SAE 8000 Tuner Schematics

Folks,

I was wondering if anybody has a copy (PDF preferably) of the SAE 8000 Tuner schematics. I am trying to repair the LED issue and to replace some components to make it more palatable to modern high-end standards.

Thanks in advance.

Yves
 
Thank you. I had read that thread before and it is very interesting.

However, I really would like the schematics of that tuner as I am trying to rebuild it and improve the components and the overall quality.

Thanks
Yves
 
Schematics Mark VIII/8000

Please!

Does anybody know how to rewire the unit for 220~230 Volts?
Thanks in advance.
 

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  • Schematic SAE 8000 FM Tuner.jpg
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As you can see from the schematic, it is not possible to rewire the unit for 220-240 V European voltages. I just re-did the power supply of my Tuner 8000 and can confirm that the primary of the transformer has only a single winding suitable for 110V AC.

The original transformer is a 110VAC primary and 2 x 10VAC secondary. By replacing that transformer with a small 220VAC primary and 2 x 9VAC secondary you can easily retrofit your Tuner for European countries. It shoudl be a piece of cake to do, and you can even install a small toroid transformer which will work better than the old box from the 70's.

Yves
 
Brian,

If you have the schematic of the Digital readout section for the 8000, could you post it?

I only had the Mark VIII schematic and there are a few differences with the 8000 Tuner. For instance, on the Mark VIII, the main switch cuts the primary of the transformer, whereas on the 8000, it is the secondary which is switched.

I have reworked my 8000 to have a power supply more in line with the Mark VIII as I do not like to leave the transformer on at all times.

Yves
 
This tuner has 5 ganged circuits in the VHF front-end, and 5 ceramic filters in the IF followed by a ratio detector. This suggests to me that it was designed to cope with lots of input signals on nearby channels, and audio quality might have been less important. Or possibly just aiming at specmanship; 5 filters sounds so much better than 3 filters in a glossy ad (and forgetting about phase response). I could be wrong of course. The Foster-Seeley discriminator seems to have been preferred by most high quality units before they all switched over to using a chip-based quadrature detector.

Sprinkling in a few new components won't change the basic design.
 
That is true. However, listening to Radio is not my top priority, and the quality of the sound is more than acceptable.

I am basically restricting the replacements of components to the power supply and the Audio stages, as well as the currently defective digital readout (missing LED segments). Once it is done, I will get a nice antennae connected and will enjoy some local classical radios from time to time.

Yves
 
Brian,

If you have the schematic of the Digital readout section for the 8000, could you post it?

I only had the Mark VIII schematic and there are a few differences with the 8000 Tuner. For instance, on the Mark VIII, the main switch cuts the primary of the transformer, whereas on the 8000, it is the secondary which is switched.

I have reworked my 8000 to have a power supply more in line with the Mark VIII as I do not like to leave the transformer on at all times.

Yves
I actually have the Mark VIII production date May 6 1977

I can't post the digital readout it's a too large PDF, so I need a mailadress.
 
Thanks to Jim from Jim's SAE site.
He should have the credits for these schematics.
I made a donation for 'Southern California Dachshund Rescue & Nowzad Dogs' to get these items.
So he will supply you with SAE items and you can make a donation.
It's a matter of trust of course...
 
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Regarding the LEDs replacement on these TUNERs, I worked on mine yesterday and replaced all 4 displays with Lite-On LTS-3401 displays from Jameco ($1,09 each). The result was fantastic, very bright and easy to swap. You just have to cut the unused Pin for the extra decimal dot.

Instead of wasting your money on "rare", overpriced and outdated DL-747 modules, go with these ones. At $4.40 plus 15 minutes of work, you cannot go wrong.

Yves
 
Great, I got a couple of HPDS-3400's, the standard compatible device according to SAE, in reserve in case of...
Strangely my Mark VIII has already a newer LED board and all the LED segment resistors in front of them have already the higher values (180 Ohm > 270 Ohm, for the LED segments, 240 > 330 Ohms for the decimal point) although it's one of the first units.
It doesn't look that some DIY'er (haha ;-)) did the conversion.
I still have the two 10nF Styroflex caps in for the USA 75us deemphasis and SAE advises to change them to 5nF for the rest of the World (except for Korea I believe) 50us.
Does it make a lot of difference, I operate the unit in a secondary system for background purposes...
 
Folks,

I have completed the rework of my SAE 8000 FM tuner. Basically, I did the following:

1) Replace the old DL-747 (a lot of segments were burnt out) with new LITE-On 3401. Result is stupendous and will only cost you $4.40 with Jameco. The original unit had already the new board with 270 ohms resistors marked on the PCB. The new display is very bright and sharp.

2) Rewire the Power supply and use the switch to cut the primary of the transformer, instead of the secondary.

3) Replaced all the wiring going to the outputs and 5 RCA plugs on the back. I could not stand these cheesy pieces of wires that came with the original tuner.

4) Replaced all components of the power supply and increased the size of some caps. Installed metal resistors of higher wattage on the supply. Replaced the cheesy power cord with a three prongs modern one.

5) Replaced all chemical capacitors on the board, and installed bi-polar caps on the signal path.

6) Installed two new belts to drive the tuner wheel. I found these at ACE and they have one that is large enough to accommodate the SAE mechanism. There are two gouges in the button axle, and the two belts will fit nicely, giving more grip and durability.

7) Cleaned all parts and dusted off all PCBs.

The tuner works like a champ and the sound improved drastically (35 years polarized caps are no match for modern bi-Polar ones). The basses are very authoritative and the treebles are crisp and precise. I listened to a mix of material, Top-40 and classical, as well as a lot of voice and it is a pleasure.

Overall, I probably spent about $30 in components and a few hours of work. Definitely worth it.

Yves
 
SAE 8000

Hi Yves,
I enjoyed reading your post on restoring/updating your SAE tuner. I am preparing to start the same for my 8000. I wasn't quite sure where you got the replacement belt. Could you post that info and maybe a part number ? Also, what did you mean by the comment about the gouges in the drive wheel ?

Thanks,
Dennis
 
LTS 3401

Hi Guys,
It appears that the replacement LED Displays ( LTS-3401 ) are no longer available from Jameco. I have checked with Digikey, Newark and several other popular suppliers but to no avail. Does anyone have any ideas where to purchase these displays?

Thanks,
Dennis