Yup, that's the meanie awright, (#4) :thmbsp:
Fisher 800-c project
- Thread starter apple_scruff
- Start date
Thanks!
I guess I will sit back and wait for the parts kits to get here and take inventory and order any remaining parts that I need then.
I guess I will sit back and wait for the parts kits to get here and take inventory and order any remaining parts that I need then.
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yet another dumb question... Is the C98 200uf/250vdc cap available in the can form? Or is it best to hollow it out and stuff a replacement in the cardboard can?
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C-98 is a single cap. "Best" is relative. You can pay for a can already built, or buy a cap for a couple of bucks, and stuff it yourself. Depends on your time, patience, and skill set. For C-98, it's pretty straightforward.
You can also undermount that cap and just disconnect the original and keep it for looks.
I opted to stuff; lot's of threads on the subject on AK
You can also undermount that cap and just disconnect the original and keep it for looks.
I opted to stuff; lot's of threads on the subject on AK
BTW: The cardboard is just a cover to keep you from killing yourself. 
Underneath it is a metal can.
Underneath it is a metal can.
Apple Scruff; If you ordered the complete set from Tom @ Hayseed you'll get all 3 caps. One will be insulated with a cardboard cover like the original. The other two will be metal can's. All will have identification stickers on them.
AND you'll get a NEW Phenolic Wafer to mount the cap on. Either use the old one f you can get the cap off it without damaging it, or drill out the rivets, and get some 3/8" 4-40 cap screws and nuts from the hardware store. Once you tighten them down lock them down with either locktite or clear nail polish.
Larry
AND you'll get a NEW Phenolic Wafer to mount the cap on. Either use the old one f you can get the cap off it without damaging it, or drill out the rivets, and get some 3/8" 4-40 cap screws and nuts from the hardware store. Once you tighten them down lock them down with either locktite or clear nail polish.
Larry
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Well crap I just wasted $3.63 on a cap from Mouser! lol... I did order the complete kit from Hayseed... I thought it was just the 2 multi caps!
I ordered some other parts that I thought I may need for this project today from Mouser. I ordered the x/y cap and the misc parts for the IBAM.
I will officially start on this 800-c by adding the screen grid and cathode resistors on Monday. Then wait for the other parts to arrive!
I ordered some other parts that I thought I may need for this project today from Mouser. I ordered the x/y cap and the misc parts for the IBAM.
I will officially start on this 800-c by adding the screen grid and cathode resistors on Monday. Then wait for the other parts to arrive!
Just keep it for a spare! I've done that and later on found a need for it in another piece of gear.
Out of curiousity what is the Serial # on your 800-C.
Out of curiousity what is the Serial # on your 800-C.
491xx I can't remember the last two digits as it is at work.
Thanks. I'm working a theory that there were TWO DIFFERENT VERSIONS in 1963. The standard version and a strictly console only version. There are differences in the NFB and transformers and possibly one or two areas I can't remember right now. Possibly to handle the tonal differences from a console cabinet and the turntable being right on top of the speakers. But that version was only in the 1963 EXECUTIVE console. In 64 the console used the Stand-alone version. It's identical to the stand-alone version in '64. then they went to a Hybrid amp/tuner/preamp(97A-97T) Receiver in '65 for the Executive. Then a custom designed for Console only Solid State Receiver (69-T) in '66, then an adapted standalone SS Receiver in '67 (31-R). The 550-T was the Executive model 973 receiver for '68. The model #'s really screw me up at times. FUN FUN FUN.
Larry
Larry
Larry
Larry
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Hmmmmm....wunder if what you're investigating has something to do with a missing cap in one of my units:
http://audiokarma.org/forums/showthread.php?t=483601
http://audiokarma.org/forums/showthread.php?t=483601
NotDigital; What I'm looking at is the differences between the 10001-19999 series(which was exclusive to the 1963 EXECUTIVE CONSOLE) and the 20001-and up series. There are some fundamental differences namely transformers are slightly smaller with a different part number for 1. Also the NFB circuit is different, possibly to account for (A) the Transformers, and (B) the tonal differences between a console cabinet and standalone speakers and the phono. Mainly wiring and small part differences in those two area.
