KLH Model 21 found at Goodwill today!

[zeno]

KLH built some very nice stuff. Our shop saw a lot
of it being 20 miles from Cambridge. Also piles of
H.H. Scott that was 5 miles away.
Anyhows change ALL the lytics first. I remember a few
of the stereo ones going DEAD in one channel & that
was it. ( 30 yrs ago ). Another thing that may be it
is if it uses ua703 IC's in the IF they were trouble
especially on Scotts sets. In any case when its running
again you will wonder what all the hoopla about digital is.

73 Zeno

[Captainclock]

Originally Posted by zeno

KLH built some very nice stuff. Our shop saw a lot
of it being 20 miles from Cambridge. Also piles of
H.H. Scott that was 5 miles away.
Anyhows change ALL the lytics first. I remember a few
of the stereo ones going DEAD in one channel & that
was it. ( 30 yrs ago ). Another thing that may be it
is if it uses ua703 IC's in the IF they were trouble
especially on Scotts sets. In any case when its running
again you will wonder what all the hoopla about digital is.

73 Zeno

I believe mine's an original 21 so I don't think it has any IC chips in it. The electrolytics don't appear to be bad but of course they could be bad even if they don't look it (no cap bulge). The electrolytics are mainly on the amplifier board, there aren't any on the tuner board surprisingly enough. Now I noticed that the Model 21 has an RCA Plug that says "Tuner out" was this meant to be able to have a multiplex unit hooked up to it so it could be FM Stereo like the Model 8? Also I'm missing one of the knobs on this unit and I was wondering where I might source a replacement knob for this unit.

[dieseljeep]

Originally Posted by Captainclock

I believe mine's an original 21 so I don't think it has any IC chips in it. The electrolytics don't appear to be bad but of course they could be bad even if they don't look it (no cap bulge). The electrolytics are mainly on the amplifier board, there aren't any on the tuner board surprisingly enough. Now I noticed that the Model 21 has an RCA Plug that says "Tuner out" was this meant to be able to have a multiplex unit hooked up to it so it could be FM Stereo like the Model 8? Also I'm missing one of the knobs on this unit and I was wondering where I might source a replacement knob for this unit.

The ua703, if made by Fairchild, looks like a slightly larger transistor. The brown button ones were extremely unreliable. IIRC, they were replaced by a GE-IC12, NLA.

[Captainclock]

Originally Posted by dieseljeep

The ua703, if made by Fairchild, looks like a slightly larger transistor. The brown button ones were extremely unreliable. IIRC, they were replaced by a GE-IC12, NLA.

So What's the modern substitute for this part? Is there an NTE Part that subs out for this part?

[WISCOJIM]

Some members here may still have some epoxy ones in their parts bins, but you may have to substitute one of these metal ones:

http://www.amazon.com/IC-AMP-8-LEAD-...productDetails



.

[jr_tech]

Am I missing something here? I don't see any ics in the schematic for the set... just 11 transistors

jr