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Hi Everyone,

I just joined the group, and am already posting a question, hoping somebody would have some information to share...

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I just acquired (salvaged/got from somebody who wanted to get rid of) an old FT-101 (Sommerkamp FT-277) which I set out to restore; the first thing I noticed was that in place of the PB1080A board, the last owner had installed an unknown board with a marking P04-004 - it looks very similar to the PB1080A, with the NB and a homebrew SSB filter, but the markings of the transistors are long gone... A search on the web has given nothing...

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I was wondering if anybody had any information about this board (link, schematic, etc)

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Many thanks and 73s, Joseph F4JVO

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Hi Joseph,

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That is very interesting!

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The P04-004 is a valid Sommerkamp board number and is the IF board from the Sommerkamp TS-288A transceiver, which was the Sommerkamp version of the FT-101 with added CB channels.

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This board should be very similar to the PB-1080A and I have attached a schematic of P04-004. I have not checked that these boards are interchangeable, but I believe that they would be. I believe that the original board would have had the Yaesu SSB filter fitted. I do not know why yours has a homebrew filter. Perhaps the original filter was somehow damaged, or a previous owner wished to improve the performance? The early FT-101 and TS-288A were fitted with a 6-pole SSB filter, whereas later models of the FT-101 used an 8-pole filter.

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73,

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Peter

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G4DJB

Hi Joseph,

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Attaching that schematic to my message didn't work as the quality of the image was degraded. I have placed a copy of the P04-004 schematic into the Files section of the group. The file name is P04-004.jpg.

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73,

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Peter

G4DJB

Thanks Peter,?I really appreciate your reply!

I was very surprised about the lack of any information on the web about that board. I even asked a few Swiss OMs, but somehow nothing came out!!!

The main reason I enquired about that board was that the S-meter somehow stopped working; then, I realized that the 500ohm pot was damaged, and when I replaced it, an evil-looking smoke came out of 'somewhere' and the S-meter was still dead...

So, I suppose the next step will be to replace the 2sc828q transistors (wish me good luck!).

Thanks again, have a nice weekend!

73 - Joseph F4JVO?

Hi Joseph,

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Good luck with the repairs!

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There could be little information on the web as the TS-288A was not made in great quantities, and this is the first time that I have heard of a board that should be in a TS-288A being put into a FT-101. The full manual with schematics for the TS-288A is available on the web if you are interested.

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Another manual I have shows the BC182 as a replacement for the 2SC828Q, but you will need to check the pin designations to make sure it is a good replacement.

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73,

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Peter

G4DJB

Thanks Jim for your help!

I fully agree with you, that's the obvious way to go; I only quoted the transistors because I believe this is going to be the main source of difficulties (substitutions, etc).

In the meantime, I located a 'fried' resistor, which was probably the source of the smoke; I will replace it and see what happens next...

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BTW, note that repalcing the PB1080A with a P04-004 on a Sommerkamp Ft-277 doesn't seem to affect the RX quality; at least, I haven't noticed any difference, when comparing to a FT-277E...

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Thanks again to all!

73 - Joseph F4JVO

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