Batboard

I am preparing to install several Astro Specta 800 radios pre-programmed for the San Diego City TRS, and the SD County RCS 800 trunking systems. The problem I have is that these radios auto affiliate all over the place! I wish to install these radios in a vehicle equipped with a single 800 antenna, utilizing an 800 MHz multi-coupler. The auto affiliation per the multi-coupler manufacturer, will damage the device. They tell me they can "safe" the multi-coupler against a handheld radios affiliation burst, but say that the 12 watt burst would probable be too powerful for their modifications.

So I am stuck with a few options, plug everything in and see if my 3 Uniden scanners start smoking and explode, or install more antennas. To install as few antennas as possible, would two Astro Spectras sharing the same antenna be able to handle each others affiliation bursts when T'd out on one antenna lead? I think that since the TX will simply travel through the other Astros TX capable circuits, that they won't hurt each other. I already have an Astro that does not affiliate, and I am hoping I can turn it off, but if not, will the two radios/one antenna option work? Can the Astro Spectra be programmed to transmit at a very low power setting, compatible with the multi-coupler makers "hardening" for handheld TX power?

Paul

What is the limiting factor here? Is it the power rating for the coupler? Since affiliation burst are pretty short, unless the issue is breakdown voltage, I wouldn't think power would be an issue - there's not going to be a great deal of heating from those bursts, but there could be too much RF voltage to break down the insulators.

Is this a monitor only set up or will the radios be used for transmit also?

There is a fix for this, but you have to sacrifice power-on-ignition capability and being able to turn scan on and off.

1.) Remove the control head and locate JU1 and JU2.
First pic is for a W5/W7 head, second is for a W4. You're out of luck if the radio is W9 or W3.




2.) JU1 should be blank and JU2 should be installed. Swap them around.

3.) Under CPS-->Radio Wide-->Advanced, set Ignition Switch to"TX Inhibit."

4.) Enable Auto-Scan on all of your trunked personalities.

5.) Congratulations, you now have no-affiliate scan. This works on rebanded and mixed-mode Smartnet and Smartzone systems, but not Astro25 9600. If the ignition sense line sees 12V at any time it will attempt affiliation.

JH, yes, these are monitor only radios.........I have a bunch of older Spectras, Astros and Maxtrac radios that I physically opened up, and CUT the transmit wires, so they could not transmit.

Paul

If they're not going to transmit EVER then check the "Multi-Radio System" checkbox and set the radios as the auxillary radio. They will throw an error on power-up but that will clear and they will not transmit at all, no affiliations, nothing.

.....but wil the radios still RX on a Smartzone system without a delay or problem?

The radios will never ever transmit for the rest of their existance. They will basically be scanners until they are totally obsolete and tossed into a dumpster.

Paul

Anderegg wrote:.....but wil the radios still RX on a Smartzone system without a delay or problem?

Yes, using either of the above-described methods. You can even program a button for Site Display/Search and force it to hop sites.

Again, this is only applicable to Smartnet/Smartzone. Astro25 9600 will still attempt affiliation, and Astro25 firmware in an Astro Spectra kills HRR functionality.

...and you never replied to the similar issues you were having over at RR.com

The SD systems have an auto inhibit on it, and obvisiouly you either generated or received the system key or your using someone's radio ID - unless the city/county issued you your own radio ID's for news media.

First suggestion is don't do it as they WILL brick the radios automatically. They even have their own talkgroup which plays a prerecorded message stating the same.

In any case, you may need to rethink your entire setup and way of monitoring...and the people here are very good at this unlike radioreference. You may want to post your radio reception requirements - and transmission requirements if any.

pj, the radios in question were programmed personally by "Bob", the SD Sheriff's RCS codeplug guru. They have unique radio ID's, and can be killed or shut off if you don't pay your bill or they decide they don't want you to listen in any more.

I am going to see if Bob can remove the auto affiliation feature.......if not, I am left with two options.

1: Install a new NMO mount, and splitter for both Astro's to operate off one antenna

2: Drill two new holes and run each radio separately

I prefer option 1, I just don't know if the auto affiliation burst will fry the opposite Astro on the line? Will they be safe, can they handle each others bursts?

Paul

SmartZone requires affliation. That is built into the software and is required to properly have the system track the where talkgroups need to talk to which sites based on needs.

In any case, just enable the HHR option and you don't need to worry about the radios transmitting if it has a 1MB board. If its a 512k radio it still may attempt to transmit (it will xmit for sure on a conv channel -for a 512k radio)

Thanks Pj, the radios all have the 1MEG sticker on them.

HHR?

Paul

HRR. Look for it in the help file and check off the option when located.

OK, I just confirmed the auto affiliation is REQUIRED by the RCS, and that it would be ill advised to "mess with" their programming in that respect.

So my choice still remains. Drill one hole in my roof and use a T splitter to feed BOTH radios, or drill two holes and feed each radio it's own antenna. I would prefer not to turn my vehicle into a porcupine, and would really like to confirm whether or not if the Astro's transmitting their affiliation burst would not harm each other.....I mean, the circuitry that transmits will be the same circuitry that will take the burst right? I could just test this out, but if I am wrong, I would fry at least one of the radios.

Paul

Your still dropping 15-35 watts into a radio..

Anderegg wrote:.I mean, the circuitry that transmits will be the same circuitry that will take the burst right? I could just test this out, but if I am wrong, I would fry at least one of the radios.

Paul

No. The radios have circuits to switch the antenna port between the transmitter and receiver - they don't do full duplex. So the radio sending the affiliation will know to switch to the transmitter, but any other radios on the same antenna will not know, and will leave their nice 0.2uV sensitive receivers on the line to get the 5V TX burst - can you say *POP*?

Then it's settled.......I must drill more holes.

Paul

Anderegg wrote:Then it's settled.......I must drill more holes.

Paul

The 'other' antenna in the rear inside deck...
Under the car...

As a curb feeler !!!!!