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How to set 10.7 MHz marker on ST 1000A

jblmar

jblmar

JBL & marantz
Hello,
I've been looking at YouTube regarding FM alignment. Very helpful videos. They make mention of the 10.7 MHz Marker.
I have the Sound Technology ST 1000A FM Generator. How do I get to see the marker on the o'scope?
 
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What tuner are you trying to align? Different tuners need different procedures/equipment. A IF 10.7MHz sweeper is usually needed to align the "IF filters" if it is using tuned ckts.
Rick
 
Just trying to learn what I saw on YouTube. They lift one side of a cap and inject a 1KHz signal. My Marantz 2130 tuner has .05% distortion, I calibrated my ST 1000A to
.035% which is too close to the 2130. I can use the ST 1701A instead. It has .0015& distortion @ 1KHZ, The 2130 manual doesn't mention injecting a signal.
I don't intend to touch anything on the 2130 at the moment, just to check it. If I understand correctly, this method is used as follows;
Set the 1000A to output RF of 10.7 MHz (I have the Fluke 1900A Frequency Counter. Very accurate).
Connect the RF out to antenna in on the 2130
Inject the 1KHz signal as above
I should be able to see the 'S' curve and marker.
Is this correct?
I'll buy some inexpensive FM radios with the manual to get the feel for alignments.
 
Hi jblmar (Ron), You need a 10.7 "chirper". I have one. It's a little device, this one made by Sound Technology, that superimposes a mark when aligning using ST's dual-sweep alignment procedure.

It allows you to center the IF tuning. The only thing is, a 10.7 marker doesn't really need to be used as most tuner IF sections use fixed SAW (Surface Acoustic Wave) filters. Where a 10.7 marker would come in handy is on something like a 10B, where the IF filters are tuneable.
 
Rick, Thanks for your input.

Hi Jon,
You're right the 2130 uses SAW filters. Where can I get the 'chirper' to align FM Tuners that need it?
Thanks again.
 
Hmmmmmmmmm....


maybe check on e-bay from the usual supects like: Meguro, Leader, Panasonic, Marconi, Boonton, Sound Technology.

I'll dig mine out and see if I can come up with a schematic. I think the toughest part would be to source the XTAL of 10.7000000000MHz. Probably custom sourced.
 
jblmar said:
Hello,
I've been looking at YouTube regarding FM alignment. Very helpful videos. They make mention of the 10.7 MHz Marker.
I have the Sound Technology ST 1000A FM Generator. How do I get to see the marker on the o'scope?
Click to expand...

The 1000A IF alignment uses a method called "dual sweep" that eliminates the 10.7MHz marker alignment. Do you have the 1000A manual? Dual sweep allows you to see the IF bandwidth and set the "flatness" of the central portion, a quality required for low distortion. Where the 1000A may not be the best choice for IF alignment is the stagger tuned IFs used by many McIntosh tuners and the Marantz 10B. Stagger tuning is a sneaky method of boosting selectivity.
IIRC the "CW" position outputs 10.7MHz through the RF allowing you to directly inject it into IF sections.
 
Thanks, Nakdoc,
I did use the 1000A a few years ago to see the scope display with the 2130. It was as described in the 'dual sweep' section. I plan to use the 1000A with my 2130, if it ever develops a problem, but I would like to learn how to align other tuners as well. Been viewing YouTube, but all the videos inject the signal marker or don't use the 1000A. As you can see, I know nothing about FM alignment.:sigh:
 
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