Hand Held Radios (ICOM)

[TROOPER]

Just wondering if anyone has had any experience with the ICOM IC-A15 VHF airband radios, fitted as main radios in gyros.

I'm looking at replacing a MicroAir M760 (with the MicroAir/Mobile One/Rojone) antenna with something more reliable, and that covers the entire bandwidth of 118.000MHz to 136.975MHz.

Trooper

[tonydenton]

you should ask chook , he would have the tech answers for you. chook has had posts on here recently so if you search his name it will come up for sure., .

[RossM]

[chook]

Hi Trooper.

Here are my notes for the A15

IC-A15 [IMG]file:///C:%5CUsers%5CWayne%5CAppData%5CLocal%5CTemp%5Cmsoh tmlclip1%5C01%5Cclip_image001.gif[/IMG] Simple operation [IMG]file:///C:%5CUsers%5CWayne%5CAppData%5CLocal%5CTemp%5Cmsoh tmlclip1%5C01%5Cclip_image001.gif[/IMG] Rugged construction [IMG]file:///C:%5CUsers%5CWayne%5CAppData%5CLocal%5CTemp%5Cmsoh tmlclip1%5C01%5Cclip_image001.gif[/IMG] Output power 5.0 W (PEP) 1.5 W (CW) [IMG]file:///C:%5CUsers%5CWayne%5CAppData%5CLocal%5CTemp%5Cmsoh tmlclip1%5C01%5Cclip_image001.gif[/IMG] Loud audio output (BTL Amplifier - 700mW) [IMG]file:///C:%5CUsers%5CWayne%5CAppData%5CLocal%5CTemp%5Cmsoh tmlclip1%5C01%5Cclip_image001.gif[/IMG] Full air band coverage (118-136.975 Mhz) [IMG]file:///C:%5CUsers%5CWayne%5CAppData%5CLocal%5CTemp%5Cmsoh tmlclip1%5C01%5Cclip_image001.gif[/IMG] 200 memory channels (8 character alpha tagging) [IMG]file:///C:%5CUsers%5CWayne%5CAppData%5CLocal%5CTemp%5Cmsoh tmlclip1%5C01%5Cclip_image001.gif[/IMG] BP232N Li-Ion battery supplied (18 Hrs typical) [IMG]file:///C:%5CUsers%5CWayne%5CAppData%5CLocal%5CTemp%5Cmsoh tmlclip1%5C01%5Cclip_image001.gif[/IMG] Side tone function, with standard G.A. headsets [IMG]file:///C:%5CUsers%5CWayne%5CAppData%5CLocal%5CTemp%5Cmsoh tmlclip1%5C01%5Cclip_image001.gif[/IMG] Auto noise limiter (ANL) reduces pulse noise [IMG]file:///C:%5CUsers%5CWayne%5CAppData%5CLocal%5CTemp%5Cmsoh tmlclip1%5C01%5Cclip_image001.gif[/IMG] Water resistant construction (IPX4) [IMG]file:///C:%5CUsers%5CWayne%5CAppData%5CLocal%5CTemp%5Cmsoh tmlclip1%5C01%5Cclip_image001.gif[/IMG] This radio is available under the terms of a special permit from the ACMA and does not meet the current ACMA standard. Users should assure that the radio meets the performance requirements of their particular application.

NOTE THE LAST DOT POINT.

Hmmm Microair - I have recently installed an XCOM as a replacement for a faulty M760 because the Australian distributor would not repair it - he was prepared to sell my customer another M760 however so the backup and service is non existent. Sad really as they are both Australian radios in one form or another. The XCOM on the other hand is well supported here in Australia and we generally have access to their tech and designer - a most fortunate situation in today's global environment. The XCOM also comes with a premade wiring loom option which is where most guys have problems trying to get their home made wiring to function correctly (never mind the intricat soldering skills required). Incidentally other than owning and using an XCOM myself I have no affiliation with them.
I find the most important part of any radio installation (especially gyros) is to place a 22,000 microfarad capacitor in the power circuit as close to the radio connection as possible.
\Interestingly the installation notes on the website for the Microair are very well written and also should be used for any radio installation.

Regards.....Chook.

