HW-8 is Microphonic and need schematic.

[MVD@MVD]

Isn't the microphonic behavior typical of the HW-8 (I'm asking the group)?

Of course there's nothing wrong with finding a solution. I had one & think I
remember the same thing.

Murray
----- Original Message -----
From: "DARYLE BROOKS" <wb7tne.brooks at WORLDNET.ATT.NET>
To: <HEATH at LISTSERV.TEMPE.GOV>
Sent: Sunday, July 28, 2002 4:23 PM
Subject: HW-8 is Microphonic and need schematic.


Hello To all. I have aquired an HW-8 in good cosmetic condition. I made up a
new
dc power cable and fused both legs. Plugged in and turned on .
Received,although poorly,connected to a triband yagi. It has exhibited a
microphonic problem wherein
if you tap on the outside case it can be heard in the audio output. I
removed the upper and lower cases and tapped around lightly on the main
board. I had the same results. The noise is most pronounced on the largest
of the three cans with
the tuning slug inside. I can isolate the two smaller shields mechanically
with my fingers and tapped on the largest shield and it seems to be the
center of the problem there. Also ,if you move the antenna connection ,even
slightly,or touch the center connection in side the case,the same  occurs
and the received signal goes up or down when the antenna connector is not
touched/coupled to myself.Very minimal output on rf into a 50 ohm laod,on
the order of 300 milliwatts. I have reworked some of the few poor solder
connections and nothing was improved by reflowing the solder points. I don't
have a schematic .Where do I look for one and where is best place to start
on this. I bought this in supposed "working order" so ,I guess the old
addage of a sucker is born every minute! Thanks for any help.

TNX
Daryle

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

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

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

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