VHF radio choice

[will kirkbride]

Does anyone have a preferance for Microair as compared to I-Com for coms in their aircraft.I have to choose in the near future and have used both but would like to hear others likes/dislikes problems or otherwise of these radios so I can make a more informed decision. I will probably fit a transponder also of the same make.Thanks

 

 

[Guest davidh10]

I use an Xcom, which I quite like. It was in the aircraft when I bought it. During my training, I was using Microair. They are both good radios. Haven't used an Icom, bit it is also a reputable brand.

 

If you visit the respective manufacturers web sites, you can download the full manuals, which may help you decide, as you see how to use them, not just a feature list.

 

Dual com is the way to go.

 

 

[Kyle Communications]

I have just made that decision for the Savannah I am building. I am a Icom premier dealer and I selected the Xcom for my Sav. The reason first of all was size. The IC-A210 is too large and the weight also more as mine of course is limited to 544kg (at this stage) I went for the smaller radio and after asking lots of questions to users of both the Microair and Xcom and reading all the specs and features I bought the Xcom. I also got them to supply the harness made up to suit a Savannah install. I have had the Xcom running in my workshop all day every day for the past 3 weeks and I have to say I am very impressed with it. I also got the harness fitted for a second input/output to suit a GME uhf radio I am using the super tiny GME 3100 which is the size of a small packet of cigarettes I pulled one from stock and wired it up and have tested the harness for full operation of the intercom and transmitting options in the Xcom with the UHF as well and it works beautifully. I am very happy with my decision and would recommend the Xcom to anyone. I have also done performance tests on the radio because obviously this is what I do for business and the radio meets all the advertised specs

 

Mark

 

 

[Guest Maj Millard]

I bought my aircraft with a Microair VHF installed with intergrated intercom. I then deactivated the internal intercom and installed a Sigtronics SP4 intercom, which is about as good as you can get, and the one everybody else has copied. I use cheap Xcom headsets (before Ian offered his) and these are the same as the Rec Aviation ones Ian now offers. The reception /transmit is clear as, at all times, both on the VHF and intercom. You could not possibly want better.

 

Buying the world's best (or most expensive) headsets won't give you good radio/intercom if the system that they hook to are shxx. If the radio/intercom system is installed correctly, you'll get great performance, even from cheap headsets.

 

I believe Ian now also offers the Sigtronics range of intercoms on the forum shop, and I can highly recommend them.

 

The Icom 'flip-flop' panel mount is a good system and does give you the option of quickly changing frequencies. It is widley usd in GA aircraft, and is reliable. The latest Microair VHF does also have the same 'quick-change feature and also a second freq monitoring capability.

 

As with any avionics installation, the wiring up of these systems is key, and must be done effectivly for top reliable performance with both radio and intercom.

 

The Sigtronics website has all installation wiring diagrams which you can easily download, and in understandable format so you can actually follow, and come up with a professional installation that works.

 

There is nothing nicer than crystal clear radio and intercom operation at all times, and nothing more annoying or distracting than a system that isn't up to scratch.

 

They have all diagrams for most radio installations including Microair, Icom and Xcom etc.............................................Maj...

 

 

 

[jakej]

I install avionics for a living so offer my opinion based on experience, yours my vary........

 

Basically you get what you pay for - and good audio/intercom isn't available in 'cheaper' 2 1/4" radios unless you have a good independent intercom eg PS Engineering (considered, by many, to be the best audio people around) or the Sigtronics. BTW ps-engineering.com have some 'auto squelch' models which means you don't have the ability to adjust the squelch, it happens automatically & adjusts each mic to suit whatever different headsets you have.

 

Xcom, in the past, (as from my experience) had 'issues' which were mostly unjustifiably blamed on wiring etc, this may have changed somewhat now that Narco (I believe) are involved in the manufacture of those units.

 

Microair seem to be ok ( I used to throw away the Intercom board on the older models) providing you use a separate Intercom unit, preferably NOT a cheap one.

