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Hello Fisher sapiens. why would my signal meter indicate normal 4 out of 5 on reception but only drop to 3 off tuning or without signal?. Thanks

Hi Fans: The following experiment is an attempt to observe objectively the effect of releasing Dave"s noose mod on a Fisher 500C Material: Restored Fisher 500C, All new balanced Tungsol 12ax7 s New matched quad of 7951A Tumg-sol. Noose mod on only one channel (left) , mod as...

Hi fans; Is there a good use (application ) for a HP 3561A Dynamic Signal Analyzer in a tube lab ? Thanks Vintelectra

Hi Fans: I got myself a HP 3561 dynamic signal analyzer for my tube lab work, this complex instrument. Is there help out there to connect it for the following applications: 1) display the entire audio frequency response of an amp 2) display THD 3) calculate IMD 4) other. any help is welcome...

What would be the functional result of replacing the 500c transa for both 400 trannies? Thank you in advance. Martin

Hi Fisher-aficionados! What is the functional feasibility or result of replacing both 500-c output trnnys for Fisher 400 transf? Thanks Martin

Hi Fans: Why would a tube push-pull amp distort lows and attenuate highs when matching resistive load is applied, as opposed to beautiful sound without load? (heard on earphones), thanks Vintelectra

Hi Fans; My problem is: Stereo Beacon light ON at off-station in 500C receiver . Did the following: changed neww 6gk5 for another new. Checked beacon circuit and relay. changed new IF strip tubes, and shielded,Oscillation stops when pulling 6hr6. Oscillation causes ( as expected) neg grid at...

Hi tube Fans: Can someone tell us the causes of a low audio channel separation in a integrated push-pull tube stereo amp with phase inverters and integrated pre amp??? Would appreciate thanks Martin

Hi fisheraficionados: Could someone tell us the reasons /causes of poor audio separation?? In this particular case I am getting 15 dB from left to right, and 29 dB from the right to left, sampling from 1st grids of Phase inverters. Thank you. Martin

Hi Fisher experts:Restored Fisher 500-c with the following problem: very low output Right phase inverter V13 vs left V14). Signal discrepancy traced to grid 2nd triodes: 0.1 vrms on right (weak channel) vs 1.7 vrms on good left channel,however, input (grid of 1st triodes ) have 0.28v on v13...

Hi Fisher Sapiens: My good working Fisher 500-c, has a spurious sound when switching off. I read and enjoyed David Gillepsy"s article on audioxpress. I this the switch off pulse he describes? If so, why I do not get in in other 500-c? Would screen resistors alleviate the finding? Thankfull as...

Hi Fisher sapiens:I noticed that the phase inverter tubes V12 & V13 have a ceramic disc cap 5npo between grid (#7)and contra-lateral cathode (#3). This is not depicted in the schematics I have. Two questions: a) what is the function of them, and b)are they considered to be an audio path cap...

Hi Fans : working on a Fisher 500-c , I find a ceramic cap of 5npo between pin 7(grid) and pin 3 (contra-lateral cathode) on each inverter tube V12 &V13, but not present in the schematic I have. Two questions : whats the function of these, and could they be considered within the audio path...

Hi Fisher Fans:Just finished a restoration on a 500-c and I find a poor frequency response in the audio output, which did not happen before with same set up: New Mullard 12ax7 and new j/j matched, grid resistors mod done, Munsford 0.1 uf coupling caps, good output pwr. When measuring freq...

Hi fans : My 500-c , just restored shows early clipping and distortion when vol ctrl is at mid range. I traced the early clipping to the second triode of both driver 12ax7(new). any Ideas?? thanks in advance.

My Fisher 500-c audio stage is clipping at mid range, any Ideas?

Hi Fisher Fans: I am finished restoration fisher 500-c, excellent sound and no noise when signal is tuned, but very strong white noise when off tuning or antenna removed. Special attention was given to the limiter, with v.r checks and good response to aligment of tranformer. When V2 is...

Hi Fisher aficionados. I am restoring a Fisher 500-c limiter IF autotransformer, can not find replacement. Need to know value capacitance of the two inbuilt caps at the base. Many thanks in advance. Martin

Hi Fisher Fans: I am restoring a If limiter coil of a fisher 500-c( could not get a replacement) Anybody knows the values of the base (in-built) capacitors for these? Thanks in advance Martin

Hi Fans: Restoring this fisher 500-c MPX decoder if find that there is no separation. New tubes, recapped mylars, changed diode bridges and nothing. Need help ! Tanks in advance, martin