S chassis measurements in a little while.

 

[mrphilco]

The bottom of the chassis measures 16 inches (left to right) x 12-3/8" (front to back). Gadget, I'll start a convo with you on this subject.

 

[larryderouin]

Ron; I'm doing OK. Got the cremains y'day and internment is next Wednesday at National Veteran's Cematary in B'more. House is slowly getting cleaned out. all her clothes are gone now. As are the knick knacks (salt & Pepper shakers from everywhere except BumF#&*@, Egypt. She'd have found a set from there given 1/2 a chance)which I doled out to female relatives. The rest went to Goodwill. Piano got stripped and the wood will supply about 2 weeks of fuel for the wood stove. Slowly working my way thru the dining room (6 year old grand daughter got all the china, crystal, and Dee's wedding dress plus the cabinet), swapped the dining and living rooms back to original locations. Living room is now the way we wanted it. 65 Futura under the flat screen, the 58 Contemporary in a corner next to my recliner. The dining room now has room on the walls for the rest of the FISHER consoles in the spare bedroom. I may move the Futura to the dining room and put the 59 610/560 combo under the TV on the wall to match the Contemporary.

I've resigned myself to the fact I'm single again, but the dog is mopeing around waiting for Mommie. It's really pathetic, so I'm throwing balls for her and she's got a rubber horseshoe for 2 years now she hasn't been able to hurt. She's real good at Tug-o-War, For hours on end it seems. So I have to hide it or she's gonna pull my arm out of the shoulder socket.

Larry

 

[gadget73]

Ron, also consider the X-100 transformers. Don't know what they are offhand but its another Fisher 7189 amp. Seems people are occasionally looking for singles of that, maybe you can find someone that put TA-600 transformers on their X-100 and will part with the lonely one. Apparently they aren't identical, but are compatible.

 

[kcline]

I happen to have the Sam,s for the SA-100 another 7189 amp those outputs are 6500 Ohm Ct. part number T782-116-1&2 also has replacement outputs made by Halldorson # 22S68 and Thordarson # 22S68 !!

 

[mrphilco]

Thanks, guys. It appears that I will have no problem sourcing audio transformers for this 500-S when I am ready to start working on it.

 

[mrphilco]

Larry, it sounds like you have found good therapy in staying busy. Take care, we're all pullin' for ya. As old Red would say, "We're all in this together."

 

[mrphilco]

Question for anyone:

How are the EM84 tubes held in place on the 500-S?

It looks like only one or two springs were used per tube, nothing else. There are small holes, one above and one below each eye tube opening where it appears a spring would have been hooked. Nothing else there on my 500-S.

 

[larryderouin]

EM-84 depending on the unit either has a long barrel machine screw tapped into the front panel (only seen this on TA-600 and one console) or more often a spring.

 

[gadget73]

If you're missing the hardware, I have a parts 600. The 600 uses a plate with a spring clip, and a long screw through the front panel that is held in with a nut from the back side. Don't know if the 500S uses that setup or not but I'm pretty certain I've got one. Also yours if you need it. I forgot to grab that bottom plate this morning to pack up anyway.

 

[mrphilco]

Larry and Gadget - Thanks. No, the 500-S is set up differently. I'll take some photos this weekend and post here.

 

[mrphilco]

Here are a couple pictures illustrating how I believe the EM84 tubes are mounted behind the dial in the 500-S:

I have since received confirmation from another AK member who owns two 500-S sets that the EM84s are indeed held in place by a spring on each tube. It makes sense, with only a hole below and a hole above where the tube would mount...holes that appear to be just large enough for the end of a spring to hook into.

 

[mrphilco]

And so it begins...sort of...

Today, not one, but two parts sets arrived. The first is a 1964 model 690-T which was pulled from an Ambassador VI or Futura V console:

This chassis will furnish an off-on-volume control (which tests good!), two large tube shields, and its AM ferrite antenna. I was going to use its plastic shadow mask to fill one of the EM84 holes in the 500-S dial, but the 690-T's shadow mask is black, not brown. No worries, though, as you will see in my next post.

Here are the two large tube shields now in the 500-S.

Curious about how the EM84 mounts in the 690-T chassis?

 

[mrphilco]

The other parts set which arrived today is a sad old FM-50 tuner.

It will furnish its (brown) EM84 shadow mask, a couple knobs, and one more large tube shield. A brown shadow mask from a junk FM-50-B I already had will take care of the other shadow mask.

So, here are things as they currently stand:

Notice how the 500-S now has a volume control? The shaft is a bit long. I'll shorten it later.

The three smaller knobs are all from the FM-50 tuner. Two of them are not correct for this receiver, yes, I know.

The two EM84 tubes were both bad, but I have a few good spares.

I have a TA-600 bottom panel in the works for this receiver, and now need one more tube shield and some knobs. I'm already in discussion with an AK member about the knobs, so that may be taken care of soon. And, of course, I still need the iron but that can wait a while as I don't want to start restoring this unit yet. I want to restore my 100-T Coronet tuner-preamp first, convert an MPX-65 to work like a WX and install it in the 100-T, and put that unit into service. Then I have an FM-100 tuner to finish up.

Incidentally, I'll be using the wide band FM ratio detector from the 690-T in my 100-T Coronet and may, or may not, use its MPX-65 in the Coronet as well. I now have three MPX-65 units on hand, plus a WX from a junk FM-50-B. The MPX-65 in the 690-T is the cleanest looking one of the three I now have.

Later, I will pursue more of the needed parts for the 500-S. But I would say that I'm off to a very good start on it already.

Thanks to everyone for the comments. I would say that this thread has accomplished its goals. I'll start a new one when I actually start restoring the unit, which will not be for awhile.