HM-2140 wattmeter

[Emil Dular]

For the next guy, here is what I found:

Meter pegging problem caused by failed IC U1 Heath P/N 442-602. Replaced
with Mouser 512-LM324N. (32 cents).

Bad 20K trim pots Heath P/N 10-390 at R5, R13 & R14 were replaced with
Mouser 531-PT15B-20K (45 cents each)

Capacitor C11, Heath 21-176, a .01 mF 1KV ceramic disc failed open. Part
number 75-562-R10TSSS10 (77 cents) was used to replace it.

The replacement chip and trim pots fit exactly the PCB footprints of the
originals. Calibration was then easy and accuracy is excellent.

73   Emil WD4SCZ


Starting to troubleshoot an HM-2140 wattmeter.  No matter what else you do,
if the REFLECTED meter switch is "out" in the REF position and push in to
the PEP position the REFLECTED meter pegs.  If you turn the SENSITIVITY
control all the way CCW and push in on PEP it checks the battery level like
it should, but still pegs the reflected needle.  Adjusting the reflected
null pot has no effect.

-----------------------------------------------------------
Products bought, sold or traded here is the responsibility of the
parties involved.  This list and the City of Tempe are not responsible
for losses or misrepresentations of any kind.  Buyer beware!

-----------------------------------------------------------
This list is a public service of the City of Tempe, Arizona
-----------------------------------------------------------

Subscription control - http://www.tempe.gov/lists/control.aspx?list=HEATH
To post - HEATH at LISTSERV.TEMPE.GOV
Archives - http://listserv.tempe.gov/archives/HEATH.html