[tonydenton]

I told you he would have the tech answers for you .

[TROOPER]

Thanks Gents,

I've purchased an IC-A15 and am in the process of making a mount up for it. The MicroAir M760 radio seems to be good, but their customer assistance is non-existent and they did not appear interested whatsoever. The problem 'seems' to have come about with the independent ground plane antenna that MicroAir sell. They advertise them as an aviation antenna for 118.00MHz to 136.95MHz, however this is not the case. Testing by a couple of techs have shown that this antenna only receives and transmits on a very narrow bandwidth. I purchased the machine, with the antenna installed, from Wondai where the multicom channel of 126.7 exists. It would work perfectly down there, however here at home the CTAF is 132.9MHz which is too far from the bandwidth of this antenna. Inquiries to identify and source another antenna proved challenging to say the least, so the handheld ICOM IC-A15 was purchased as the preferred option.

I've lost all confidence in MicroAir as their policy forbids their techs from talking to anyone. They request an email which they hope to be able to answer within two weeks, which is as useful as a screen door in a submarine when one is standing in the hangar with a radio tech who is working on the equipment and scratching his head for more information in order to be able to resolve the problem.

I'll be looking into XCOM for my next 'bird'.

I've since spoken to a number of others who have experienced similar problems with this company, including dealers/repairers/agents who have had trouble dealing with them as well.

I'll let you know how I go with the handheld. I'm just trying to work out a way to charge it during flight so that I don't have to keep taking the radio out of the case and putting it on charge in between flying days. Information suggests that charging directly during flight has a distinct risk of interfering with transmission and reception.

Regards,

Trooper

[chook]

Trooper unfortunately the A15 as far as I know will not work directly from your gyro 12 volt system - you have to recharge the battery packs which would mean an in flight battery change if it goes flat. The A15 was specifically designed as a ground personnel unit (not aircraft mounted and this is where the ACMA restriction above comes into effect) if I remember correctly as a replacement for Icoms A6 handheld. (that's a whole other story)

Yes Microair are gaining an unenviable reputation.

The independent ground plane antenna that Microair sell is possibly manufactured by Mobile One in Sydney who have just resold their business to

Mobile One Australia Pty Limited

Announces that the Manufacturing Business has been SOLD to ROJONE PTY LIMITED.
For ALL SALES ENQUIRIES please contact ROJONE on 02 9829 1555 or warren@rojone.com.au



You could contact Rojone and enquire about their current range and whether it can be tuned to your local area frequency probably by one of your local techs using a SWR meter. (A radio tech will know about this process).
Using the "rubber ducky" antenna which comes with the A15 will be very disappointing and probably more unmatched to your A15 than your current independent ground plane unit. Again you will need to have your radio installation SWR checked which ever way you decide to proceed as it may be that your current antenna has a fault or is so far out of tune that it has caused the M760 to fail.


Regards..........Chook.

[RossM]

Hi Trooper,
The antenna is most likely tuned for 124 MHz.
When you get to about 4 MHz either side of the tuned frequency, the performance drops dramatically.

See image here, below the air band radio
http://www.mobileone.com.au/5b_airband.html

You can contact Warren at Rojone, and order a air band antenna tuned for you required frequency. You ask that it be centre tuned to what frequency that you want.

Another thing that chook may be able to confirm, or a wives tale, is to have cable from antenna to the connector in lots of 700mm

read this article
https://www.cumulus-soaring.com/xcom...es%20Guide.pdf

ROJONE Pty Ltd 15 Minigwal Loop, Waikiki, Western Australia 6169 Tel: +61 (8) 9592 9606 Fax: +61 (8) 9592 6160 Mob: 0407 426 233 www.rojone.com.au | warren@rojone.com.au ________________________________________

[chook]

Comment by Chook.
Ross thanks for presenting your response. As to your question "the length of the coax should be in lots of 700mm".
In my experience the shorter and most direct route that the coax is run between the radio and the antenna is best. The XCOM article that you have presented mentions that there are 2 types of coax that we as aviators should use - RG58 and RG400. If you use the cheaper (and in most cases adequate) RG58 it does have a higher "leakage" figure than the RG400. This leakage allows the signal to partially "escape" and for other signals to enter the coax and cause interference. And if you bend the coax or store it in a roll tucked up somewhere in your aircraft then this will change the physical structure of the outer coaxial mesh, the insulating foam and the internal "hot" wire. This change can also contribute to a higher SWR figure which is not what we want.
So essentially if you have 2 distances (and 2 lengths of coax) then it is possible that the longer length of coax cable will introduce a worse reading than the shorter distance and this may be where the confusion about specific lengths comes from.

