Author Topic: Guess what followed me home yesterday  (Read 152 times)

AlanInSitges

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Guess what followed me home yesterday
« on: October 27, 2018, 10:00:21 AM »
...after me and three other guys heaved it down seven flights of stairs and into the back of a van.

https://photos.app.goo.gl/p1ujbYsU6Zh2EvcT7

It's a Grundig KS690 from 1965, with a Dual 1090 turntable (good grief that platter must weigh 20 pounds), two reel-to-reel decks, and the original factory stereo microphone still in its box. The guy I bought it from (150) said it came with his flat when he bought it, the previous owner thought it was too heavy to take it with him. It's been sitting there in the guy's living room for 25 years unused. It's got the ELL80/6HU8 outputs instead of the 6BQ5, but still, it looks pretty awesome to me.

As you can see from the photo it was a busy shopping trip so I haven't had time to try it out yet, but I'll start a thread when I start the restore.

chazglenn3

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Re: Guess what followed me home yesterday
« Reply #1 on: October 27, 2018, 10:25:59 AM »
Wow! Two reel-to-reel decks?  Sounds awesome!  Congrats!
Charles
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Re: Guess what followed me home yesterday
« Reply #2 on: October 27, 2018, 12:53:45 PM »
Enjoy your Grundig!  Most of the ones I've seen are black lacquer, but Yours will be very nice once you do the clean and polish routine.  Those ELL80 tubes are rather expensive, but at one time Grundig made an adapter that converted the output from a single 9 pin ELL80 to two 7 pin sockets that were fitted with EL95 tubes.  The 7 pin tubes are much less expensive, but finding the adapter is like finding a needle in a haystack.  The electrical characteristics of the EL95 is the same as one half of the ELL80 tube.  I ended up making my adapters.
Another problem you may encounter is with pot metal and the dial stringing.  The issue is all mechanical as the pot metal just breaks apart.
I've only worked on a couple of German radio and stereos, but once they are working, they really do sound great, and the radios are quite sensitive.  You really have a nice console there.

Here's what I ended up using for the output tubes, it's not pretty, but it worked well.

Motorola Minion

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Re: Guess what followed me home yesterday
« Reply #3 on: October 29, 2018, 02:40:13 PM »
That is an interesting model. KS stands for Konzert Shranke (concert gate). The KS-490 was pretty popular because info is sparse for the later KS models. I have read too that the tuning and band switch mechanism is an issue.

I have the one before it, KS-590 WE for 1964, which has the NF-2 amp chassis w/PP 6BQ5. It was in an outdoor shed for years when I got it. finish is ruined but its complete, not water-logged and shows no evidence of rodents.

Are you sure the ELL80 tube is used as the final audio stage? You may have transistor output stages.

I have a Fisher A-69 that uses two ELL80/6HU8 for dual AF driver transformers, for 8 transistor outputs.
Tubes - Magical - Tubes

Dave

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Re: Guess what followed me home yesterday
« Reply #4 on: October 30, 2018, 10:19:15 AM »
On the Grundig I had I know it had the ELL80's because it was purchased by the friend I know while he was stationed in Germany.  It was interesting to note that the German model used the ELL80 and the ones Grundig exported to the USA had the EL95's.  There were two additional holes punched in the chassis that weren't used on the one I was working on.  Even the Sam's showed that the US version had the EL95's for output tubes.  The SO360 model was a 1963 model and I don't think the transistors were in use until a couple of years later.  All I know is when I gave it away it worked very well.  I was happy to clear up the room.  Sometimes this hobby really doesn't pay well, but I'm not in it for the money.  The mechanics on those sets are a challenge, especially the dial cords.

I did see the use of the ELL80 in the Fisher stereos and can't think of a good reason why they used them.  Only reason I can think of is some sort of impedance matching as the grid input would be high and being it is a cathode follower, the output would be low.  Interesting circuitry there as well.

AlanInSitges

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Re: Guess what followed me home yesterday
« Reply #5 on: October 31, 2018, 08:50:29 AM »
Thanks everyone! It's definitely got ELL80s. I have managed to track down a couple of NOS tubes just in case, though I haven't started the restoration of this set yet. I see you can also use a PLL80, which is the same with a 12-volt filament and muuuuch cheaper. So maybe in the future it's worth subbing a small 12V transformer for the output filaments.

I got into the tape side today and have a couple of photos of the RtR machines. I'm guessing the older one in the cool case is a mono unit? The other one is a TM45, which appears to be stereo and maybe the original one? The curious thing is that both decks were just sitting in the cabinet. The entire left-hand side is just like a coffin storage area, but the TM45 was without any case, like it was meant to be dropped into a cabinet. It's all very curious.

I'm really looking forward to getting started on this! I have a Predicta and another TV on the bench first though.