I felt SRI for you getting no responses, so here's what I found when I
opened up my 4K-U.
1. The resistor that is referenced as R112 is a wirewound adjustable 10 ohm
2. R112 is wired slightly different than as shown on the schematic. The
bottom end (as shown on the schematic) goes to R113, as shown, but the
slider goes to pt.a (coil of the overload relay) and the R111 bottom
junction. The top of R112 is open.
3. R113 is 75 ohm 20w and is wired as shown.
Therefore it appears that the schematic is "basically" correct and the P/L
4. Also, Figure 6 (page 15) is incorrect where it shows D110 and D111.
These s/b respectively R113 and R110. D110 & D111 are tied to the terminal
strip on that sub-assembly.
Note: My 4K-U is S/N 05-230 and the power supply is S/N FD-114. The only
modifications I have made was to replace the original HV filter cap with a
40mf 6KV unit and sound isolate the big blower from the chassis. The PA has
been essentially bullet-proof. I hope this info is beneficial.
----- Original Message -----
From: "Bob Maser" <email@example.com>
To: "AMPS" <firstname.lastname@example.org>
Sent: Wednesday, June 28, 2006 7:24 PM
Subject: [Amps] Henry 4K-Ultra Schematic Error
> I didn't get any replies to my original post so here it is again.
> On the schematic of the power supply (page 25) it shows that R112 is 15
> 75 watts and R113 is 75 ohms 25 watts. On the list of parts on page 20
> R112 and R113 are listed with the values reversed. Which is correct?
> It's strange how some people carry on and on and on with some of these
> worthless threads and yet ignore some inquiries that could be easily
> answered. I don't have the statistics but it seems to me that the number
> posts on this AMPS reflector has quadrupled during the last year.
> Bob W6TR
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