[1000mp] RELAY INFO

[Cecil Acuff]

Bob and Group,

    I have complete documentation on the MP but not the MK V.  There 
probably is not a lot of difference in that section but I may be wrong.  I 
find five relays in the receive path that could cause problems:

RL8701 P/N AG2013 used as Antenna A select relay.  There is an identical 
relay used as Antenna B select relay. (RL8701) A nearby lightning strike or 
static charge on the antenna system could have damaged the contacts in the 
Antenna A relay.  One test would be to connect your antenna system to the 
Antenna B input on the rear and select antenna B for a while and see if 
problems continue....or the next time it fails operate the ANT A/B switch 
several times and see if it restores receive sensitivity.  These are located 
on the ANT-UNIT.  This is the first relay exposed to the antenna system so 
it might be the culprit but it's not switched a lot so I would more suspect 
the next relay in my list....

RL6016 P/N AE5343 used as the T/R switch and located on the LPF-UNIT.  This 
operates every time the PTT is operated and would be my main suspect.

RL1001 P/N AGY2323 used as the RX antenna switch.  Like the first two not 
operated often so down on my list of suspects but certainly possible.  As a 
test next time it fails operate the ANT RX button a few times and see if it 
restores receiver sensitivity.  This relay is located on the RF UNIT.

RL1003 and RL1002 both used to switch in 6db and 12db of attenuation 
respectively.  Combined gives you the 18db.  Could make the receiver appear 
to drop in sensitivity by 6 or 12 db but I wouldn't expect 18 because that 
would require failure of contacts in both relays at the same time which is 
not likely.  A test would be to switch the attenuator switch through it's 
full range a couple of times the next time it fails and see if that restores 
receiver sensitivity.  These relays are located on the RF UNIT.

Another thing I would do would be to operate the radio with the cover 
removed and tap lightly on these relays when in failure mode and see if you 
can isolate the culprit that way...

Use an insulated tool handle or such.

My #1 guess would be the T/R switch.

I don't think the relays are anything proprietary and replacements should be 
easy to locate.  I know one manufacturer, Omron, makes a range of relays 
that might fit the need...I would look in the Allied or Mouser catalogs for 
replacements.

Hope that helps a bit....again if the MKV is completely different sorry for 
any confusion...so far I have not had relay problems in my early MP.

Cecil Acuff
WB5VCE

----- Original Message ----- 
From: "Bob Scott" <w4zy at bobandpenny.us>
To: "All about Yaesu 1000mp" <1000mp at mailman.qth.net>
Sent: Tuesday, September 05, 2006 8:10 AM
Subject: Re: [1000mp] Relay thing..deaf receiver


>I keep reading this thread in hopes of obtaining more information about the 
>relay issue.
> 73,
> Bob
> W4ZY
> ______________________________________________________________
> 1000mp mailing list
> Home: http://mailman.qth.net/mailman/listinfo/1000mp
> Help: http://mailman.qth.net/mmfaq.html
> Post: mailto:1000mp at mailman.qth.net
>