 

Icom - they make good radios particularly the A200 but the design of the A210 is a shocker !! and it is not a true monitor of the standby frequency it scans it instead. There is no other ,generally used, radio that in order to fit it you have to remove the front panel first to install into the rack & reverse the procedure to remove it. The front panel is connected to the body by a semi rigid 10mm x .5mm (approx) ribbon, Again IMO this has given some Icom owners a headache with having warranty repairs done due to issues with the ribbon cable - also I think the dual watch feature is a poor attempt to mimic the the Garmin SL40 (aka Apollo SL40) you have to 're engage' the dual watch each time someone talks on the active frequency or your pax speaks into their mic.

 

Garmin SL40 - These units are so reliable and troublefree & have 2 years warranty. They really do monitor the standby frequency without any further, after activation, pilot input. The SL40 has only ever had one Service Bulletin issued in it's long history, the same can't be said of others.

 

Some owners tend to blame the equipment however if the wiring, antenna cabling, shielding, grounding & bonding is up to scratch then there should not be any problems other than poor electrical design/ layout. Some prefabricated wiring harnesses can introduce problems too especially when they use the braided shield as an earth return - to be discussed another day :-)

 

 

[eightyknots]

How wonderful to have all this collective wisdom amongs RecFlying members. This is fantastic information sharing in action!

 

 

[mattbutton]

Xcom have come a long way in the past few years, the product is now very refined, I can spoke with authority in this matter, as I manufacture components and metalwork for Xcom, as well as Narco

 

Would I recommend and use a Xcom radio, yes.

 

 

[Guest davidh10]

.. As DavidH10 said - Dual com is the way to go, although not sure David if you are referring to dual radio's or dual frequency reception mode as is the case with the Icom (& the others new models I seem to recall)....

Dual channel monitoring in the one radio. Both the Xcom and the Microair do this.

 

You select a Primary and a Secondary channel. The secondary channel is monitored and it polls the Primary channel for a signal. If it detects a signal on the Primary channel it locks to that channel until the signal stops, then resumes dual channel monitoring. If a signal appears on the secondary channel, you hear it with very short breaks (only a few milliseconds) as it polls the Primary channel. This also provides an audible indication that you are listening to a transmission on the secondary channel.

 

PS. Both units have built-in vox operated intercom which works well, so no need of an external unit.

 

Having two channels is great as I can monitor Area as well as CTAF, two CTAFs or operate on a private frequency and monitor CTAF or aera as needed. This latter is handy when flying formation to keep the command channel off the CTAF or when flying in groups, where we assign different aircraft to monitor different frequencies and communicate air-to-air on the private channel.

 

 

[will kirkbride]

Thanks for all the replys. Really makes it worthwhile to visit this forum. Now I have lots of time to follow up on all your suggestions via the various manufacturers websites etc. Keep the suggestions comming also about the importance of the antenne wiring etc. Cheers

 

 

[jakej]

Now I have lots of time to follow up on all your suggestions via the various manufacturers websites etc. Cheers[/quoteReading is one thing, understanding is another - those guys are just trying to sell you their products so therefore are biased.

[Guest Andys@coffs]

It probably isnt well known, but the original RF designer of the microair and the xcom is the same person. The microair came first then the xcom. Of course after the original design came the incremental changes and they maynot have necessarily come srom the original designer. I guess my point is that the RF parts of the 2 radios are probably not all that dissimilar and as such the choice might come down to how comfortable you are with the through life support.

 

Major makes the point that good headsets and a crap radio/intercom will a crap result provide, I also contend that similarly a good radio and crap headsets are equally useless. I dont understand these days why everyone doesnt use ANR based headsets. If you ever get the chance try one and I seriously doubt you'd go back to only passive noise reduction headphones (although its still an essential part of a good ANR design)

 

In fact, perhaps its far thinking but the whole VHF AM radio approach is so 1900's and we could all do with a quantum change in technology here. I find it amazing that we all fly with mobile phones and the audio on those is far superior to a crappy AM radio. Add in poorly attenuated engine and wind noise and a smattering of english as a second language and its amazing that as much communications gets through as it does. Its time that the radios went digital. Further if digital and tied to a GPS you should be able to dial in a range such that "I only want to hear calls that are within 20nm of me" of some other user selectable range or quadrant that depends on where you are and where your going and the same of the other party.

