Newbie Question

[VK-SWL002]

Hi all,

New to HAM as a hobby. Long time user of UHF, VHF marine, and military comms. Looking to broaden my interest in radio. With the dying of my Uniden UHF radio in my 4x4 I am looking at purchasing an Icom ID-5100A for mobile comms. Ordered my copy of the foundation manual from WIA.

At home I am playing with SDR at the moment. Any users here of SDR? Don't really seem to have any success listening to anything other than FM radio.

I have a NooElec R820T2 SDR mated to a Diamond D-130 discone antenna.

Any pointers on where to go to learn?

[VK4ADC]

Darren

Visit http://www.gcars.com.au/ for info on the Gold Coast Society details - you may find someone there who can provide the guidance you need regarding FL assessment etc.

Re SDRs, try http://www.ozlogger.net/forum/viewforum.php?f=14 as there are at least a few posts there, starting with my initial post.

Can't tell you anything about the Icom ID-5100A for mobile comms. Maybe someone else can. (!!!!!!!!!)

Doug VK4ADC

[VK-SWL002]

I'm good with the licencing part thanks mate. Waiting for my manual to arrive and Ill contact gcars once it arrives.

I spoke to a dealer about the ID-5100A. They say it doesnt work across the Australian UHF and VHF Marine frequencies. They said its restricted from that range by Australian law. Bit disappointing, seemed a pretty good price and the videos I have watched of it in use suggest it's highly capable.

I really don't want to fit a new UHF radio and an amateur radio in my 4x4 due to space constraints, would prefer one radio.

[VK4ADC]

I'm good with the licencing part thanks mate. Waiting for my manual to arrive and Ill contact gcars once it arrives.

I spoke to a dealer about the ID-5100A. They say it doesnt work across the Australian UHF and VHF Marine frequencies. They said its restricted from that range by Australian law. Bit disappointing, seemed a pretty good price and the videos I have watched of it in use suggest it's highly capable.

I really don't want to fit a new UHF radio and an amateur radio in my 4x4 due to space constraints, would prefer one radio.

The issue with one radio for UHF CB and amateur radio is the the equipment for CB cannot be modified in any way eg so that it will cover amateur frequencies - and even if it was capable of covering both bands, it would then be illegal. In a different way, amateur equipment is not approved for UHF CB or marine use - different technical specs and different testing regimes. In reality, the three services can't use the same equipment.

The best option - as a fallback - for radios in the 4X4 is what I have done in mine - both the Uniden UHF CB and the Icom HF/VHF/UHF radios have remote heads which are mounted in the dashboard area while the radio body is under the front seats. Not great but it works for me.

Doug VK4ADC

[VK-SWL002]

Im trying to get rid of the Uniden UHF. Its pretty poor, receive range is less than 3km though the transmit is somewhat longer. I have a 1 watt handheld UHF that gets 5km easily, my 5 watt vehicle radio is next to useless. In a vehicle convoy the Uniden wont RX/TX to vehicles I can see around me. Its been back to the dealer twice and they say there is nothing wrong with either the radio or the antenna.

Ive never been a fan of UHF, always used VHF or HF in the military. I always thought our VHF radios were bad but UHF is like using two cans on a piece of string.

When I was at an outdoor show at the Gold Coast Turf Club last year I was talking with a guy from a amateur radio network about HF. Whilst chatting he showed his setup. One radio was his HF but the other was a VHF/UHF combo. He was monitoring two channels at the same time and was able to switch between them. Whilst we were talking we were listening to vehicles as well as Southport Coast Guard.

[VK4ADC]

Im trying to get rid of the Uniden UHF. Its pretty poor, receive range is less than 3km though the transmit is somewhat longer. I have a 1 watt handheld UHF that gets 5km easily, my 5 watt vehicle radio is next to useless. In a vehicle convoy the Uniden wont RX/TX to vehicles I can see around me. Its been back to the dealer twice and they say there is nothing wrong with either the radio or the antenna.

Ive never been a fan of UHF, always used VHF or HF in the military. I always thought our VHF radios were bad but UHF is like using two cans on a piece of string.

When I was at an outdoor show at the Gold Coast Turf Club last year I was talking with a guy from a amateur radio network about HF. Whilst chatting he showed his setup. One radio was his HF but the other was a VHF/UHF combo. He was monitoring two channels at the same time and was able to switch between them. Whilst we were talking we were listening to vehicles as well as Southport Coast Guard.

While it may seem strange to ask, what type of antenna are you using on the 4X4 ? Model number ?
Different antennas have different lobe angles and high gain antennas designed for accessing repeaters on high hills/mountains may have a high lobe angle while you actually need a more horizontal lobe angle for reasonable distance vehicle-vehicle comms. These are generally have a lower published gain figure and are a straight (or variant of a) quarter wavelength whip.

There is nothing to stop you putting VHF marine frequencies or UHF CB frequencies into an amateur transceiver if the receiver will cover those frequencies but it can only be used on receive for them. The amateur equipment can't be used to transmit on those frequencies as it isn't Type Approved for the other services - in fact, it generally isn't Type Approved at all.

