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View Full Version : OT - Uniden PRS Tranceiver UH-040XR



somebody
26-07-2003, 11:23 AM
I've been thinking about getting a number of these to use as a wireless comm system for concerts etc. What I'm wondering, is if I have an always-on headset mic, will that stop me from being able to listen to others talk?

Graham L
26-07-2003, 03:59 PM
Just a guess: yes. :D They will transmit/receive on the same channel. It's a PRS "personal radio service", aka CB. Just because it's UHF doesn't mean it's ultra high technology.

somebody
26-07-2003, 04:12 PM
I have read that it can be put into "Duplex" mode, but i'm not too sure what that means.

somebody
26-07-2003, 09:18 PM
Is anybody who has experience in this area able to help me?

Bazza
26-07-2003, 10:48 PM
Hi Somebody: If what you have read is true, then maybe it could work for you.. as far as I know Duplex means transmitting both ways, i.e like on a telephone, when both parties can speak/hear at the same time, as opposed to "simplex" where only one party can speak/transmit at a time.

promethius
26-07-2003, 10:52 PM
I thought simplex was only one way transmission?

Bazza
26-07-2003, 10:57 PM
Right on Promethius, that is what I said..Only one party can speak/transmit at a A time..

Bazza
26-07-2003, 11:13 PM
So now Promethius, what say ? about duplex v simplex ?

I am not familiar with the Uniden tranceiver that the poster asked, but I do have experience with HF, VHF, & UHF transceivers, and as far as I know the facts of duplex & simplex are as stated

Will you comment, or maybe some other PF1ers could comment.

grb67
26-07-2003, 11:17 PM
If you want n always on headset you need the 042 which has VOX for voice operated. Not successful in high noise areas, you are better with push to talk. The duplex refers to 2 frequencies and is used with a wide area repeater. Try channels 1 thru 5 on duplex to see if there are repeaters in your area.

Bazza
26-07-2003, 11:43 PM
We are still waiting Promethius ? Can you please explain your comment about "simplex" that differs from mine ?

Curly
27-07-2003, 08:21 AM
Well, I read the question as "If anyone is standing near me while I am wearing a headset, will I be able to hear them".

If I am not off course- yes if you have a headset which has only one earpiece. :-))

somebody
27-07-2003, 11:07 AM
I may not have worded the question too well. I was referring to hearing people through the PRS Tranceiver, and not people next to me.

somebody
27-07-2003, 11:15 AM
Thanks for all your suggestions everyone. I will continue investigating.

The reason I ask is all PTT headsets which are available specifically designed for the UH-040XR are exceedingly expensive (from DSE website), and the design of which would not be suitable in the environment I wish to use it in. I was planning that if I did invest in a set of these, I would use standard computer-headsets (about $20 each), and just get adaptors so there are suitable size plugs to fit into the unit.

I would be willing to go with a PTT headset if there were any available cheap enough (under $30 each), and of decent quality.

Tobas
27-07-2003, 11:43 AM
Well yes of course they will hear you, afterall that is the purpose of the setup. You speak into the microphone and they hear you in their headset, and viceversa. :-)

Pheonix
27-07-2003, 01:12 PM
FYI Simplex is where you transmit and receive on the same frequency. Duplex is where your transmit and receive frequencies are different.
Simplex is used to communicate directly between transceivers.
Duplex is normally used to communicate with a base station repeater. This is usually placed in a high position, so giving greater coverage. Different frequencies enable the transmit and receive to be on at the same time. If it was Simplex, repeater would receive from transceiver, start transmitting from repeater, which would get up it's own receiver....ad infinitum.

somebody
27-07-2003, 03:47 PM
So does that mean that I can't use a Duplex mode on one of these, and be able to talk and listen through it at the same time?

Graham L
27-07-2003, 03:48 PM
I have had a look at the DSE catalogue, and from the description of some of the other models I have come to this conclusion:

DUPLEX in this particular context (ONLY) means: capable of having the receive an transmit frequencies offset by 750 kHz, to enable the use of the set with a repeater.

You can do what you want if you install a repeater. :D

It might be easier to use a PTT headset. If you look for "UH-040XR" in google, you will find a link to someone who has implememented a PTT function ( for data transmission). (Aparrently Uniden don't give out the required circuit information --- they sell an expensive headset :D).

somebody
27-07-2003, 05:39 PM
Thanks Graham.

I think I know which site you're talking about - I found one with extensive photos of the inside circuitry etc. for a guy who was connecting it to some kind of data transmission thing.

Now I have to re-find it:D

godfather
27-07-2003, 07:34 PM
> DUPLEX in this particular context (ONLY) means:
> capable of having the receive an transmit frequencies
> offset by 750 kHz, to enable the use of the set with
> a repeater.
>
> You can do what you want if you install a repeater.

I would disagree, in that the unit will be unlikely to recieve and transmit (albeit on different frequencies) at the same time.
The "front end" will be highly unlikely to have sufficient filtering to exclude the adjacent transmit channel, on such a low cost item.

Receive OR Transmit. Not both at the same time. Duplex in this manner simply means receiving and transmitting are on different frequencies, not both at once however.

If you are transmitting you are not receiving. And vice versa.

So even a repeater is unlikely to help.

Billy T
27-07-2003, 08:24 PM
I concur with Godfather's advice. You cannot transmit and receive at the same time. I use two Uniden tranceivers with duplex facility and it is definitely for use with repeaters.

Of course, you can do what you want with two cellphones, but although the capital cost can be very low, the talk time is very expensive.

No free lunches here unfortunately.

Cheers

Billy 8-{)

somebody
28-07-2003, 11:04 PM
What alternatives would I have? Would getting cheap walkie-talkies from The Warehouse or some kind of children's toy store, and wiring headsets into them work?

godfather
28-07-2003, 11:12 PM
If you want true duplex (i.e. you have a continuously live mic yet hear the other party, just like a phone) then cheap unfortunately doesn't work.

You need to look at professional gear, where the tx and rx frequencies are on different bands, not just different channels. Think $thousands, not $hundreds perhaps.

Cordless phones get the closest, and some 900 MHz DECT ones may allow handset to handset (intercom) use, and accept headsets. Again a very expensive solution.

JaceKiwi
09-06-2007, 09:31 PM
If the 'phones work without the base unit then that may be the way to go

JaceKiwi
09-06-2007, 09:32 PM
What power rating/max distance are these?

somebody
09-06-2007, 09:54 PM
JaceKiwi - I asked this question about 4 years ago, and fortunately I found ways around the problem (several times actually).

In the end, I ended up hiring a combination of fixed-wire comms (http://www.beltpack.com/), and a custom-built unit which interfaced this fixed system with a series of (hired) PRS radios with PTT headsets. While it wasn't perfect, it worked well enough for the event I was managing.

Though I didn't test it myself, I believe the (wireless part of) the system had a range of around 1km line of sight, depending on the receiver - as the guy we hired it from said he could listen in to our communications on his van-mounted unit while driving around town.

BobM
09-06-2007, 10:53 PM
I've been thinking about getting a number of these to use as a wireless comm system for concerts etc. What I'm wondering, is if I have an always-on headset mic, will that stop me from being able to listen to others talk?

Check out NZ Scanners group. They would have good info on this gear.