What I'm really interested in is if ANY of the 10001-19999 series made it out of the factory as stand alones. Based on prior history in numbering the consoles got the 800-C 1st series (10001-19999) in 1963. Standalones started at 20001. In 1964 the EXECUTIVE reverted to the standalone version and had the same schematic as the standalones. the 20001-29999 series, 30001-39999, and 30001-49999 and the Executive 950 and 960 manuals are what i have. The 20001, 30001, and 950 manuals have the vertical Black bar on the right side of the Front Page. The 40001, and 960 manual have the New style Twotone front page. It looks like '64 was the 1st year for the TWO-TONE front page. So we have another possible clue for dating.
Anyway back to the Executive 950 vs. the 20001 schematic. The above were the two major glaring changes found (by BugleGirl and I) while sitting a 10000 series next to the newly rehabbed (Alaska unit) next to it. She noted the Transformers were slightly different on the Executive's chassis. I was taking it home for rehab anyyway so I started to dig into it. The transformers are different, but whether it;s just a manufacturer shift or something more electrically substantial I don't know. The NFB circuit Dave pointed out in a thread about a month ago. So I'm probably going to go thru it with a fine tooth comb (the differences are really subtle and you have to follow the schematic hand over hand to find them.).
But it doesn't have to do with the Stereo beacon circuit.
Larry
What I'm really interested in is if ANY of the 10001-19999 series made it out of the factory as stand alones. Based on prior history in numbering the consoles got the 800-C 1st series (10001-19999) in 1963. Standalones started at 20001. In 1964 the EXECUTIVE reverted to the standalone version and had the same schematic as the standalones. the 20001-29999 series, 30001-39999, and 30001-49999 and the Executive 950 and 960 manuals are what i have. The 20001, 30001, and 950 manuals have the vertical Black bar on the right side of the Front Page. The 40001, and 960 manual have the New style Twotone front page. It looks like '64 was the 1st year for the TWO-TONE front page. So we have another possible clue for dating.
Anyway back to the Executive 950 vs. the 20001 schematic. The above were the two major glaring changes found (by BugleGirl and I) while sitting a 10000 series next to the newly rehabbed (Alaska unit) next to it. She noted the Transformers were slightly different on the Executive's chassis. I was taking it home for rehab anyyway so I started to dig into it. The transformers are different, but whether it;s just a manufacturer shift or something more electrically substantial I don't know. The NFB circuit Dave pointed out in a thread about a month ago. So I'm probably going to go thru it with a fine tooth comb (the differences are really subtle and you have to follow the schematic hand over hand to find them.).
But it doesn't have to do with the Stereo beacon circuit.
Larry
Well today I got a surprise and the mailman brought me the metalbone kit. I stayed after work for an hour and got quite a bit of it installed. I got all of the preamp and phase inverter caps in. I need to put in the 2 MPX caps in. I lifted the cathodes from ground and will install the 10 ohm resistors tomorrow. I prepared the screen grid section to add the 100 ohm resistors tomorrow. I will also tackle the bias power supply tomorrow and then I will have to wait for the caps from Hayseed to come in a few weeks or so to do the rest. That will give me time to clean the chassis and restore the wood case along with other minor tasks.
My workbench I did this on is an old desk that was from the Fisher factory of the period!
My workbench I did this on is an old desk that was from the Fisher factory of the period!
Now THAT's a Factory rebuild. LOL!
Well I got done what I wanted today. I also changed the control grid resistors to 220k. I also temporally hooked up the bias without the IBAM. It was the first time in about 10 years I listened to the 800C! It felt good to hear it. I noticed it sounded weak and distorted in one channel so I checked the voltages and found a weak output tube with low emission. I came home and looked for some 7591 output tubes and no joy all I found were 5 new GE 7868's.
I will need to get some new 7591 output tubes for it.
I also cleaned the dial glass and put new foam around it.
I finally told my dad I was restoring the 800c today. My dad gave me the 800c 25 years ago. I was going o surprise him after it was done but I could not wait! My dad also came over to have a look. I have told a couple of you guys but my dad worked at Fisher for ten years. He started in 1964 in Reedsville Pa and started on the line as a technician then he moved to production test supervisor then eventually to the west coast service manager in Sunnyvale Ca. I was born in California during this time. They wanted him to move to LA and he said no so he went to work for Pacific Stereo in the service department. We all seemed to want to move back to Pa so he left Pacific Stereo in 1975 and we moved bak to PA.
