Minitor II - Alignment after re-crystal

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RESCUE161
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Minitor II - Alignment after re-crystal

Post by RESCUE161 »

I just bought a Minitor II that is set for 154.3700. I need it to be on 154.3100, so I bought the appropriate crystal. I can solder the crystal with no problems. My question deals with the alignment of the pager after I change the crystal.

I have the following test equipment:
Fluke 6060B RF Signal Generator
Simpson analog meter
Digital multimeter
O-Scope
Spectrum analyzer
Frequency counter

Can I do an alignment on this pager with what I have, or am I going to have to buy more test equipment? I ordered a service manual off of Ebay. I couldn't find a PDF of one anywhere.
Scott
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yankeeradio
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Re: Minitor II - Alignment after re-crystal

Post by yankeeradio »

Changing the freq crystal that close to the existing freq, alignment NOT needed.
k2hz
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Re: Minitor II - Alignment after re-crystal

Post by k2hz »

A full alignment should not be needed if it was working properly on the old frequency but you may need to adjust the crystal frequency. It should at least be checked with a frequency counter.

Crystals from some vendors can be quite far off to the point you will have decode and distorted audio problems if you don't adjust it.
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RESCUE161
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Re: Minitor II - Alignment after re-crystal

Post by RESCUE161 »

When I got the crystal, I installed it and then used the Fluke Signal Generator to align the pager. It only needed a tiny bit of tweaking and it works way better than the Minitor III that I have here. It alerts every time and the audio is crystal clear. The Minitor III is scratchy and doesn't alert some times.
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irishlad
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Re: Minitor II - Alignment after re-crystal

Post by irishlad »

What is the maximum chance recommended before alignment is required?
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Re: Minitor II - Alignment after re-crystal

Post by kd5wfy »

Thanks for the replies. The pagers I got were down in the ham band and I am wanting to bring them back to 154.37
irishlad
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Re: Minitor II - Alignment after re-crystal

Post by irishlad »

I have a few Keynote pagers on 155.820 that need to be changed. What is the maximum movement away from that frequency that I can have before needing to re-align it?

Thanks
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