Hello,
I've been viewing YouTube videos re FM Tuner Alignment. I'm not sure how to set and view the 10.7 MHz marker on the scope using the Sound Technology ST 1000A. Can anyone explain?
Thanks.
I've been viewing YouTube videos re FM Tuner Alignment. I'm not sure how to set and view the 10.7 MHz marker on the scope using the Sound Technology ST 1000A. Can anyone explain?
Thanks.
Only suggestion I have is to get a manual. Usually the scope is used in X-Y mode and the markers show up as pips on the displayed curve.
Thank you, DIck.
I have the ST 1000A manual. It only covers Dual Sweep, no mention of injecting a signal.
On YouTube, they show The 'S' curve, sweep and frequency injected to create the marker. I'm missing something.
Is it possible that the Dual Sweep function makes the sweep and marker unnecessary?
P.S. A few years ago I tried the Dual Sweep method outlined in the ST 1000A manual and my Marantz 2130 looked perfect. I would like to learn the method shown on YouTube for aligning other tuners.
I have the ST 1000A manual. It only covers Dual Sweep, no mention of injecting a signal.
On YouTube, they show The 'S' curve, sweep and frequency injected to create the marker. I'm missing something.
Is it possible that the Dual Sweep function makes the sweep and marker unnecessary?
P.S. A few years ago I tried the Dual Sweep method outlined in the ST 1000A manual and my Marantz 2130 looked perfect. I would like to learn the method shown on YouTube for aligning other tuners.
Last edited:
I last used an ST1000A around 1980, in another life, so my memory is dim. I don't ever remember injecting 10.7MHz into the IF strip of a solid-state tuner -- just went through the RF input. I did this with McIntosh and Marantz and every other kind back then, because it was by far the easiest and most accurate.
But it is possible to inject the IF -- details will vary depending on the exact design of the IF stage. In the good old days of vacuum tubes, you could just connect the swept IF signal output to an ungrounded tube shield and drop it over the first IF stage tube, and voila -- signal at the detector.
See if the manual says anything about injecting IF. You could make sure the tuner is not tuned to a station, and use a small cap (1000pF?) to inject the 1000A IF sweep into the emitter of the first IF stage -- if you can actually get at it -- or perhaps into the mixer stage somewhere -- equally hard to access.
Sorry I can't be of more help.
But it is possible to inject the IF -- details will vary depending on the exact design of the IF stage. In the good old days of vacuum tubes, you could just connect the swept IF signal output to an ungrounded tube shield and drop it over the first IF stage tube, and voila -- signal at the detector.
See if the manual says anything about injecting IF. You could make sure the tuner is not tuned to a station, and use a small cap (1000pF?) to inject the 1000A IF sweep into the emitter of the first IF stage -- if you can actually get at it -- or perhaps into the mixer stage somewhere -- equally hard to access.
Sorry I can't be of more help.
Sound Technology sold a "Frequency Converter with 10.7 MHz Marker" as an accessory to the 1000A FM Alignment generator.
I found the following statements on the internet..... "It has one BNC input connector marked "90 MHZ IN". The output BNC is marked "10.7 MHZ OUT".
It has two switches, one marked "Converter On", the other "Marker On". An internal 9 volt battery is the power source."
".....you don't get a directly calibrated and useful attenuator on the signal using one of these. But that being said, this is really all you would need, since the usefulness was in just testing the IF section for go- no go."
I found the following statements on the internet..... "It has one BNC input connector marked "90 MHZ IN". The output BNC is marked "10.7 MHZ OUT".
It has two switches, one marked "Converter On", the other "Marker On". An internal 9 volt battery is the power source."
".....you don't get a directly calibrated and useful attenuator on the signal using one of these. But that being said, this is really all you would need, since the usefulness was in just testing the IF section for go- no go."
You need a good frequency counter to make use of the ST1000. Its a remarkably good generator and when fully adjusted very linear. Setting the modulation meter is quite challenging, needing a very good spectrum analyzer. Once set it should hold quite well. Verfying the linearity of the modulator is also very challenging.
Most IF's you will encounter are ceramic filters and have no adjustments. The ones with double tuned transformers will need alignment and there things get complicated. The ST1000 is adequate to the task. You do not need to drive the IF directly. The oscillator in it is quite low distortion and an analyzer on the tuner output will confirm you have things pretty optimum.
You would need a network analyzer if you need to set up something like a Marantz 10B.
Most IF's you will encounter are ceramic filters and have no adjustments. The ones with double tuned transformers will need alignment and there things get complicated. The ST1000 is adequate to the task. You do not need to drive the IF directly. The oscillator in it is quite low distortion and an analyzer on the tuner output will confirm you have things pretty optimum.
You would need a network analyzer if you need to set up something like a Marantz 10B.
