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    HH Scott 348 B

    https://www.youtube.com/watch?v=p3_qSo7Ig8Q Done
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    HH Scott 348 B

    I started the process of ID'ing the caps to see what I needed, making up little bags of caps to go with each of the boards. For grins I checked one of the 47uf 75v caps on the main driver board, totally open, which is suspect is going to be the case. I plan to replace all since I am pretty sure...
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    HH Scott 348 B

    looking for a schematic on this. https://www.youtube.com/watch?v=oXP4vTuiFEU it was a freebee and I kinda want an early SS stereo to listen to. I could prob recap it mostly without a schematic, but some of the caps have plastic covering that has disintegrated and I can't read whats...
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    fisher 400 eye tube

    did the ant swap from local to normal, only change was more distance stations had a weaker lock on the MPX. did swap the eye tube from the other set, no change in closure just dimmer (the 3 tuber eye is not a bright).
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    fisher 400 eye tube

    Dave, after I sweep that Z1 one more time I will reconnect the resistor and see how it all looks. I just want to make sure its max peak is at 10.7 (z1 only) as I have a few more cap to try if it does not. the video is loaded now (33pf on Z1 no resistor), more to come as I experiment with it. I...
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    fisher 400 eye tube

    http://youtu.be/Bm1y7C2jU84 its still loading so should be ready in a few this is where I am now. this is with the resistor lifted, the only diff with it attached is the eye is maybe 1/8" open on the very strongest signals. I am having to learn about antennas as well, this uses a pair...
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    fisher 400 eye tube

    thing is I am not sure if the MPX circuit I have goes with the schematic for the rest of the receiver. Anyway I still have to sweep the fixed IF and just to make sure its peaking at 10.7 (I have in tuned there but not sure if that happens to be the peak as I peaked the entire IF chain and not...
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    fisher 400 eye tube

    I checked it WAS R206 (found it in the early series fisher 400). on the schematic for this one it says DELETED for R206 well, i lifted that leg on that resistor (the one that was deleted on some models) and the tuning behaves just like the other fisher (fully closes on MPX with a good signal)...
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    fisher 400 eye tube

    the saga continues, after fixing the Z2 if and aligning everything including the MPX i was perplexed by the amount of opening the eye tube does when the MPX is engaged. I have a good mono indication, and I get a good lock with mpx but on my 3 if tube fisher the mpx simply closes the eye more...
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    fisher IF can micro surgery

    here it is with the 33pf caps in http://www.youtube.com/watch?v=nMyVRJPbapE
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    fisher IF can micro surgery

    Dave, the caps on that one were made from a mica sheet that was retained by the rivit, a spring steel plate and a plastic piece under the sprint steel (seen popping loose late in the video). Its coming along, I need to try the 30pf as I assume the Q of the transformer may be off some, more to come.
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    fisher IF can micro surgery

    video posted http://www.youtube.com/watch?v=WrjAk4g39f4&edit=vd
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    fisher IF can micro surgery

    well I kind of answered my own question, at least on the top. After noting the location of the slug, which was pretty near the top of the can (2.75 turns from the top to be exact) I adj all the way down until it lightly bottomed out, never got a peak again. My guess is the IF were designed to...
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    fisher IF can micro surgery

    Dave, my IF use the flat blade adj, they have big ferrite cores that thread on the outer plastic shell (when I get the video up it will be obvious). Do you know if they have enough adj for a peak on each coil? If so do you know if the peak should be set for core close or cores apart or core both...
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    fisher IF can micro surgery

    while working one my second fisher I was having a lot problems getting a good solid lock on the MPX. I tried the fisher described approach, no luck, then sweep gen checking each stage with a demodulator prob. The 1st IF can after the tuner (Z2) would drop out intermittently while trying to adj...
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    quick question fisher 400 IF can

    after messing with it I am sure the Z4 is opposite of the directions, the Top is part of the overall IF, the bottom is the secondary that adj the Eye tube. I hope someone can confirm this for me.
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    quick question fisher 400 IF can

    Z4 the primary is the bottom? top is for the indicator correct? this is for the 4 IF tube models. I am doing the alignment per the instructions (non modulated IF signal, vtvm at tp3 and chassis), and the eye tube is acting funny. after tweeking the IFs (top and bottom z1-z3 bottom only on z4)...
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    why 80khz not 67khz on mpx

    Here is another fisher with a MPX problem I will be looking into soon. http://www.youtube.com/watch?v=3nn418NcBEc&feature=youtu.be I have a feeling its going to be in the ratio detector, since that is after the takeoff point for the FM mono indicator.
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    why 80khz not 67khz on mpx

    Thanks! I am looking forward to my other one, it was even worse for sensitivity. I got it off ebay, I am just guessing here, but I am pretty sure it was fiddled around with before I got it (screw driver drift).
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    why 80khz not 67khz on mpx

    http://www.youtube.com/watch?v=zbP7Xop26WM&feature=youtu.be video of the completed fisher 400
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    why 80khz not 67khz on mpx

    Done, you were right, I grounded out the MPX 74v, then noticed I still had an antenna wire attached (I just had tuned away from a station) with the ant off AND tuned to a dead spot I again got the 74v. Its working great now, with just a short wire (jumper lead) I get a lot of stations with...
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    why 80khz not 67khz on mpx

    couple more things to note, the 165v supply (confirmed voltage at filter cap) shows a drop across a 220k plate load resistor down to 75v with NO SIGNAL at least according to the fisher mpx notes. I have about 155 v at that plate (V100), but with a signal I get about 95v, not 75v but a lot...
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    why 80khz not 67khz on mpx

    Thanks for all the help Dave, I think I am almost there, I have confirmed the peak using the mono FM eye on a weak station. I just want to check on more thing, the secondary of the ratio detector, think I will sweep and use a scope for the S curve AND use a VTVM for a zero volt ouput a the...
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    why 80khz not 67khz on mpx

    tsp 101 scope stereo RF modulator no signal low band (90khz) peak up Z100 top and bottom for max pilot amplitude peak bottom ratio detector (primary) peak all IF back to tuner peak tuner coils (all but osc) repeat High band (108khz) peak tuner trimmer caps (all but osc) by...
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    why 80khz not 67khz on mpx

    stereo, in the mono mode the tuning eye opens a max of about 1/2 on strong stations, switch to stereo and it closes up nearly all the way but modulates to the audio programming. I used a scope to setup the ratio detector (primary and S curve on secondary), but when trying to align the rest of...
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