He was pretty happy to see me restore it. He then said he will help me check the alignment and check the sensitivity and perform the other tests.
It was amazing to me how after almost 40 years he knew what everything was and rattled off part numbers without looking at the schematics!
I am glad I did not wait to tell him because it will give us something to do together.
I will need to get some new 7591 output tubes for it.
I also cleaned the dial glass and put new foam around it.
I finally told my dad I was restoring the 800c today. My dad gave me the 800c 25 years ago. I was going o surprise him after it was done but I could not wait! My dad also came over to have a look. I have told a couple of you guys but my dad worked at Fisher for ten years. He started in 1964 in Reedsville Pa and started on the line as a technician then he moved to production test supervisor then eventually to the west coast service manager in Sunnyvale Ca. I was born in California during this time. They wanted him to move to LA and he said no so he went to work for Pacific Stereo in the service department. We all seemed to want to move back to Pa so he left Pacific Stereo in 1975 and we moved bak to PA.
He was pretty happy to see me restore it. He then said he will help me check the alignment and check the sensitivity and perform the other tests.
It was amazing to me how after almost 40 years he knew what everything was and rattled off part numbers without looking at the schematics!
I am glad I did not wait to tell him because it will give us something to do together.
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Glad you got your dad involved. He's probably like a kid in a candy store. And it won't rub off. Write down as much as you can.
I volunteer on the sub down in baltimore, since 1998. About 2000 I got Dad involved again (he was a Radarman cross decked to E.T.). One day he found the manual for the SS-2 Radar and I watched him open the book by putting his thumb somewhere in the middle and opening the book. I hear (very loudly) "SON OF A BI***"!!!!! "What's wrong"? "NOTHING! I haven't seen this manual since I was on ROCK in 1956 and you were in diapers, and I opened it to the EXACT page I wanted"! I looked and the manual was opened to the section on "Care and Maintenance of the Magnetron".
It's SCARY sometimes what they come up with. He's our tube gear Guru. If it's on board and has to do with Communications, Navigation or Electronics countermeasures, he owns it! He's gotten stuff running that even the Navy Master Chief's (chip wienies!)said wouldn't work! And he's 80!
Larry
I volunteer on the sub down in baltimore, since 1998. About 2000 I got Dad involved again (he was a Radarman cross decked to E.T.). One day he found the manual for the SS-2 Radar and I watched him open the book by putting his thumb somewhere in the middle and opening the book. I hear (very loudly) "SON OF A BI***"!!!!! "What's wrong"? "NOTHING! I haven't seen this manual since I was on ROCK in 1956 and you were in diapers, and I opened it to the EXACT page I wanted"! I looked and the manual was opened to the section on "Care and Maintenance of the Magnetron".
It's SCARY sometimes what they come up with. He's our tube gear Guru. If it's on board and has to do with Communications, Navigation or Electronics countermeasures, he owns it! He's gotten stuff running that even the Navy Master Chief's (chip wienies!)said wouldn't work! And he's 80!
Larry
I just LUV these stories!!! :yes: :yes:
Thanks guys!
Larry your dad sounds like a great guy and a great guru!
I do have some stories that he has told me over the years. Some are funny some are sad. I will write them down and ask him to review them.
Today I mesed around with the bias and built a psuedo IBAM out of fixed resistors to force more current through the weak tube. It sounds ok but I will have to get new tubes. I am still waiting for the pots so I can build the real IBAM.
I replaced some noisy 12AX7's in the preamp.
I still noticed poor volume linearity when turning the volume control. I injected a signal into the aux ins and started tracing the signal. I found that the volume control was at fault. I removed the volume control and cleaned it with contact cleaner and the used dioxit and put it back in and it tracked linearly.
I then put it temporarily into the case and hooked it up in my office to speakers (yesterday I used headphones so today was the first real listening test). I listened to an old album of a local band. I thought it fitting to listen to the local band through the Fisher that was made here as well. I really sounded good! One question kept coming to my mind... Why did it take me this long to restore it?
I checked B+ ripple and I am glad I have the capacitors on order. It is not terrible but should be done. Once they arrive We will move onto the checking and aligning the tuners. Both the AM and FM work and sound good so it may be fine!
The last thing I did was put a coat of tung-oil on the case.
Any recommendations on the 7591's? From reading it sounds like the EH 7591a's are the ones to get out of the new current tubes. Is this correct?
