HAM Radio (Amateur Radio)

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Gyxx
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Re: HAM Radio (Amateur Radio)

Postby Gyxx » Mon Oct 14, 2013 12:14 am

Right you are 26 MHz for NZ...

Not that I have the CB on very often these days. It's been so long since I've had an AM contact that whenever I do put it on I just leave it on 11 and catch the odd truck coming down the Haywards or on SH2.

Like so many I cut my teeth on AM CB and then moved onto SSB rigs before getting my Ham ticket. I hope we don't lose the HF CB band it's still quite a handy wee band in it's own right.

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MikeL200
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Re: HAM Radio (Amateur Radio)

Postby MikeL200 » Mon Oct 14, 2013 11:05 am

These bands do get monitored for usage and if there isn't much or any activity some little beauracrat will be looking to sell off the rights to use them. Sadly technology and the internet will cause this to happen. Why go the harder way when IRLP, All-Star or Echo-link means you can talk to the world from your vehicle or on a handheld?
Mike
1989 LandCruiser MWD BJ74 13BT
33 Deserthawk XMT.


[color=#FF4000]If guns kill people, then,
Spoons make people fat,
Pencils mis-spell words,
and Cars make people drive drunk.


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DieselBoy
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Re: HAM Radio (Amateur Radio)

Postby DieselBoy » Mon Oct 14, 2013 11:57 am

Gyxx wrote:Right you are 26 MHz for NZ...

Not that I have the CB on very often these days. It's been so long since I've had an AM contact that whenever I do put it on I just leave it on 11 and catch the odd truck coming down the Haywards or on SH2.

Like so many I cut my teeth on AM CB and then moved onto SSB rigs before getting my Ham ticket. I hope we don't lose the HF CB band it's still quite a handy wee band in it's own right.


The little group of us that go cruising regularly all run CB's, the range beats the PRS hands down. People are missing out just using the PRS. We can chat from Taupo to just about Turangi on the CB.

I feel the urge to get my license building :lol: :lol:
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tgaguy1
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Re: HAM Radio (Amateur Radio)

Postby tgaguy1 » Mon Oct 14, 2013 4:42 pm

I have a question for those that run an AM CB.
When I have my AM CB radio on (with aerial mounted on front bullbar) and I use my Garmin Nuvi GPS; the GPS has trouble staying locked onto satellites. When I turn the radio off, the GPS has no problem staying locked on.
Has anyone else come across this and if so, is it a function of aerial location or will the AM signal interfere regardless?
I find UHF radio has no interference at all with the GPS.

Cheers

Jase.
Men do not quit playing because they get old.
They grow old because they quit playing.

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MikeL200
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Re: HAM Radio (Amateur Radio)

Postby MikeL200 » Mon Oct 14, 2013 5:20 pm

I have my AM CB mounted on the dash and I have a Garmin Nuvi 760. My aerial is on the drivers-side front guard and I have never had any problems like yours. My LED lightbar however kicks up a shitload of interference with the CB. The frequency difference between CB and GPS is way too big to be a problem, 27mhz v 1250 mhz.
Mike
1989 LandCruiser MWD BJ74 13BT
33 Deserthawk XMT.


[color=#FF4000]If guns kill people, then,
Spoons make people fat,
Pencils mis-spell words,
and Cars make people drive drunk.


021 666812

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Gyxx
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Re: HAM Radio (Amateur Radio)

Postby Gyxx » Mon Oct 14, 2013 10:20 pm

A little bit of loose RF (especially HF) can find it's way into the most unlikely places and do the most unusual things. It finds every little bit of inductance or capacitance it can and pops up where you least expect it.
When I was saying about making the neons at the servo flicker before I was only half joking. Apparently when my old antenna was pointed a certain way my neighbors TV would get interference bars that would modulate in sympathy to my RF power output on SSB...
That would make sense if your problem only occurred when you're transmitting. If it's happening when you set's only receiving - buggered if I know...
In the absence of any definitive fault, I've always found going through all the connections (supply, earth, RF etc...) and making sure they're all fully sound has a magic way of making problems disappear. An earth for the chassis of the transceiver sometimes works wonders too...
LED lights are notorious for causing RFI. Some of the less well-made brands can splatter most of a band for a little way. A lot of boaties are fitting LED light strips then finding they're having to take them back out or move them or suppress the RFI from them somehow because they screwing up their communication with all their splatter...
I'm still a big fan of HF CB. On a good day and using legal power I've worked some surprisingly distant stations - funny speaking people and all ;-) ... You can't do that with UHF.
OK Yeah I know these days you can do it all on IRLP but... I'm old school... I still have to wait for the valves to warm up before I can transmit and I like the soft yellow glow they put out when they finally do... My frequency stability takes a good five minutes to settle down... Good time to make a cuppa...And check the E-mail on the Android ;-) .

