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!

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

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

Shack 2.0 Project: Second Part

Well, once workers were gone, I started working on the shack. I have put a new WEB page to document these works:

EB5AGV's Shack 2.0: Second Part

Here you have one picture of the current looks. Of course, still a work in progress:



73 JOSE EB5AGV

Shack 2.0 Project

INITIAL CONDITION (1/OCT/2009)



UPDATED PICTURE (6/NOV/2009)




UPDATED PICTURE (13/NOV/2009)


Well, I am now in the middle of the shack rework!

I have put a new page in my WEB at:

EB5AGV's Shack 2.0 Project

I will update it frequently, so keep connected!

73 JOSE EB5AGV

New addition to my RF lab: HP-8566A

Well, it has been (and continues to be) a big deal to have it working, but here you have my last addition to my RF lab: a 100Hz-22GHz HP-8566A Spectrum Analyzer


You can read about the repair and see plenty of pictures of the process at:

EB5AGV's Workbench: HP-8566A repair

Best regards,

JOSE

Ten-Tec Paragon

I own a number of radio rigs from lots of different manufacturers (Yaesu, Kenwood, Icom, JRC, Drake, Collins, ...) but, until yesterday, I had no Ten-Tec in my collection. So my new Paragon is for me, besides a new toy, my very first Ten-Tec. I have fixed several Ten-Tecs over the years but I had none of my own.

This unit arrived in pretty good shape, with only some light dirt on it. I bought it as unworking in AM mode and generating extrange sounds at low frequencies. Obviously, I suspected of PLL problems as they are well documented all over the WEB... Well, I have not found yet any obvious problem with the rig in both aspects!. So I guess there could be an intermittent fault waiting to develop again.

Unit arrived with original User Manual (nice one, more like a Service Manual) and a non-original hand mike (which seems to be wired wrongly). It has an optional FM module, but no RS-232 module and no extra filters. Here you have some internal pics:




Only sign of previous repair I have located so far (I have not yet opened lower inner cover) is around the backup battery charging (I guess) circuit. BTW, battery holds a charge but memory and RTC are reset when power is out. So something is wrong here:



Despite the inclusion of the original Giehl EPROM manual in the back of the User Manual, this unit has an standard Ten-Tec EPROM on it, version 3.9:


I wonder if someone would sell me a Giehl EPROM...

I need to check the unit in detail but, so far, it seems to work pretty nicely.


UPDATE #1

I have just opened the inner bottom cover to check. There are good news!. Unit seems completely untouched. GREAT!!!

Here you have some pictures:




And now some more detailed pictures: this is from the PLL area. I have found that wiggling these connectors warbles the signal but this could be due to stray induced capacitances:

And this is the antenna discharge protection:




I will add more info as my work progresses.

73 JOSE EB5AGV