I have attached a photo of it hooked up today.
If this is boring you all let me know!
Larry your dad sounds like a great guy and a great guru!
I do have some stories that he has told me over the years. Some are funny some are sad. I will write them down and ask him to review them.
Today I mesed around with the bias and built a psuedo IBAM out of fixed resistors to force more current through the weak tube. It sounds ok but I will have to get new tubes. I am still waiting for the pots so I can build the real IBAM.
I replaced some noisy 12AX7's in the preamp.
I still noticed poor volume linearity when turning the volume control. I injected a signal into the aux ins and started tracing the signal. I found that the volume control was at fault. I removed the volume control and cleaned it with contact cleaner and the used dioxit and put it back in and it tracked linearly.
I then put it temporarily into the case and hooked it up in my office to speakers (yesterday I used headphones so today was the first real listening test). I listened to an old album of a local band. I thought it fitting to listen to the local band through the Fisher that was made here as well. I really sounded good! One question kept coming to my mind... Why did it take me this long to restore it?
I checked B+ ripple and I am glad I have the capacitors on order. It is not terrible but should be done. Once they arrive We will move onto the checking and aligning the tuners. Both the AM and FM work and sound good so it may be fine!
The last thing I did was put a coat of tung-oil on the case.
Any recommendations on the 7591's? From reading it sounds like the EH 7591a's are the ones to get out of the new current tubes. Is this correct?
I have attached a photo of it hooked up today.
If this is boring you all let me know!
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Boring??? BORING???? Are you Kidding???? Any guy who's Dad worked at Fisher can bring an ugly girl to the party here and I'm pretty sure everyone would dance with her!
Yeah 7591EH's. Get them from Jim McShane. He tests them on a custom testing rig, and has tube testers that can put them into a coma! His testing is so much more extensive than anything else out there, that what he calls a cull, others will sell as good. His prices are right in line with everyone else. I get my 7591's from him and never more than 48 hours from order to product in hand.
The 1st set I put in my Sansui 1000A (Which puts almost 500V on the plates) and ran them for 2 years @ 38ma. Then a year and a 1/2 in the 800-C @ 34ma and now back in the 1000A, now that I have another set for the 800-C. I check both sets monthly (Takes about 5 minutes per unit). Neither set has varied in bias more than 1ma. I've got a quad of old worn out Westinghouse marked Eico and Curtis Mathes that on a good day put out 29ma max and most days 20 to 26ma. I still use them for 1st tests.
I think part of the longevity is the screen resistor mod, and the grid resistors and coupling cap mod.
The only thing i have against them is the size of the bottle. If you use a case for the 800-C, make sure the tubes are OUT prior to pulling off or putting on the case.
AFAIC the JJ's are KLUDGE!!! Some guys swear by them, but I've seen and heard too many horror stories on them. I'll stick with the EH's. UNLESS Someone wills me a couple quads of NOS Westies!
NO AFFILIATION with McShane. Just a completely satisfied Customer.
Larry
Yeah 7591EH's. Get them from Jim McShane. He tests them on a custom testing rig, and has tube testers that can put them into a coma! His testing is so much more extensive than anything else out there, that what he calls a cull, others will sell as good. His prices are right in line with everyone else. I get my 7591's from him and never more than 48 hours from order to product in hand.
The 1st set I put in my Sansui 1000A (Which puts almost 500V on the plates) and ran them for 2 years @ 38ma. Then a year and a 1/2 in the 800-C @ 34ma and now back in the 1000A, now that I have another set for the 800-C. I check both sets monthly (Takes about 5 minutes per unit). Neither set has varied in bias more than 1ma. I've got a quad of old worn out Westinghouse marked Eico and Curtis Mathes that on a good day put out 29ma max and most days 20 to 26ma. I still use them for 1st tests.
I think part of the longevity is the screen resistor mod, and the grid resistors and coupling cap mod.
The only thing i have against them is the size of the bottle. If you use a case for the 800-C, make sure the tubes are OUT prior to pulling off or putting on the case.
AFAIC the JJ's are KLUDGE!!! Some guys swear by them, but I've seen and heard too many horror stories on them. I'll stick with the EH's. UNLESS Someone wills me a couple quads of NOS Westies!
NO AFFILIATION with McShane. Just a completely satisfied Customer.
Larry