2M or Airband?

[bignos]

Im a noob to paramotoring but have had ppl and flown gliders.

Im a little confused about which radio to buy, im told that 2m is the one that most PPG pilots use to contact each other in the air, however the airlaw section on this site says that its illegal to use it in the air.

Airband makes sense if i want to fly into my local microlight or gliding club, and i have a licence because of my old ppl.

Im considering getting a radio that does both but am not sure.... any help is welcome!

[Phil_P]

There are no radios that we have been able to find that cover both VHF and airband that will give you the required AM transmission required on airband.

This is a subject that has been covered in previous threads if you do a search of the forum, and opinions are divided. Those with an aviation background seem to tend to favour airband, whilst those who would have to go through the hassle of the FRTL course tend to prefer VHF.

There is a select band of geeks who will try to use both , with an interface to allow both to be hooked up to your headset.

[bignos]

There are no radios that we have been able to find that cover both VHF and airband that will give you the required AM transmission required on airband.

This is a subject that has been covered in previous threads if you do a search of the forum, and opinions are divided. Those with an aviation background seem to tend to favour airband, whilst those who would have to go through the hassle of the FRTL course tend to prefer VHF.

There is a select band of geeks who will try to use both , with an interface to allow both to be hooked up to your headset.

I dont understand? am?

air band is defined as : 'Airband is used to mean the VHF band between 108 MHz and 137 MHz'

but 2m band is : 'The 2 meter amateur radio band is a portion of the VHF radio spectrum, comprising frequencies stretching from 144.000 to 146.000 MHz '

so a set that covers the range 108 - 146 would cover both bands would it not?

[Guest]

Airband uses amplitude modulation to carry the message over the carrier wave whereas the 2m band uses frequenct modulation of the carrier. There are sets such as the VX-7R and others that are capable of both but most find it easier to carry a specific set for whatever your need is on the day.

[Phil_P]

As Ian has pointed out, the two modes of transmission are AM (amplitude modulation) and FM (frequency modulation). It is important to realise that the two are NOT compatible. Airband is exclusively AM, nearly all reasonably priced 2m (144 mHz) transceivers are FM sets.

Does the VX 7R actually transmit in AM Ian? I know that my VX 2R switches to AM when on the airband frequencies, but that is only in the receive mode. If you transmit on that frequency, it still transmits on FM despite the display showing AM in the mode.

[macey2kk]

i cant answr the technical fm am bit of this post - but i do use a "unlocked" ( remove the solder blobs ) vx-7r which communicates very well both below and above 144mhz.

cheers

[Guest]

Does the VX 7R actually transmit in AM Ian? I know that my VX 2R switches to AM when on the airband frequencies, but that is only in the receive mode. If you transmit on that frequency, it still transmits on FM despite the display showing AM in the mode.

Never managed to get a definitive answer on that one when I made enquiries. I sold my 7R to Simon Payne as it transmits at 5W at the upper end of the airband range but the transmit power tails off to 2.5W at the lower end of the airband which was not a problem for Simon as he wasn't planning to transmit on that band. For airband work I find the dedicated airband Vertex Standard sets such as the 220 and 300 are far better than the Yaesu multi-band compromise units despite being made by the same people.

[alan_k]

I have studied the specifications for the VX-7R. It only transmits AM on the 6m (50MHz) band, so the air band is FM on transmit, not good.

Safe flying,

Alan

[Guest]

i have a 2 mtre radio and aint a clue how it works how far they travel would slim give me some advise on using it

[slim]

i have a 2 mtre radio and aint a clue how it works how far they travel would slim give me some advise on using it

Some clues on make and model would help but even then I'd still be trying to find a manual. There are so many different makes and models out there and somehow everyone thinks they've come up with a better user interface than the last bunch so they all work differently.

The key things to find out are:

• 1) how to change the frequency so you can set it to the same frequency as your mates
  2) how to change the power output so you can set it as low as possible for what you're doing
  3) where the push to talk button (PTT) is so you can talk to people
  4) where the volume control is so you can hear people
  5) where the squelch control is so that you only have to listen to proper transmissions and not loads of static noise
  

The thing that everyone forgets is that once you press the PTT you need to wait just a moment to allow your transmitter to stabilise and the squelch control on the other end to open before talking. If you don't then the guys at the other end only ever hear the end of your sentence.

You asked how far radio waves travel. The answer is ... a long way except when there's stuff in the way. With a 5w hand held you can easily talk to astronauts on the space station but you can just as easily have trouble talking to someone a couple of miles away on the other side of town. If there is line of site between you and the person you're talking to then you need very little power. If there is a hill in the way then no amount of power will get through it. 2m doesn't bounce over hills at all well. If you're ground based and trying to get hold of a pilot who's landed out in the next valley, the best thing you can do is get on top of the hill.

There - weeks of radio training in a paragraph

Happy to answer specific questions..

Stuart

[gazza_c]

Slim, a quick question! I have a jing tong 208 and a set of those speedair helmets with headsets. Now I dont really have the cash to go and buy the top of the range radio and headset etc would it be ok just to get a set of say 'goldstar' headsets and keep the jingtong? do you or have you used the jingtong and would you rate it to warrant me keeping it, if so can you upgrade the standard aerial if need be? cheers mate

Gaz

[slim]

Hi Gazza,

Almost any radio can be made to work with almost any headset. I've got a SpeedAir helmet with built in headsets and I use it with my Kenwood radio. The Jing Tong is a perfectly adequate radio. It is usually just a question of getting the right connectors wired in the right way.

