Two Radios / One Control Head

[rileym]

Looking to share a head between A4 Astro Spectras between 800 and VHF.

Wondering if anyone has found an easy way to install a "switch", possibly using a pc parallel port splitter, something to avoid having to actually unplug the head cable in order to use the other band...

[thebigphish]

It is possible to configure two Astro Spectra's to work from a single, hand-held, control head. The information we have received so far is that it requires the following parts:

YLN1138A - ASTRO SIU BOX
YLN1142A - ASTRO SIU AND SOFTWARE
6807994D15 - SIU RSS MANUAL

Sounds a little more technical than just a parallel port splitter. I can't imagine the radio decks would like having their logic lines just opened with a flick of a switch, my guess is they'd drop out as soon as you switched it...

[jmr061]

Its a dream that won't come true.

Options are to go with A3 dual astro spectra setup mentioned above (yes its a A3 not W3 head), XTL5000 dual radio setup with single W3 or do the APX7500 mobile.

Jason

[Johnny Grep]

Or dual M7100IP setup, if you're willing to use M/A-COM.

[mr.syntrx]

Tait's TM8260 dual radio setup is quite sexy, if you don't need P25.

[rileym]

Thank you for all the replies.

In that case, I will be best served by using a HHCH for one, and regular for the other, and can then use either, and swap cables to radios if need be.

[Jim202]

Thank you for all the replies.

In that case, I will be best served by using a HHCH for one, and regular for the other, and can then use either, and swap cables to radios if need be.

You might want to look into the Kenwood radios. They have a few trunk mount radios that will do dual radios with a single control head.

Jim

[rileym]

Thanks for the tip, but I need type II trunking in 800.

[metro121]

I have not been on this forum for a long time, and this post realy caught my eye.

I was making special order control units which would allow you to operate up to 4 spectras with one control head.

I have since moved to Arizona and have not done much with radio's but I will look for my notes on the design I came up with.

I am sure I have it somewhere. If I do find it , I will try and locate all the parts I need to build them and maybe sell a few here on the forum. I was selling them for $350.00 each back in 1998.

metro121

[mr.syntrx]

That's pretty cool.

Did you ever try it with ASTRO Spectras?

[TWEMARS]

I have 4 conventional Spectras working off of one head in my Suburban. I did this by installing a 4-way 25 pin switch in the line from the control head to the radios. It, obviously only does one radio at a time but I only need to use one radio at a time.

TRY THIS FOR AN A-5 OR A-7:

Power each radio from pin 4 in the rear plug. This is on the SWITCHED side of the on-off switch. I THINK that you can switch between one of two radios and the other radio should (might) stay up. If that doesn't work, get a 25 pin cross switch and try it again with a dummy head stashed somewhere out of sight. Remember, the heads are dumb. All the info comes from the radio.

I'd be curious to know if this works. Contact me at sandysamuels (AT) aol (dot) com.

[desperado]

to keep the radios up you would need to modify the control head interface board.
The head routes power back down the cable and tells the radio to power up. If you switched the head to a different radio the radio would power down.

The other big issue would be the control head updating its display. The head would loose power as it was switched so it would also cause the radio to reset.
the busy lines would also cause confusion is a 4 position switch configuration.

I will say this, it CAN"T be done with a 9 series head, as it's smart and contains the channel information.
Part of the advanced firmware is the command set that see's the head swap and holds the radio in place and doesn't change the radio status of cause a reset.
My guess is that you would get one radio to work and the other 3 would fail on power up and as soon as you switched to another radio the first radio would get an 01/90 error. All in all, I would say that you either do it with the correct Motorola parts or don't do it at all.

Another option is this. The mw800 or mw810 had a software package on it that was called vRCH or virtural Remote Control Head. It ran on a computer and interfaced to the radios via a mini-RIB. It would send basic commands to the radio (which required a control head to be connected) and would change volume, channel and zone. It had a bit more functionality than that, but not alot. You still needed a mike for each radio but the heads could be stowed or mounted under the MDT (laptop dock) and never touched unless the MDT was non functional.

A third option is an NCS-250 patch box. I put one of these in a fire chiefs vehicle with 4 radios, 3 were trunked. It took installing some time delay boxes to get the audio to all come through because of the trunking talk permit tone delay, but it's a functional solution. It uses a select and unselect speaker and a single mike. It works like a dispatch console giving the user the ability to patch two or more radios together, talk on multiple channels and/or talk groups at the same time and even patch the receive audio over to the external siren PA system if one desires. Google NSC-250 for the skinny on it. It's not a cure all, but if you are wanting to clean up an install, add functionality to it to boot, couple the vRCH with the NCS-250 and all the other radio grreks will crown you king of the hill and want one too.