[1000mp] Again: deaf receiver

[Garry Shapiro]

I just checked my FT1000MP Technical Supplement and the description 
matches /neither /of the designator sets you list. So I suspect that, 
although certainly much of the circuitry must be shared between the MP, 
Mk.V and Field, there are major differences. Your manual may not be 
correctly updated.

It is probably a good idea to replace all of the front-end relays, since 
they appear to be the same and thus equally likely to fail. I just had 
an early MP repaired and mentioned the dropout problem, so the 
technician replaced seven relays.

The repair outfit I used was Byron Campbell, WA4GEG in Tennessee. He may 
answer your questions for you.

Garry, NI6T

dl8uf at darc.de wrote:
> 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.
>
>
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