The Siren Board

Can I Unsolder the Crystal and Put one with the Proper Frequency in a Siratrol Radio Controller? How do I change the tone that activates it?

I am Looking to Buy a Thunderbolt 1003 and all the Controls (Siren, Blower, Motor Starter, AF Timer, Siratrol Radio)

soundman56 wrote:Can I Unsolder the Crystal and Put one with the Proper Frequency in a Siratrol Radio Controller? How do I change the tone that activates it?

I am Looking to Buy a Thunderbolt 1003 and all the Controls (Siren, Blower, Motor Starter, AF Timer, Siratrol Radio)

If you have the proper skills and tooling to do so, yes you can swap out the crystal filters to the proper frequency you require. The hard part is sourcing the appropriate crystals for the desired frequency as they are pretty hard to come across. Check with any local radio shops in your area to see if they happen to have what you need, especially older shops since they may be more likely to have some laying around from older equipment.

Thanks murrfarms! I'm pretty good with a soldering iron. Do you know how I can change the tones the controller responds to?

Try looking here: http://www.gcomradio.com/reeds.html

Thanks eows1212man!

Whoa whoa whoa, slow down!!

First, how far a change in radio frequency do you need to do? If it's more than a few 10's of khz, you'll need to align the receiver section for best sensitivity. Assuming you have alignment instructions and a proper, calibrated signal generator and such to do it.

Maybe from 1 channel to another, say 25 KHz or so away, you've probably be able to just swap crystals, but much more, and you'll be tearing your hair out. I used to do the old Motorola Minitor & Pageboy pagers, back over 27 years ago. It's a snap with the right tools & knowledge.

so I cant just put in new crystals and new tone reed filters?

Tone filters, most likely can. How big a difference in RF frequency?

I don't know how old the 'Siratrol' controller is, but the older the receiver unit is, the more likely that it would have come in different 'band-splits' that were pretty narrow; maybe only 2, 3, or 4 mhz wide. (say 146 to 150, 150 to 154, 154 to 158, etc. ) Meaning, if you changed frequency within that range, a 'simple' tuning would suffice. If you went across a range boundary, you were either screwed, or you would have to change other frequency sensitive components like coils & capacitors.

The manual is your friend.

The tone filters, being audio, most likely will be OK. I've only ever seen a couple designs of audio decoder circuitry that required changing more than just the filters. YMMV.

thanks kb4mdz

soundman -

Do you have, or have access to, the manual for the receiver for this controller? If you don't and you have no experience tuning receivers, you might be in deep pucky.

How far exactly are you wanting to change frequencies?