[Test-Equipment] HP-436A Power Meter

[George, W5YR]

FWIW, the 436A also has an uncalibrated analog meter to show relative signal
levels.

The sensors used in this series of power meters are thermocouple devices
that are exceedingly "tender" - I know! I accidentally left my HP 606A
signal generator connected to my low-power sensor overnight and trashed the
sensor. The power output was only microwatts, much lower than the maximum
rating of the sensor, but over several hours that was enough to do the
damage. That sensor sells at a local test gear facility for nearly $2000.

The 436A is a marvelous machine but the sensors are the heart of it as well
as the principal cost. I would not buy a sensor on Ebay unless guaranteed in
writing to be returnable for refund if DOA. But no sensible seller is going
to allow that because of the ease with which the buyer can toast it and then
claim DOA. There is no solution to this other than to accept the risk as
either buyer or seller.

Caveat Emptor rules still . . .

73, George W5YR
w5yr@att.net
http://www.w5yr.com


----- Original Message ----- 
From: "Dennis L. Wade" <dwade@pacbell.net>
To: "Bill Miner" <wg6h@postoffice.pacbell.net>;
<test-equipment@mailman.qth.net>
Sent: Thursday, February 26, 2004 9:21 AM
Subject: Re: [Test-Equipment] HP-436A Power Meter


Thanks to Bill, Dino and everyone who replied.  I really didn't
expect such a quick and detailed response...what a nice surprise.

I appreciate the analog vs. digital comments.  I prefer the moving
needle to a digital readout in most cases.  Dino said that the real
issue with the '436 is the cost/availability of the power sensors and
cables, often far exceeding the cost of the meter unit itself.  Much
care has to be taken with purchasing used sensors; "...there are lots
of blown power sensors out there..."

But one thing confuses me a bit...seems both the '436 and 435 use the
same 84XX series power sensors?  Looking at ebay histories (which has
its own problems)  the '435 power meter itself seems to go for
somewhat less, but the same issues remain for the power sensors, i.e.
cost and availability?  Lots (by comparison) of meters for sale, very
few sensors.

      Thanks again for all the replies.

Dennis

> Dennis,
>
> You have been given some very good advice by Dino KL�S/4.  I concur
> with everything he told you.  If you can find an HP-435B that is in
> good shape you will be pleased.
>
> GL
>
> Bill - K6WLM
> Sacramento, CA
-----------------
"If you can remain calm, you just don't have all the facts"

Dennis Wade
KG6ZI
Carmichael, CA

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