[1000mp] Again: deaf receiver

Wed Mar 4 02:11:27 EST 2009

Hi Garry,

Thank you for your fast reaction. Nice to hear from you again.

Byron Campbell, WA4GEG in Tennessee might be a good address. Of course it
seems to be inadequate to ship the TRX from DL to TN for repair, but maybe
he can give me some useful advices amongst hams.

We have a very sad situation with Yaesu repair service in EU. It is about to
be reorganized. In the last edition of the most popular German ham radio
magazines (cq-DL, Funkamateur) there was a report about the planned
structure of the service net in EU. A ham and smaller ham radio dealer, who
lives only about one hour away from my qth, was mentioned to give repair
service at least for DL, OE and HB9 in the future.
So I have also sent an email to him, described the problem and asked whether
this problem is well known to him and how he estimates the effort for
repair. His answer was not very encouraging:

- It was planned, that I should give repair service for dealers only, NOT
for end users.
- After the magazine reports I get more than 200 emails per day. I'm not
able to answer them all, got no more time for my job. So the plan will stay
was it was: just an idea. I will not do this job.
- Send your TRX to the dealer where you bought it.
- The reason for the problem seems to be the "famous diode on the RF board".
Very complex to repair, because the TRX has to be widely disassembled.

Beside the fact, that Yaesu Europe is far from being well organized, there
was the fact, that he mentioned this "famous diode on the RF board".

As far as I remember, a diode was never mentioned in all discussions about
this problem here. And it seems to be more obviously that torn contacts of a
relay cause the problem. But on the other hand, this guy does radio repair
for about 40 years now.

All in all, this answer raises more new questions than it answered :-(

73 de Uwe, DL8UF

-----Ursprüngliche Nachricht-----
Von: 1000mp-bounces at mailman.qth.net [mailto:1000mp-bounces at mailman.qth.net]
Im Auftrag von Garry Shapiro
Gesendet: Dienstag, 3. März 2009 22:06
An: All about Yaesu 1000mp
Betreff: Re: Again: deaf receiver

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.
>
>
> ______________________________________________________________
> 1000mp mailing list
> Home: http://mailman.qth.net/mailman/listinfo/1000mp
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:1000mp at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>
>   
______________________________________________________________
1000mp mailing list
Home: http://mailman.qth.net/mailman/listinfo/1000mp
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:1000mp at mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html