[Hammarlund] SP-600JX14 problem FOUND Vol-II - capacitor shaft NOT BENT

[Richard Knoppow]

    Thanks for letting me know. I have no idea what might have happened 
but it turned out OK. The dial of the SP-600 ia absolutely the smoothest 
I have ever found.
    I will mention again checking the frequency of the second conversion 
oscillator. I have encountered sets where the single conversion bands 
are exactly accurate, within the thickness of the pointer, but the 
double conversion frequencies are slightly off with the end points set 
correctly. I think this is due to an error in the second conversion 
oscillator frequency. Easy enough to check.  There are a couple of 
variations on the IFO, in the JX-17, the diversity version, there is a 
capacitor across Y-7 but in the standard version there is none. I am 
sort of guessing the crystal can be trimmed to frequency.

On 11/21/2024 4:32 PM, Bill Cotter wrote:
> After a total teardown of the SP600JX14 gear train, I discovered the 
> gear was NOT bent. What was wrong was that the two ball bearings (one on 
> each of the gear) were missing! What caused it to appear bent in the 
> photographs was the spring action of the tuning capacitor link to the gear.
> 
> I measured the ball-cup and determined that the proper size was 0.187" 
> or 3/16" dia. I bought a 600-ball assortment from amazon for $8, and 
> used two oof them to repair the gear train. While it was all apart I 
> cleaned every part and lightly lubricated the shafts and sliders, and 
> left the brass gears dry. It is unbelievably smooth.
> 
> Thanks to all the posters with their help.
> 
> 73 Bill N4LG

-- 
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998