[1000mp] Again: deaf receiver

[dl8uf at darc.de]

Hi you OM and YL/XYL out there,

Casually destiny knocks at your door, just to say 'hello' and leave you a
little gift. Just at the right time, in midst of the K5D Dxpedition*), it
was my door where it knocked. I was facing the problem already discussed
here for several times: after keying in CW/QSK the receiver suddenly is
deaf, which sounds like a sensitivity loss of about 30 or 40 dB. Some dits
on the keyer may stop this problem and the noise floor or the wanted signal
is back again.

A search through my archive of this forum resulted in the assumption, that
the T/R relay might be the culprit. A brief look into my "HF Transceiver
Mark-V FT-1000MP Field, Technical Supplement" let me find the following
description:

[Quote]
High-Frequency Circuit
The receive signal enters from ANT connector A or B, selected by relays
RL6452/RL6453 on the TUNER-MAIN Unit, and it the passes through t/r relay
RL6451 and is fed to connector J1003 on the RF Unit from connector J6454.
[/Quote]

After searching for relay RL6451 in the schematics and the parts lists for a
remarkable amount of time, without being successful, I got the strong
suspicion, that there might be something wrong with the component
identifiers either in the describing text or in the schematics/parts lists.
To prove that, I tried to locate the (antenna selector) relays
RL6452/RL6453, which was much easier, because there are only a couple of
components mounted on the ANT Unit board including the two relays. Damned
... (censored), in the schematic and the according parts list, these two
relays are not identified as RL6452 and RL6453, but as RL8801 and RL8802.

1.) Does anybody know the correct identifier of the T/R relay in the
schematic and parts list and on which board it is located?

2.) Has anybody changed this relay in a Mark-V Field and successfully solved
the deafness problem? If so, what kind of relay did you use and where did
you buy it?

Looking forward to your input,


73 de Uwe, DL8UF


*) For those who are interested: although I had this receiver problem,
luckily I was able to work K5D on 30m and 20m with 100W and windom antenna.
Destiny had already knocked at the next door, hi.