After the visit of Menahem at my home i'd the opportunity to see inside the 3400. I helped to do the final tuning of the FM tuner. Now let's go back to my 609K. After recalibarting the FM tuner it's look very good. I replaced the ECC85 to E88CC and now i have 6db more gain. The EF89 was changed to EF183. Now the FM receiver works very good

Hi Martin, very intersting! see the picturs below... btw,the pictures in nasa site are of the same type of capacitor as mine...

Hi Martin. Some good news here... I found the problem in the FM tuner. it's a long story... any way, I decided do disassemble the tuner from the radio, to make it easy to track the problem. First, please note that the schematic you sent me is not as my tuner ! there is some variations. Second, i found that one part of the variable capacitor have

Thanks!!! i opened the tuner cover. i'm testing the voltage on the tube, all looks ok. this tuner is very very uncommon in it's circuit. the oscillator/mixer is the right tube and the left tube is the RF amp. (correct?) few caps, around L102 and may be the Varicap of the AFC are suspects IMO. (i will continue on th enext day)

No the FM tuner is not working yet. the test was done by injecting 10.7MHz FM signal from RF generator to the output of the tuner., so all the IF link can be checked and calibrated again. this is my general work with old FM radio's.

The E88CC was replaced in my Balupunkt Sultan FM radio, that i restored few weeks ago. I remember that the sensitivity of the radio was increased after changeing the original ECC85. as noted , I didn't noticed any suspected components yet. I see that I need the manual...(any help?) i will try later this evening to continue my work. Regarding the

Martin, Thanks for the fast reply, please note that I'm Ham radio too, and strated my hobby at the same date as the tubes in the B&o radio....I have very good experience with tubes, note that the moment i saw the radio for sale I knew i'ts something good... when i looked on the back I saw the tubes list, wow, it has 2 push pull amplifiers

Hi, just found on last Friday in Te-laviv flea market, (wow, it's a rare item I think...) for about $60 a Grand Prix 609 K Moderne radio. Cosmeticaly it looks good, one small knob is missing, and no speakers included... All the tubes inside are original with a B&O date sign: APR. 1963, and one ECL86 is BY Haltron Problems (for now) 1. The FM