Batboard

is it possible to build a talk through repeater using two radios that will pass Astro. eg 2 motorola Gm300

I too was wondering the same....
I think I asked similar question with this posting some time before.
I have not yet tried using a repeater such as the one you listed, to see if it works.



John

Please let me know if you are sucessful in doing this...



http://batboard.batlabs.com/viewtopic.php?t=6012

I am not totally sure, however, I think I've read that you can by running the repeater in CSQ.

-Josh

John:

Do you have a VHF Astro capable radio?

This topic has been around a couple of times, and I'm curious about the answer Some people say it will work CSQ, some say it won't work because Astro modulation is four level FSK and won't pass through a conventional repeater.

Off the cuff, I'd have to go with the skeptics, but if you have a VHF Astro radio, I'll throw on of my GR1225s at work into CSQ some day, and we can give it a shot.

I'm certain that you could pass audio through something like two Astro Sepctras and a controller, taking the audio to analog in between, however, you would only repeat the audio, not the digital signaling data.

HumHead..

I do have a VHF Astro.

PM, we can set something up...and advise of our findings


John

I'm one of the skeptics. My bets are on that it won't work. The 4-level FSK being the reason.
It potentially "could" work by using an ASTRO radio to turn the ASTRO data back to audio, then take that audio and send it out on the transmit radio. It could work but the problem would be very distorted audio. The audio would be run through the vocoder twice and the distortion would be very high.
I would be interested to hear how it sounds.
-Caff

We had one of Will's extender modules at Dayton. It was connected between a UHF maxtrac and a VHF maxtrac in a X-band configuration. It would mass MDC1200 like a charm, but wouldn't pass Astro properly. After that, we tried to crossband with a Kenwood TMD700A with no success. After we reported our findings to Will, he said he was going to go back and look at it more. Maybe if he 's reading this, he can provide us with a little more info.

-Bob

It should be able to do anything, as long as the audio is sent flat, without pre or de-emphais, from the reciever to the transmitter. No mic inputs need apply .

Maybe tie it into the deviation pot, right off the discriminator? Gripe, but it would probably load down the discriminator too much.

I dunno.

Bob wrote:We had one of Will's extender modules at Dayton. It was connected between a UHF maxtrac and a VHF maxtrac in a X-band configuration. It would mass MDC1200 like a charm, but wouldn't pass Astro properly.

-Bob

Of course it won't pass ASTRO! MDC1200 is audio tones Frequency Modulated (hence "FM") onto a carrier. ASTRO is a 4 level FSK. FSK is different from FM as is AM, SSB, BPSK, etc, etc...
Caff

APCO 25 will not pass through a non-digital repeater like it would a analog machine. Myself and several of my buddies take our XTS's and Astro's and try to do it all the time, but it won't work. If you can get a signal into the machine, it won't carry the digital data packets. You will just hear noise. Sorry. Wish Quantars were a bit less expensive.
JS

Thanks for the replies to my post. I have had discussions with a friend involved with Paging transmitters (FSK) and paket radio (FSK) years ago and he thinks it is possible to do.So ill keep looking.

The Motorola Micor, and Mitrek will do exactly that. You need to modify the radios for this. The radio needs to be able to pass DC. In other words if a radio capable of DPL the radio can be capable of digital operation. This will take a few minor modifications. The varactor needs to be able to swing a good 5k plus audio. I have built several portable digital repeaters and they all seem to work fine, but keep in mind that in order for you to have both an analog and digital capable repeater much more ill be needed. For just a digital capable "passthru" repeater it will take you a 3-8 hours depending on your technical expertise.

The GM300, Maxtrac, 1225 etc are not capable unless you do some major mods, not worth the time for the end result. And not to mention a couple of spectras are capable of this as well.

Speaking of which.

Some local hams here are looking at seeing if it's possible to set up a 2 meter (VHF) repeater that can be used in both analog (with older radios) and digital.

The repeater being used right now is a Motorola MSR something or other.

It was donated by a near-by Police Service that went from VHF to 800MHz not too long ago. It's in mint condition, so I'm guessing it's new.

Yes, I KNOW it's illegal to use digital on ham radio, but, we're concerned with it it will WORK or not, not if it's LEGAL.

Thanks!


Mike

Good luck on the project.
I didn't think it would work until I saw USGOVTECH's post about modifing the radio to pass DC. I guess that hard part would be getting the transmitter to give the proper frequency shift to corresponding DC level from the receiver. Then it would have to be able to keep up with the 4800 bps symbol rate. HHmm..not impossible...but I see why it takes 3 to 8 hours to align.

I don't know about Canada, but it's not illeagal to transmit P-25 digital on the ham bands in the US. /\/\ has a P-25 ham repeater in Shaumburg on 2M and crossbanded to the 220 MHz ham band.
-Caff

I tried it on our sheriff posse rptr which I have been putting together for a few months at my house and it wouldn't work. With the rptr In CSQ mode I tried flat audio, every combination that I could set the rptr up in and still nothing intelligible.

