Fisher 400 owners PLEASE READ....IMPORTANT!!!!

Larry,
Great work as usual...Thank you for your research into this confusing mess. Those manual guys at Fisher must have been smoking some pretty good weed, eh? I'll get you the info from my 400's ASAP.

John

 

Here's all of the codes from my 400's: Dammit, All of the numbers got scrunched after posting. Anyway, you guys'll get it...

SERIAL RF TUBES OPT SUFFIX EIA CODE

58753W 6 AX 352552
60669W 6 AX 352605
67246X 6 AX 352547
81106AM 6 AX 3946709

I think I have a VERY LATE run of the 400 if you look at the 81106AM Serial#...Note that the "AM"(see pic below)is stamped with what looks like ink rather than a punch. This is the only receiver I have that has this ink stamping. I hope the OPT numbers help you, Larry.

John

 

Dave G, thank you SO MUCH for posting the procedure for testing the primary impedance of our OPT's! Being somewhat electronically challenged, I didn't know how to do this, and I'm very happy to learn something new to slide under my belt for future reference...hmmph, electronic stuff is about the ONLY thing that slides under my belt these days!! Boo Hoo....

John

 

Bruce, I know exactly what you mean, as I had to make a few moves to unhook and slide out one of my 400's in order to get the requested OPT numbers and unit serial #. Mine isn't in a cabinet, so that wasn't an issue.

John

 

John; The transformers with the 6 digit 352xxx codes were built by "Magnetic Windings Co. Eastons, Pa.
The 394xxxx was built by Foster Transformer Co. Cinncinnati Ohio.

58753W------->352552 52nd week of 1965( Last week of Dec.)
60669W------->352605 5th week of 1966 (1st week of FEB)
67246X--------->352547 47th week of1965 (3rd week Nov)
81106AM------->3946709 9th week of 1967 (1st week of March)

These are the Transformer build dates. Add 2-3 months for logistics, manufacture of the 400's, pkg, ship, and purchase. So you could conceivably say that these were sold between

58753W-----> March to April 1966
60669W-----> April to May 1966
67246X------> Feb to Mar 1966
81106AM----->May to June 1967

Looks like FISHER didn't rotate stock either (1st in 1st out). The 67000 series transformers were built 3 weeks earlier than the 58000 series unit 8 weeks before the 60000 series unit. They also could have had multiple lines with different 1000 unit serials running at the same time which would account for this.

.

 

Larry, John's 81106AM has the AX opt's,but with the same 3946709 EIA code as mine; what do you make of that?

 

Art; It's very possible that FISHER had multiple lines running the same unit, in the same plant with each making a 1000 unit batch. 4-5 lines running at the same time would make sense. Also both your's and John's have the AM stamp at the end of the serial. No idea how significant (or insignificant) that is, but it is interesting.

 

Thank you, Larry for those numbers and dates for my OPT's. I'm going to save that info because it's good to know for my own personal reference. Maybe the "AM" means the morning shift, and you know how those day shifters are, right?....all hung over and seeing double. Can you imagine having to concentrate on the inside of a Fisher chassis still half in the bag? haha

John

 

Just checked mine and I have one the same as Arts':

SN: 77428 AM
OT: T1020-116-1 (second OT is T1020-116-2)
3946705
IF: 4 tube
RF: 2 tube

 

Here's another from the 'morning shift' - good one John.

74131AM
T1020-116-1AX
352647
4 IF tubes

 

Mine is s/n 59018, AX outputs, tube layout like this:
http://audiokarma.org/forums/index....n-advice-requested.570663/page-3#post-7498166
Is this 4 IF tubes?
John

 

nerdorama. You have the 4 tube IF STRIP
Thanks John.

 

Now that the threads are back where they are meant to be (thanks FISHERDUDE), I'll start collating the info, with all the differences. Might take a week or so in between honey do's and stuff.

Just wish we had more owners with units in the 30000 to 50000 range.

Additional information is welcome at any time.

Larry

 

I posted in the tube audio section. I need to update my serial number. It is 37998T, forgot the T earlier.

 

RICKY W's original post from the Tube Forum Thread:

This is an Anomaly; An early version with the 3-IF tube strip (5tubes total for tuner), an EARLY SERIAL # (37798 or37998T) with the AX transformers. FISHER must have been hot to trot on the transformers if these are originals.

Ricky; How long have you had the 400? Do you know it's prior history with regards to repairs? Would you take some pictures of the inside of the unit around the output transformers, and output tube sockets, please. If someone replaced these at one time this would be the most logical area to look at for lousy solder joints, dry joints, non factory joints.
There's a couple of possibilities here.
1.) it came from the factory this way (with the AX Transformers and circuit changes to accomodate the TFRMRs)
2.) It originally came with non AX transformers and they were replaced by a shop in the past and the circuits were changed to reflect the new transformers (or not).
3.) It originally had the non AX transformers and someone else replaced them, same as #2.

 

Oh boy an anomaly. A 30000 series, with the 3 IF tube tuner, and AX Transformers!!
9264388 breaks down to TODD Electric Co. Yonkers N.Y. date 38th week of 64. Middle Sept.

Here's Ricky's original post from the 400 thread in the tube forum.

Couple of questions for you RICKY W.
How long have you had the 400?
Do you know it's History (Owner/Repair)
Has it been rehabbed or "restored".
Can you take a couple of pictures of the unit (inside and out.) concentrate on the output section with the output tube sockets and the trfrmr wiring showing?

Something in me is wavering on this being factory original. It's a whole 10000 units before the 48001 manual which is used as the cutoff between early and late. Could be one of 2 or 3 possibilities;
1.) This is a FACTORY UNIT (Virgin inside) as built. Which could possibly throw out the baby with the bath.
2.) The Transformers are replacements either from a shop, or someone replaced them in the past. Whether they changed the NFB circuit to accomodate the new transformers is anyone's guess.

Larry

 

Larry,I'm starting to regret my earlier ''can of worms'' comment

 

It was my dads. Probably bought 1964-5 in San Diego California, mom wasn't certain on the year. She doesn't remember any major repairs. I have a receipt from 1971 for rectifier, one 6hs6 tube, a switch (probably power switch), a dial lamp and a fuse, clean controls. My grandpa hotwired a failed power switch later in the 70's. I had it cleaned and aligned about a year ago. I recall the shop saying they added some caps because some were weak. Most tubes are original (say fisher on them ). I ran it for a few hours last year. Ran good except fm would drop out suddenly. Havent investigated that one yet. Thanks Rick. Some pics too.