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UBZ
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Re: HAM Radio (Amateur Radio)

Postby UBZ » Tue Oct 15, 2013 8:38 am

tgaguy1 wrote:I have a question for those that run an AM CB.
When I have my AM CB radio on (with aerial mounted on front bullbar) and I use my Garmin Nuvi GPS; the GPS has trouble staying locked onto satellites. When I turn the radio off, the GPS has no problem staying locked on.
Has anyone else come across this and if so, is it a function of aerial location or will the AM signal interfere regardless?
I find UHF radio has no interference at all with the GPS.

Cheers

Jase.


Firstly are you using an external antenna for the GPS?
the inbuilt antennas have the their gain cranked right up, to make up for the fact that the antenna is not that good . therefore making them very susceptible to being washed out by "any" RFI.

Secondly - The AM transceiver needs to be wired properly . It should have a Negative power connection direct to the battery and to the body . The battery should be connected to the body and the chassis as well.
Run the antenna coax feed line as far away as possible from ignition wiring / alternators etc . Cut the feed line as short as possible ( fixed length feed-lines for mobile applications are a 4wd Myth) don't bunch up excess in the engine bay or behind the dash .
make sure you use quality RG58/U cable and connectors .

Thirdly - The Antenna .... a bullbar is probably the worst place you can mount an antenna , as it is separated from the main body of the vechile RF wise .
The antenna base should have an electrical negative , ideally direct back to the battery .
Just because a the antenna has a negative connection does not mean that it has a good RF ground
A 5cm metal disc under the base will help simulate a ground plane on the bullbar but needs to be connected to the body of the vechile with a good wide (1-2cm) braided copper ground strap . the body of the vechile also need a ground strap to the chassis .
The more RF continuous your vechile is the better the "RF Ground" will be. this can be done by using ground straps on the bonnet , doors , exhaust , basically any major item that is bolted to the vechile. All connections should be sanded back to bare metal and a electrical jointing compound used .

Basically if the Antenna does not have a good "RF" ground it will reflect a large portion of transmitted power back down the Coax cable to the radio . This results in poor radio performance , in-cab interference and can potentially damage the radio .

The proper way to check is with a VSWR meter . this will let you see how much power is being reflected and the VSWR ratio .

On a side note , alot of "pre-tuned" antennas are not actually tuned that well or are affected by mounting location . using a VSWR meter you can lengthen/shorten the antenna to tune it properly .

there is ton of info on the Net about Mobile Antenna tuning / grounding / bonding , if you are prepared to wade .

DieselBoy wrote:I feel the urge to get my license building :lol: :lol:


Do it !
I found out the other day I can arrange for the test when ever you feel you are ready for it ..... no need to wait for a club run course .
LR110 ..... LJ50 project :roll:
Chris.

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tgaguy1
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Re: HAM Radio (Amateur Radio)

Postby tgaguy1 » Tue Oct 15, 2013 5:02 pm

Thanks for the replies. I will have to check all connections and modify the wiring a little I think. My have to re-think ariel placement as well. Some very good knowledge on this forum.

Thanks.
Men do not quit playing because they get old.
They grow old because they quit playing.

Flip
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Re: HAM Radio (Amateur Radio)

Postby Flip » Wed Jan 01, 2014 2:31 pm

I mostly use a simple Wouxun UVD-1P dual band hand held with a 6db dual band external automotive antenna in my landrover. I find it works well enough in most places. I keep thinking about a dual band base set but the hand held is cheap, works on the PRS frequencies and just does 99% of anything I have ever asked it to do. If I flood the truck I have only buggered a $100 hand held, also I have not found a base set that will do VHF,UHF and PRS.

I also have a 25-30 mHz export free band, multi mode, Optima 50W CB, on a 1.6m whip, and a uniden 5w PRS base set on a short whip all hard mounted in the landy.

When I need to get serious I have a Yaesu 857D all band HAM transciever in a water proof box and throw up a par-end fed on a 30' squid pole. I regually talk to a friend in France when I on hunting trips. This draws 23A on transmit so you have to be carefull not to flatern the battery.

The little cheap Wouxun kicks ass when I compared it against friends expensive name brand PRS handheld. It was only 1/3rd the cost also. But you do have to know how to program them.

The old landy was a army radio truck and every bit of the coach work is bonded so it makes a good ground plain. When I set up a station I'm in the habit of checking the SWR on an antenna tuner as getting this right is important as the antenna won't work and the radio won't drive an antenna unless it has the right reactance.


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petefj40
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Re: HAM Radio (Amateur Radio)

Postby petefj40 » Thu Mar 27, 2014 1:20 pm

Thought I'd throw this link up in the thread.
I'm selling my ICOM IC-25A compact 2 meter FM mobile transceiver.
$1 Reserve.
http://www.trademe.co.nz/Browse/Listing ... =711054638

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