I have added a new page to my WEB about the repair of a seriously ill Yaesu FT-1000MP MKV
You can check it at:
http://jvgavila.com/ft1000mpv.htm
73 JOSE EB5AGV
25 October 2010
24 May 2010
Worse than the H1N1... ceramic filter pandemic
Well, it could be a false alarm (pun intended) but lately I have been getting more and more rigs for repairs, and from diferent manufacturers, with bad Toko black ceramic filters (6 and 9 kHz by now)
I have fixed three rigs in the last few weeks with this problem, two Yaesu FT-897 and one Kenwood TS-2000. Symptoms could range from lower sensitivity, to cracking noises and, usually, you have both. There is also an interesting effect, at least on FT-897s, which is that they receive in DSB instead of SSB when filter fails.
I have opened one filter and it had some greenish looking residue on it, so I guess sealing had failed and moisture did the dirty job.
I would be interested in hearing other people experiences with those small "BLACK NOISIES" (*) (remember you saw it first here, (c) EB5AGV ;-) )
Best regards,
JOSE
(*) the equivalent to "BLACK BEAUTIES" caps in old boatanchors!
I have fixed three rigs in the last few weeks with this problem, two Yaesu FT-897 and one Kenwood TS-2000. Symptoms could range from lower sensitivity, to cracking noises and, usually, you have both. There is also an interesting effect, at least on FT-897s, which is that they receive in DSB instead of SSB when filter fails.
I have opened one filter and it had some greenish looking residue on it, so I guess sealing had failed and moisture did the dirty job.
I would be interested in hearing other people experiences with those small "BLACK NOISIES" (*) (remember you saw it first here, (c) EB5AGV ;-) )
Best regards,
JOSE
(*) the equivalent to "BLACK BEAUTIES" caps in old boatanchors!
31 March 2010
R&S NV 1/156 VHF Multi-coupler
This is one project I had stored for a long time... I got the unit some time ago and worked on it to fix some transport damage and clean it:
EB5AGV's Workbench: Rohde & Schwarz NV 1/156 VHF MULTI-COUPLER repair
But, as I said in that page, it was deaf and, suspiciously, one of the tubes, an EC80 UHF triode, measured low in the unit's own multi-meter (a great idea, BTW)
Finally, I got some EC80 spares and was able to check it. Wow!!!. This unit was manufactured in 1966 so it is 44 years old (2 more than myself, hi!). But it still works fine and, even if its noise figure is for sure higher than the modern equivalent, as it is specified from 100 to 156MHz, it is perfectly usable for FM broadcasting, monitoring air band (around 120MHz) and, of course, 2 meters ham band.
Here you have one picture of the unit, still cover less, connected to two rigs:
The multi-coupler has 5 outputs so I will add more rigs to it and use as a monitoring system.
It is great to mix old technology with 21st century rigs :-)
73 JOSE EB5AGV
EB5AGV's Workbench: Rohde & Schwarz NV 1/156 VHF MULTI-COUPLER repair
But, as I said in that page, it was deaf and, suspiciously, one of the tubes, an EC80 UHF triode, measured low in the unit's own multi-meter (a great idea, BTW)
Finally, I got some EC80 spares and was able to check it. Wow!!!. This unit was manufactured in 1966 so it is 44 years old (2 more than myself, hi!). But it still works fine and, even if its noise figure is for sure higher than the modern equivalent, as it is specified from 100 to 156MHz, it is perfectly usable for FM broadcasting, monitoring air band (around 120MHz) and, of course, 2 meters ham band.
Here you have one picture of the unit, still cover less, connected to two rigs:
The multi-coupler has 5 outputs so I will add more rigs to it and use as a monitoring system.
It is great to mix old technology with 21st century rigs :-)
73 JOSE EB5AGV
20 January 2010
Shack 2.0 up and running!
Well, I have finally my new shack setup!. It is an ongoing work but I have been able to work on half a dozen rigs so far on new workbench.
Here you have a picture of myself (courtesy of my friend Alf, EA5AMM) at the controls of the Enterprise... err, workbench :-D
More repair works to come soon!
73 JOSE EB5AGV
Here you have a picture of myself (courtesy of my friend Alf, EA5AMM) at the controls of the Enterprise... err, workbench :-D
More repair works to come soon!
73 JOSE EB5AGV
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