 

Andy

 

 

[jakej]

Hi Andy

 

Some makers do use better technology but that comes at a price (get what you pay for) so isn't available in sub $1200 radios. Problems with radios can be more basic than the radio itself -more to the point is wiring and installation issues, it's like the foundations on a building, good design etc means no cracks. Take audio shielding for example, the best audio engineers, PS Engineering, (IMO) and others more qualified than most of us say you should not use the shield (braid) as a ground return to reduce 'ground loops' - guess what, Xcom & Microair wiring looms do that, no wonder some people have audio issues.

 

Then there is the practice of using RG58 coax antenna cable, it has/does worked for many for a long time but low loss cable eg RG400 is much better (I won't use any other) as it has a more dense and double layer of shielding. The benfits are more evident on composite airframes. The crimp type coax connectors are much better too - I through away any screw type I get supplied with a radio, just not worth using due to the potential for problems later.

 

Modern avionics are more sensitive, particularly non Tso'd units, to RFI/EMI and therefore need the advantages of quality cabling etc. It's interesting to note that manufacturers of new Part 23 aircraft are not allowed by the FAA to use RG58 anymore.

 

Many other audio/radio problems are caused by poor grounding/bonding of antenna and earths - In my experience most of the problems with radios/audio are as a result of some or all of the above, most radios will work properly out of the box.

 

Jake

 

 

[eightyknots]

In fact, perhaps its far thinking but the whole VHF AM radio approach is so 1900's and we could all do with a quantum change in technology here. I find it amazing that we all fly with mobile phones and the audio on those is far superior to a crappy AM radio.

You are right, AM (as well as FM) are 1900s technology. But so are toasters, mobile phones, tractors, helicopters, satellites and aeroplanes. All are still in use today.

 

 

[Guest davidh10]

I think you'll find, Andy, that VHF aviation radio has used frequency modulation (or FM) for many decades now, not AM as you state.

You would think it would be better to use FM for man made noise rejection, but no... its AM.

 

Excerpt from the XCOM Specs:

 

• 118.000 to 136.975 MHz, 760 channels transmit and receive (AM) receiver
  sensitivity AM (118 – 136.975 MHz.): not less than 12 db SINAD for 1.5 uv
  (30% AM at 1 kHz. audio)
   
   
  
• 108 to 117.975 VOR receive only audio (no nav) receiver sensitivity AM (108
  – 117.975 MHz.): Not less than 12db SINAD for 2.0 uv (30% AM at 1 kHz.
  audio)
   
   
  

 

 

Another advantage of FM over AM would be that with FM the strongest signal will capture the demodulator (discriminator) and you hear that signal quite clearly. With AM you usually get the audio clobbered with the heterodyne between the two carriers that aren't quite on the same frequency. On the other hand FM needs wider channel spacing, even when using narrow band FM, so it was probably an available spectrum and radio front-end bandwidth issue that decided the matter. Second thoughts, maybe it is good to know that one station got clobbered... then you know there's two transmissions!

 

 

[eightyknots]

Far out: I'm shocked that AM is still used in aviation communications! Marine comms has been FM for a long time, and that's on the VHF band too.

 

 

[Kyle Communications]

The FAI and ITU determine what modes and frequencys are used worldwide and also in what areas. The aircraft industry takes 100 years to change just look at continental and lycoming..their engines are still 1940's technology when there are much lighter more fuel efficent and more reliable engines available but it takes so much paperwork crap to change 1 bolt that it becomes a exercise bigger than Ben Hur to do anything....the radio side of things is the same.New digital modes with FEC (forward error correction) are in use everyday all over the world and have proven to be much better than analogue systems in most cases. IDAS which is the new digital mode used by Kenwood and Icom prove you can get 15% further in communication distance with the FEC built into the system. Also it allows identification and other many different option in the data stream. Within the IDAS signal a substream with text at 1200 baud can be used that sits simultaneously with the voice carrier. now all of this is done on a 6.25khz bandwidth. To change the system world wide is a massive job mainly all international aviation drives this stuck in the mud feature. To change anything is just too big a job with all the buroccracy (sorry cant spell)

 

Mark

 

 

[jakej]

I know who ITU (band 8) is but what does FAI http://www.fai.org/ have to do with aviation communications ? FYI there is talk of digital radio but, for aviation, that would mean everyone changing radios so probably won't happen anytime soon.

