[Hammarlund] SP-600 tracking align

[Richard Knoppow]

    Please clarify what you did. There is a section on IF 
alignment on p.16 of several of the instruction manuals. It 
requires the use of a signal generator coupled to the grid of V5, 
using a socket adaptor. The same set up is used for both IF 
frequencies. 455 is aligned first than 3.955. There are three 
adjustments for the 3.955 IF. Once you have tuned this you can do 
the RF oscillator. You can measure the 3.500 Khz crystal by 
removing the shield and wrapping a wire around the tube. You can 
then pick up the output on another receiver. That will show if 
its at the right frequency.
    To get on the wrong side of the 3.955 IF the local oscillator 
would have to be nearly 9 Khz off. The second IF is run from a 
crystal oscillator, normally below the first IF frequency. It 
can't be tuned so can't run on the wrong side of the first IF.
    So, what is going on here?

On 11/12/2019 2:56 PM, wb3fau55 at neo.rr.com wrote:
> Guys thanks for your input. The 3..50 2nd osc was peaked on the wrong
> side as suggested. This fixed the 7 to 14 mc tracking. Little
> improvement on 15 to 30mc. was 1 mc too wide, now 850kc.
> 
> 	Maybe 3.5mc xtal is too aged and too far off freq? Test that next.
> 
> 	Worked on 6 of these 600s. i find super radio. Tracking can be dead
> on if time taken to do the adjustment.
> 
> 	Someone told me these are poor RX about 15mc. Wrong- all a matter of
> recapping and alignment.
> 
> 	Add a digital display and it is way cool. Radio seems to be an early
> JX-1. Parts inside show a 1951 build. Even hears 6m beacon signals.
> Too bad there was never a SP-800. Russ.
> ______________________________________________________________
> Hammarlund mailing list
> Home: http://mailman.qth.net/mailman/listinfo/hammarlund
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Hammarlund at mailman.qth.net
> 
> List Administrator: Gary Harmon, K5JWK
> ** For Assistance: gharmon at idworld.net **
> 
> 
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> 

-- 
Richard Knoppow
1oldlens1 at ix.netcom.com
WB6KBL