Digital to analog converter?

PhillyPhoto · Post by **PhillyPhoto** » Tue May 03, 2005 9:11 am

Has anyone every seen anything that will convert an APCO-25 signal to analog? It would probably have to go in-line with antenna. Thanks

tvsjr · Post by **tvsjr** » Tue May 03, 2005 2:07 pm

In-line with the antenna? Err, no.

http://www.aorusa.com/ard25.html

Interfaces to the 10.7MHz IF output of most of your better communications receivers (Icom R7000/7100/8500/9000, etc.)

MotoTech · Post by **MotoTech** » Tue May 03, 2005 2:36 pm

NO!
By yourself a digital scanner or radio!

tvsjr · Post by **tvsjr** » Tue May 03, 2005 10:14 pm

MotoTech wrote:NO!
By yourself a digital scanner or radio!

Whoa, take some valium, dude. The AOR box is exactly what he's looking for, a convertor. Now, he may not be able to get 10.7 out of his radio, but if he can, it'll work great.

PhillyPhoto · Post by **PhillyPhoto** » Wed May 04, 2005 7:17 am

Anyone know how to make a 10.7 output? LOL, oh well just wondering. Thanks

Post by **Wowbagger** » Wed May 04, 2005 8:11 am

The AOR unit is somewhat interesting, but I wonder why they chose to process the 10.7MHz IF rather than just processing the analog baseband from the radio's detector.

Given that you have FM discriminator output, recovering the C4FM data from that is child's play, vs. processing the 10.7MHz IF and recovering the signal.

And most of the radios I've seen that had 10.7 out had discriminator out as well.

Heck, even if you DON'T have disc out - recovering the signal from C-weighted audio wouldn't be too bad. I wouldn't advise trying to do signal parametrics on it - don't try to compute modulation fidelity, but for just getting a bitstream...

Of course, if you *want* parametrics....

MattSR · Post by **MattSR** » Wed May 04, 2005 9:33 pm

AOR unit can be configured to use a discriminator tap as well.

PhillyPhoto · Post by **PhillyPhoto** » Wed May 04, 2005 9:56 pm

Would it be posible to use one on a analog-only mobile radio like a CDM or MCS maybe even a analog spectra? (I know astro spectra would be easier, but humor me) This is why I'm looking for something that would go in-line with the antenna. I have never done anything with the discriminator on my 780, so I'm not too familiar with it.

mr.syntrx · Post by **mr.syntrx** » Wed May 04, 2005 10:08 pm

It would be far from being a trivial procedure.

MattSR · Post by **MattSR** » Thu May 05, 2005 1:29 am

I know of a bloke in Sydney that modified his Tait 2020 to work with the AOR... was quite a simple procedure actually...

mr.syntrx · Post by **mr.syntrx** » Thu May 05, 2005 2:37 am

I was thinking of getting the thing to transmit and receive.. my bad.

willbartlett · Post by **willbartlett** » Thu May 05, 2005 5:43 am

Anyone know how much the thing is. (google laziness, sorry) And if it can be configured for disc. tap, a spectra shouldn't be too difficult.

Will

firemedic4 · Post by **firemedic4** » Thu May 05, 2005 12:37 pm

Thanks luie for starting this topic. i got my boss to order two of the units were going to try them on an mcs and spectra...

radio-link · Post by **radio-link** » Sat May 07, 2005 11:45 pm

LuiePL wrote:Would it be posible to use one on a analog-only mobile radio like a CDM or MCS maybe even a analog spectra? (I know astro spectra would be easier, but humor me) This is why I'm looking for something that would go in-line with the antenna. I have never done anything with the discriminator on my 780, so I'm not too familiar with it.

Think about it once again - how should a device in-line with the antenna know what frequency you want to listen in? Of course it would possible, then this device would consist of a complete apco25 receiver and an analogue transmitter - so why bother retransmitting the stuff again, instead of connecting a speaker to this receiver? You get the point? :)

PhillyPhoto · Post by **PhillyPhoto** » Sun May 08, 2005 6:36 am

Yeah I understand, but I figured it might be easier to get for the antenna, than messing around with the discriminator. On something like a scanner it wouldn't really be for tranmitting anyway.

radio-link · Post by **radio-link** » Sun May 08, 2005 7:10 am

LuiePL wrote:Yeah I understand, but I figured it might be easier to get for the antenna, than messing around with the discriminator. On something like a scanner it wouldn't really be for tranmitting anyway.

No, technically it is just not possible. To convert some kind of digital signal ins some kind of analog signal you must completely decode it, and this means you completely "receive" it, so no need for another receiver=scanner behind it, just a speaker. And also it is not possible to convert a whole range (for example, 160-174 MHz) into another mode, like from digital to analog, and then tune the station at the scanner. To decode a APCO25 signal you have to tune in exactly on the frequency you want to listen to.

PhillyPhoto · Post by **PhillyPhoto** » Mon May 09, 2005 10:25 pm

Alright, that makes enough sense. I guess we'll have to wait and see how firemedic4's project goes to see if it can be used on /\/\ radio's

Astro Spectra · Post by **Astro Spectra** » Tue May 10, 2005 4:53 pm

Might pay to review:

http://batboard.batlabs.com/viewtopic.p ... highlight=

Digital to analog converter?

Digital to analog converter?

converter

Re: converter