 

Jake

 

Mark

 

 

[Kyle Communications]

Hi Jake

 

The FAI have a huge influence in all aircraft operations be it regulations or processes they are part of the overall governing body for aircraft and also aerospace. They are consulted and are members of the boards that us underlings dont get to be a part of. All of these NGO's have a hand in global decisions on these matters that affect each other. In the text below the last 2 lines are the most relevent the FAI are one of the organisations that make these decisions on a worldwide basis

 

The current statutes describe in detail its specific objectives:

 

to make evident the essentially international spirit of aeronautics as a powerful instrument for bringing all people closer in mutual understanding and friendship regardless of political, racial or religious considerations, thereby helping to create international good will and thus build a better and more peaceful world;

 

to bring together the air sports men and women of the world in international competition;

 

to educate young people through sport in a spirit of mutual understanding and friendship;

 

to coordinate its Members' separate efforts to further aeronautics and astronautics throughout the world;

 

to protect and safeguard the interests of its Members in the use of air space;

 

to provide a forum for the exchange of information and discussion of mutual problems with other elements of civil aeronautics.

 

 

[jakej]

Hi Mark

 

Understand all that but FAI has really nothing to do with the Radio communication spectrum or regulation of same, here is the quote from their website front page"FAI is the world governing body for air sports and aeronautical world records." Their Technical Commissions on Airspace and Navigation Systems have nothing to do with communications - just wanted to set the record straight

 

Maybe you meant to say ICAO ?

 

 

[Kyle Communications]

Hi Jake

 

I was reading a article a few years ago you may remember there was a big push to change the airband mode and some of the ops as AM mode has been so out of date for so long as comms go now and I was sure the FAI were mentioned as part of the submission group for the process. I tried to find where I read it but cant at the moment. The ICAO would certainly have a major input to the decisions. Trying to get anything changed worldwide in the aviation area is like converting a muslim to a catholic ....almost impossible

 

Mark

 

 

[jakej]

Mark

 

You could be correct there but the FANS (Future Air Navigation systems) committee would be more relevant than FAI. I don't see any chance of changing over to FM or Digital aviation radios anytime soon. Imagine the cost to us all.

 

 

[Guest Andys@coffs]

You are right, AM (as well as FM) are 1900s technology. But so are toasters, mobile phones, tractors, helicopters, satellites and aeroplanes. All are still in use today.

Indeed all those things are in use today because fundamentally they are still as good as it gets. No one has yet created an alternative device that toasts bread any better or more cost effective than teh current technology.

 

The same can most definately not be said for AM based transceivers. The equivalent to my thinking is us continuing to use horse and cart for interstate travel.

 

It would be relatively easy, to make a new digital radio that meets the intent as I identified above and make it also "backward" (pun intended) compatible where the backward compatibility could be turned off by pilots choice when the luddites catch up. I suspect our IP protection laws and patent stupidity is likely stiffling progress here with some patent holder, like the majority of the non flying public, having a view that flyers are typically rolling in it and they need to have the maximum $$ extracted from them where ever possible.

 

Andy

 

P.S Jake, Im ex RAAF Radtech air so can speak the lingo and have dealt with most of the issues you raise. Single shield coax has no place in a modern aircraft, after all the coax has to work damn hard to make up for the inherent failings of the VHF AM system :<)

 

 

[Guest Toally87]

Most of the radios can be good, it's all in the setup, get someone who knows how to put it in to help you or do it.

 

Toally

 

 

[bilby54]

Hi Will,

 

Throw the pamphlet for the Icom A210 in the bin before you part with the cash! As mentioned earlier, they are shockers!!

 

I had an early Xcom in my Drifter for about ten years and apart from a minor fault that was fixed under warranty, it worked a treat. Icom needs to go back to the drawing board.

 

Cheers

 

 

[djpacro]

I have an ICOM A210 as does a sister aeroplane. Works great for us including the monitoring of the standby frequency which a poster commented on some time ago. There may very well have been better choices for us back then (2 or is it 3 years) but no complaints for these flying school aeroplanes.