The other consideration for the path that the coax takes is to keep it away from high current sources and other cables in general (starter cables, ingnition cables, strobe cables etc). This will avoid interference into and from the radio coax.

Regards....Chook.

[RossM]

if you want to build your own antenna

http://chrusion.com/BJ7/InvVeeAntenna4ULs.pdf

[aussie_paul]

I flew several RAFs in NZ fitted with dipole type antenna.
They proved quite good and as we were operating in
controlled airspace most of the time they needed to work. (Y)

Aussie Paul.

[RossM]

Hi Trooper,
Check that you don't have to buy the whole "airkit" antenna. that is if that is what you have. Just a replacement antenna (top part) tuned to your frequency.
The standard airkit antenna is called M124. but having it tuned to say 132MHz, it would be called M132
Confirm that the rubber duckie part does not need to be changed (maybe it does)

Regards....Ross

[TROOPER]

Thanks Gents,

This 'black magic' radio stuff is definitely starting to make my head spin.

I'll just have to see how the IC-A15 goes in the air as their brochure states "(For ground and air operations)". I read that as a suggestion that it should also work in the aircraft as well on the ground.

I did consider getting another 'airkit' antenna for my local area (132.9MHz) but quickly disregarded it as I thought that it was mandatory to be able to receive the emergency frequency of 121.5MHz. Apparently these antennas have a very narrow band width so that if I had it tuned for my CTAF of 132.9MHz, I would not be able to get the emergency frequency as it would then be too far away from the antenna's tuned frequency.

I did contact Rojone about a replacement antenna, however they advised that they are a number of weeks off being able to manufacture any antennas. Apparently they purchased the manufacturing rights from Mobile One, but not any parts to get them started, which is what they are waiting on to arrive before they can manufacture themselves.

There is only one radio tech in my area who did the testing on my M760 and airkit antenna in the gyro. He mentioned that it had a very high SWR count (whatever that means) and couldn't explain why. He advised that the SWR count was so high that it could easily damage the radio if used. This tech is the only one I could locate within a large area. The nearest others are 90kms to the north in Cairns, and 150kms to the south in Ingham. Before locating this local tech, I contacted the others and was waiting a number of weeks for the Cairns or Ingham techs to visit the area where the gyro is hangared however they do not wish to travel that distance. That is when I finally managed to locate the local one who was recommended by a computer shop. I just started calling computer shops and the like asking them if they knew of any techs in the area.

I looked at purchasing and installing a Comant CI-122 antenna (mounted under the aircraft) which had been recommended by some outlets (as long as I mounted it on a minimum 350mm diameter aluminium disc, however I had to discount that option (the same applied for the RAMI AV-17). Once I got the dimensions of the antenna I realised that it would only clear the ground by 50-70mm which would pose a high risk of damage to this $450+ antenna (in addition to installation etc.) on taxiing, takeoff or landings, especially on grass strips where the antenna would almost certainly drag on the grass.

Ross, thanks for the information on building an antenna, however when it comes to this subject my knowledge and abilities fall a long way short. Seriously, I have no idea how to even tune a television in. Thankfully though, the broom pilot does!

Kind regards,

Trooper

[tonydenton]

yeah well all you TECH HEADS lost me after you said " hi trooper ".

[TROOPER]

yeah well all you TECH HEADS lost me after you said " hi trooper ".

Trust me, I've been called a lot worse.......and often!!!

[RossM]

The top of my antenna fell out from the mobile one airkit.
Covered by 5 year warranty.
They sent me another antenna. I asked to be tuned for 126MHz
see image attached, lowest point is about 121MHz






Chook may be able to say what this means

Regards...Ross