I think if the rptr is set up as an IF type of system where the Receiver IF is sent into the transmitter, prior to the rx demodulator stage that it may work, of course then I would need to do some serious carving up and adding stages (IE mixing the rx IF to a LO to get the rptr output frequency) to the rptr transmitter section which I'm sure the Local sheriff wouldn't let me do so now I'm thinking of getting some conventional Maxtracs or something else and making an IF style rptr just for my own experimenting to see if I can get it to work.


Mike

Digital illegal in Canada? Say it isn't so?

What's so illegal about digital? Packet is digital and it's on VHF.

Looks like NorthYork20 is confusing digital with encryption. Digital does not equal encryption. Got it? Good.

Industry Canada has no problem with digital. Just don't encrypt and you won't have any problems.

As far as a repeater that can support both digital and analog it's pretty simple. Quantars come to mind and possibly the MTR2000. Have the locals with digital program up their receive with mixed mode. Anybody breaking in using analog will be heard. The digitals can switch over to analog (if they so wish).

I called the local IC office the other day, they told me that any digital audio of ANY kind (even non-encrypted) is illegal.

That sorta goes against the "reason" for Ham radio, but...there you go.

Maybe HE thought I meant encrypted, even though I said NOT.


Mike

r0f wrote:Do what I did..

Get a commercial license and use the digital radio on the frequency you are assigned. Screw the hams in that regard.. I know I've tried to get things going up here with hi-tech stuff, but nobody's interested.

I gave up on amateur about 5 years ago.

Shaun

OK.. you have your own commercial license... but who can you talk to? Yourself?

That doesn't seem very fun to only be able to talk to yourself. If you wanted to talk to yourself, you could use the SUPER ENCRYPTED internal communication pathes in your brain. And you wouldn't need a license, nor expensive radios.

Did I miss something?

Isn't the point of radios to communicate with other people?

OK I can keep my mouth shut no longer: Jonathan, for CHRISTS SAKE QUIT BEING A SMARTASS. NOBODY CARES ABOUT YOUR OPINION! That was a pretty RUDE statement you just made if you stop and think about it. Your the only one I know on this board who's got some off-the-wall comment that is purely OPINION and has nothing to do with intellectual gain for the benefit of all. If you like, I'll suggest they have a JONATHANS OPINIONS forum for you to post all of your nonsense in. THINK before you POST.

(sorry guys I couldn't keep it down any longer)

~119~

d119 wrote:

KC8RYW wrote:OK.. you have your own commercial license... but who can you talk to? Yourself?

That doesn't seem very fun to only be able to talk to yourself. If you wanted to talk to yourself, you could use the SUPER ENCRYPTED internal communication pathes in your brain. And you wouldn't need a license, nor expensive radios.

Did I miss something?

Isn't the point of radios to communicate with other people?

OK I can keep my mouth shut no longer: Jonathan, for CHRISTS SAKE QUIT BEING A SMARTASS. NOBODY CARES ABOUT YOUR OPINION! That was a pretty RUDE statement you just made if you stop and think about it. Your the only one I know on this board who's got some off-the-wall comment that is purely OPINION and has nothing to do with intellectual gain for the benefit of all. If you like, I'll suggest they have a JONATHANS OPINIONS forum for you to post all of your nonsense in. THINK before you POST.

(sorry guys I couldn't keep it down any longer)

~119~

I'll try to explain myself again; perhaps I miscommunicated something.

I am just curious as to whom r0f communicates with on his own commercial license.

In my previous reply, I was explaining that the point of telecommunication (such as two-way radio) is to communicate with another human being.

If a commercial license is had for one's self, then who does one communicate with using that license?

Perhaps maybe Shaun just didn't give enough information in his post. Maybe he runs a business of his own, and uses his commercial license for that. Maybe he talks to his friends using his commercial license. Or maybe he just likes talking to himself over the radio, using his commercial license, like I presumed in my prior reply. Who am I to say? Who am I to speculate? It really doesn't affect me one bit. I was just curious to know. It seems like a ligit question to ask, all things considered.

Remember, this was a QUESTION I was asking, not an opinion. Using assumptions, I began to try to answer my own questions. Assumptions are not opinions.

I didn't think this was very difficult to understand. I'm sure that one can understand what I am trying to communicate in this and my prior post with a little logical thinking.

The irony of it all is that d119 assumes that I want to hear about his opinion. However, I truely do appreiciate your opinion, d119.

If anyone has any quarls with my postings in the future, please PM or email me. I'm sure the average board user has better things to do with their time then to read through a personal attack against myself.

Thank You.

Jonathon et all..

I believe Shaun uses his commercial 2-way license for a security business, if memory serves me correctly.


Mike

Please play nice, i'd rather not lock the topic.

-Alex

HAH!