UHF is even more line-of-sight than VHF hence the more obvious distance limitation. VHF has always been described as extended line-of-sight and handles obstructions such as trees, foliage, small hills etc better as there is less signal attenuation from those at VHF than at UHF.

Hope that helps..

Doug VK4ADC

[VK3RX]

my 5 watt vehicle radio is next to useless. In a vehicle convoy the Uniden wont RX/TX to vehicles I can see around me.

Odd.

The radio isn't set to DUP (duplex i.e. repeater) mode by any chance? That should be set to off when not using a repeater.

What model number is the radio?

[VK-SWL002]

The antenna is a GME AE4705. I have to two antenna for the base, a 3dbi and a 6.5dbi. I use the 3dbi around town and the 6.5dbi whilst out of town.

Added in 2 hours 45 minutes 39 seconds:

my 5 watt vehicle radio is next to useless. In a vehicle convoy the Uniden wont RX/TX to vehicles I can see around me.

Odd.

The radio isn't set to DUP (duplex i.e. repeater) mode by any chance? That should be set to off when not using a repeater.

What model number is the radio?

Ill get back to you tonight. I need to pull out the control unit as its installed beneath my centre console.

[VK-SWL002]

my 5 watt vehicle radio is next to useless. In a vehicle convoy the Uniden wont RX/TX to vehicles I can see around me.

Odd.

The radio isn't set to DUP (duplex i.e. repeater) mode by any chance? That should be set to off when not using a repeater.

What model number is the radio?

The radio is a Uniden UH7760NB.

It is set to Duplex, it cannot be turned off. Channels 01-08 and 41-48 I can select "n1". In the Menu when I try to change it from Duplex on any other channel it shows "Er" and remains on Duplex.

[VK3RX]

OK I'm not familiar with that model, so what I say I'm only going on what is in the manual I've found online.

I have to think the fact you can't talk to other vehicles in convoy would be due to the radio not being set correctly i.e. its set for repeater (duplex) mode instead of that mode being off.

Page 17 "Operating the UHF CB Radio in Duplex Mode" details how to set channels to repeater on or off. As it says, "Only channels 01 - 08 and 41 - 48 are available for Duplex." That is, it can't be set to duplex on any other channels.

As you have a separate radio (handheld), you can test things are working simplex by selecting (say) channel 19 on both and doing a test transmission.

Some people operate simplex (i.e. repeater off) on repeater channels and their reverse channels when they think they aren't within range of a repeater, instead of using any of the other (simplex) channels, and maybe that's what's happening to you. For this type of operation, you would set the particular channel to "OFF" using the page 17 procedure.

If you still get stuck you could either try a reset of the radio (which might happen if you follow the procedure in the youtube video below) in case there has been a glitch that has messed up the programming of the radio, or alternatively drive to the dealer so they can see the whole installation (radio and antenna connected) and show them what is happening.

https://www.youtube.com/watch?v=-j_hD1RjqGo

[VK-SWL002]

Ok. That video shows unlocking the radio from 40 channels to 80 channels. I did that quite awhile ago.

When I go onto a channel other than 1-8 and 41-48 I can see that they are set to duplex however when I try to toggle them I get "Er". On 1-8 and 41-48 when I try to toggle duplex I get "n1". "n1" is only offered as an option on 1-8 and 41-48. I am thinking that "n1" means duplex is on and "Er" means duplex cannot be selected. For the reason that "Er" only shows on the non-repeaters channels.

[VK4ADC]

Ok. That video shows unlocking the radio from 40 channels to 80 channels. I did that quite awhile ago.

When I go onto a channel other than 1-8 and 41-48 I can see that they are set to duplex however when I try to toggle them I get "Er". On 1-8 and 41-48 when I try to toggle duplex I get "n1". "n1" is only offered as an option on 1-8 and 41-48. I am thinking that "n1" means duplex is on and "Er" means duplex cannot be selected. For the reason that "Er" only shows on the non-repeaters channels.

Maybe it is time to re-lock it back to 40 channels and see if you still have the duplex issue on channels 9 through 30. You haven't mentioned which channel number you have tried/been using when in convoy and maybe something in the order of 10 through 29 should be the desired value.

The Er will undoubtedly mean error so, yes, it is not a selectable option in the 80 channel state. Even more reason to revert.
The N1 would/should probably mean negative offset duplex is active for 1-8 etc.

73 Doug VK4ADC

[VK-SWL002]

I'll have to contact Uniden about reverting from 80 channels. There doesn't appear to be anything on their website about going back from 80 to 40.

I dropped into the dealer today where I bought the radio from. The extent of testing was to unscrew the antenna and try another. The radio worked across the car park fine but we couldn't hear any radio traffic when scanning. They could test the cable as they don't have an SWR meter. They offered to fit another antenna though I would have to buy it. Told them I am not going to buy a new antenna unless I know that the antenna or its cable are at fault.