With any communications system that operates in extreme environments there are two main places that improvements can be made and both involve the interface with the air. The first is the antenna - the interface between the radio waves and the radio. Most stock aerials that come with radios as standard are pretty poor so almost anything you buy will be better than the one that came with the radio. The thing to look for is the gain. The higher the gain the better as long as it is listed on the right band (an antenna with a gain of 3db on 70cm is useless on 2m but many are designed as dual band). Most handhelds havean SMA connector for the antenna. This is an international standard so they are usually interchangeable.

The other air interface is the microphone and speakers. You'd be amazed how good a cheap radio can sound with decent speakers and a good microphone

I know I haven't specifically addressed your detailed questions. That's because I'm not really familiar with the Jing Tong range or the Goldstar.

What I will do is track down a half way decent antenna like the Maldol AS-30F (that I use) and see if we can get SimonW to add it to the Paramotor Club shop.

Stuart

[irm750]

Hi Gaz

I use a cheap as chips Jingtong 208 and my mate is considering chopping in his posh Kenwood and replacing it with one!

They work well with the recommended drilled modification (http://www.g4ilo.com/jingtong.html) and an aerial upgrade. I chose a Watson WSMA-7000 flexible aerial which needed a female-female SMA connector to fit and a rubber O-ring to tidy the gap between radio body and aerial base. They are so well priced that if it breaks or I lose it then I will not need to get upset.

I use a modified autocom motorbike headset unit with monitors that screw into custom earmold earplugs with inline filters (which also double up for use while shooting and as straight earplugs without the radio).

Can't talk about the goldstar headset as I've not used one, but personally I wouldn't be in a rush to replace the Jingtong. It has everything that SLiM suggests for a 2m radio apart from the variable power, but it's only 2.5 watts anyway.

Just my opinion of course.

Best regards,

Ian.

[irm750]

By the way, the factory user manual for the Jingtong is hilarious but I found this to be a more useful guide which isn't in Chin-glish!

http://www.users.on.net/~endsodds/jingtong.pdf

Best regards,

Ian.

[gazza_c]

Irm750, don't suppose you could put a link up to show where I can purchase the connector for the watson aerial could you,I've looked on sites but got slightly confused!! cheers for everyones reply,gonna try the aerial upgrade first

[irm750]

I also got a bit confused when I started looking for a replacement aerial! Luckily I spoke to a guy locally at a small independant electronics shop who helped a lot and supplied what I needed.

The standard aerial which comes with the radio has a male connector on the bottom which screws into the radio. I couldn't easily find a suitable aerial with the right connector so went for the Watson aerial which has a female connector the same as the radio, requiring the connector. Over all this makes the connector on the new aerial a bit longer than the one on the original so I put a small rubber o ring inbetween the aerial base and radio casing to make it look tidy and to stop dust/damp getting in.

This is the connector I am talking about.

http://www.maplin.co.uk/Module.aspx?ModuleNo=26630

Hope this helps?

Best regards,

Ian.

[nirmal]

I think this is a super cool antenna mod. It wont be very expensive either.

http://picasaweb.google.es/clubmolinill ... DIPOLOVHF#

[Phil_P]

I think this is a super cool antenna mod. It wont be very expensive either.

http://picasaweb.google.es/clubmolinill ... DIPOLOVHF#

It's just a pretty standard 1/2 wave dipole by the look of it, using flexible wire for the elements (in fact the core of the co-ax forming one side of the radiator).

Thing is, although the little rubber antenna's that come as standard aren't the most efficient, because you have fantastic line of sight once you are in the air, you can get away with mediocre antenna's.

I've just mounted the standard antenna's onto the cage netting with zip ties, and hooked them up with extension cables.

[norman]

Quite a neat installation on the link.

[bignos]

how do i mod a vx7r to do both 2m and air band?

[huffhuff]

Hi bignos,

I did mine the other week, really quite simple.

1. Remove the battery and the black cover/sticker jobby directly behind (it's where you can add the SU1 pressure sensor thingy).

2. You'll see 8 or so numbered jumpers. Simply remove the solder from jumpers 4 and 5 (ie. no solder joining the top and bottom of the jumper. It needs to be a clear jump).

3. Now reassemble and reset unit. Keep radio switched off, press and hold the 4, band and v/m key whilst switching on (this is the trickiest bit of the procedure if you ask me).

4. The Yaesu logo should now be replaced with the Vertex logo.

NOTE: If you have the european version, you will need to google 'yaesu vx-7r european mod' as it is slightly different.

[bignos]

...so at last i can get a 2m band and airband communication handheld, i can both talk and listen on both bands, even thought the airband range will be limited - is that correct?

[huffhuff]

True - ish. Although you can TX and RX througout the range, the AM TX is actually through FM as far as I am aware (so not true AM TX capable). Plus, I don't think you can TX to the full 5w on this quasi am/fm. Obviously, although I can hear my local (very local) ATC>Pilot communication, I have not tried transmitting. I have however both transmitted and recieved to 2m frequencies and PMR.

To be honest, i'm not that up on it all but as you'll know from your previous posts, V2nb3, SLiM and now Alan K and Chris are really the radio guru's.

[alan_k]

Hi chaps,

One slight snag with using the vx7r on airband is that it is FM on that band, not AM.

If you tune the receive frequency off a little bit it can make the AM more intelligible, known as 'slope detection'.

The spec says it is AM only on the 6m (50MHz) band. Bu**er.

Alan

[slim]

The reality is that, because it cannot transmit AM on airband you won't be able to talk to anyone. All they'll hear, unless they detune their radio slightly (as Alan said), is fuzz and most likely they won't think to detune their radio so you'll just be pissing people off.

If all you're trying to do is talk to your flying buddies then use FM on 2m. If you need to talk to ATC then you'll be needing an airband AM transmission capable radio. There isn't a usable workaround.

As a bit of a teaser, I spent a lot of time at SPLASH yesterday talking to the CAA guys about radios and Mode-S transponders. I'll summarise the results in another post later.

Stuart