Help needed with Instalert receiver

[dmitry103]

Hello,

I’ve searched the forums and haven’t been able to find much information with regard to Instalert receivers. This is an older model, see attached photo for reference. Receiver frequency must be old 46.10 and I’m looking to tune it to 155.55 instead. Any help and/or guidance would be appreciated. I can post pictures of the board, if necessary. Thank you.
Dmitry.

 

[a417]

Hello,

I’ve searched the forums and haven’t been able to find much information with regard to Instalert receivers. This is an older model, see attached photo for reference. Receiver frequency must be old 46.10 and I’m looking to tune it to 155.55 instead. Any help and/or guidance would be appreciated. I can post pictures of the board, if necessary. Thank you.
Dmitry.View attachment 82083

That is a very old model, and I highly doubt you will be able to move it from low band to VHF- Hi band. I'd be willing to bet that it's crystal controlled and is designed only to work on low band, but it's been MANY years since I've been under the hood of one of those. If you were trying to do an in-band move, say 46.10 to 45.04 - then i'd say you'd probably only be a crystal change and some slight tuning away, but this is a quantum leap for that unit. If you want to post a pic for nostalgia, I wouldn't complain.

If it was something like this then you would be able to do a fair bit of changing of the frequency, as this is a synthesized unit that is basically an older bearcat (it was bearcat, wasn't it?) scanner and a tone decoder board. It was many years ago, but I think you had to pop the head from a bearcat scanner on it and you could change the frequency to almost whatever you needed. [edit - within the capabilities of the reciever, all of low band, VHF, or UHF depending on the set]

Good luck!

 

[dmitry103]

Thank you for reply and your insight, I attached a photo of what's under the hood. One of the stations I work at has the exact model currently in service. It's been “upgraded” from original low band to match the current dispatch frequency. Such a unique piece of history.

 

[buddrousa]

Those were sold in Bands like PAGERS you bought the band you need.
LOW BAND 40Mhz to 50Mhz ect
High Band 150Mhz to 160Mhz ect
UHF Band 460Mhz to 470Mhz (If these were made at all)

 

[a417]

I know of several counties in the commonwealth that bought Federal Signal Informers when they rebuilt their paging systems, that or the Instalert model I posted are viable replacements. The Federal Signal Informer also has relays outputs to simplify building services activations (call lights, bay lights, etc) upon reciept of a valid tone set. IIRC the model you will be looking for (VHF Hi band w/ IO ports for relays) is the Federal Signal I-HIOW or I-HIO . (the W was for wall mount if you absolutely NEEDED it, but i've seen more than enough desk mounts put on walls or shelves)

 

[trap5858]

As others have noted, it is unlikely that a change of that magnitude could be performed and then at what cost? I had a Plectron receiver that alerted on 46.10 back in the day and considering where you want to be I am betting on Bucks County! Good luck with your project.

 

[IC-R20]

Frequency change is easy if you really want to use this radio. Just get the appropriate downconverter for it. Easy job for a receive only radio. I have a transverter on my HF rig so I can do 2m SSB/AM ops. Lotta useless LIDs in here lately.

 

[a417]

Frequency change is easy if you really want to use this radio. Just get the appropriate downconverter for it. Easy job for a receive only radio. I have a transverter on my HF rig so I can do 2m SSB/AM ops. Lotta useless LIDs in here lately.

Thanks. I have never seen a downconverter used in mission critical public safety alerting systems. It can be ok for ham ops, but it's just another moving piece when the appropriate hardware is more readily available.

It would be a very short argument in court when something happens and someone says "why did you hack this together and do so and so when you could have modernized and hardened the installation?".

The juvenile name calling is cute.