This unit is a testament to Zenith's pulling out all the stops to make a better radio
than even Nordmende and other makers of early 60's table treasures.
I had one for years, then I found another one on the "free table" at a swap meet.
All original tubes tested strong and free of shorts. well...it sort of played but crackles, so it was there for a good reason (if there is such a thing)
and here it is...
H845a.JPGH845b.JPGH845c.JPG
I cannot believe Zenith would use these damn things in those big, impressive IF cans, but they do
. This radio has no less than seven of these, so how do you know which one is the bad guy?
The problem was isolated to one can, the first AM IF can affected both bands;
#1- Grounded the grid of the second IF tube, silence, then grounded the grid of the first IF tube, silence again. This placed the trouble in the cans BEFORE even the 1st IF stage. Next, I used a modified chopstick to prod the terminals on the bottom of the suspect cans and the crackles stopped, so I powered down, loosened the big nut in the bottom of the can, plugged in and VOILA...clear AM signal came through! and FM came back also
As can be seen of the L8 A4-A5 can in the schemo, the caps are not labeled as to the value.
I can't replace them all, so I will do this one and see how it goes.
Does anyone know the value of these capacitors?
