Any electronics guru's out there?

[M61A1]

I'm a do it myself type of person. What I want is a comms system that I can select to transmit either vhf or uhf, but listen to both all the time ( and/or maybe select one or the other). A 2 place intercom option incorporated wouldn't hurt either, so I can put one in my drifter when it's finished. I would like to make this from off the shelf components.

 

So does anyone have any circuit diagrams for such a device that they are willing to share?

 

 

[Tomo]

What I've seen done, and will be doing in my plane is just putting the UHF speaker output through the headset earphones, and for mic just use the hand held mic from the UHF.

 

Worked really well in the 182 I used it in at the time! And much simpler than trying to tap into the UHF mic system with a PTT etc...

 

 

[rankamateur]

I'm a do it myself type of person. What I want is a comms system that I can select to transmit either vhf or uhf, but listen to both all the time ( and/or maybe select one or the other). A 2 place intercom option incorporated wouldn't hurt either, so I can put one in my drifter when it's finished. I would like to make this from off the shelf components.So does anyone have any circuit diagrams for such a device that they are willing to share?

This is exactly what Reg puts in the Savannah s for farmers. It is a harness off the shelf that connects the xcom 760 to a tiny electrophone Uhf and an intercom. Only short coming is that you can not transmit on the UHF using the pax PTT switch, not sure about the VHF, never tried. Also can't hear UHF when the VHF is recieving because it takes priority, as it should.

 

 

[M61A1]

This is exactly what Reg puts in the Savannah s for farmers. It is a harness off the shelf that connects the xcom 760 to a tiny electrophone Uhf and an intercom. Only short coming is that you can not transmit on the UHF using the pax PTT switch, not sure about the VHF, never tried. Also can't hear UHF when the VHF is recieving because it takes priority, as it should.

Sounds perfect,So where do I find it?

[rankamateur]

Get onto Reg at Aerokits and he will help you with a source of the harness. I just googled the 760 and apparently the intercom is actually built in to the Xcom 760. I will PM you a contact so I don't P off the moderator.

 

 

[ahlocks]

.. I will PM you a contact so I don't P off the moderator.

Awww... The moderatti aren't that hard to get along with.

 

 

[bones]

Only short coming is that you can not transmit on the UHF using the pax PTT switch, not sure about the VHF, never tried.

Yes the VHF is usable from either side, you can buy the complete harness and the modified UHF directly from Microair also.

 

 

[Kyle Communications]

The Xcom 760 is the one I use with that exact system. I wired in a GME3100 it is the tiny 5watt UHF that is cheap and it weighs only a couple of hundred grams and is the size of a 25 pack of cigarettes. You have a switch that selects which one you transmit on but both audios are always heard and the airband always takes priority. The main issue is forgetting to flick the switch back to air band. I am thinking of making a timer to autoswitch the airband back onto the main transmit after a time delay. Its not hard to do could even make a adjustable timer to do it. The Xcom has a inbuilt intercom and so does the microair. I selected the Xcom after a lot of research and have been extremely pleased with it. It has never missed a beat. I had it running in my workshop here for 6 months 24hrs a day before I installed it into the savannah.

 

Mark

 

 

[Kyle Communications]

I have the schematics here somewhere for the Xcom harness for the UHF mod but it is pretty much the same for them all the way it is swtiched. The GME also needs to be slightly modified as well but not much just a smd capacitor fitted to do some dc blocking on the audio rail

 

 

[eightyknots]

I selected the Xcom after a lot of research and have been extremely pleased with it. It has never missed a beat. I had it running in my workshop here for 6 months 24hrs a day before I installed it into the savannah.Mark

Whoa, a strange comment coming from someone who is a Supplier of Vertex Radios

 

Seriously though, how do you think they compare with the Microair?

 

 

[Kyle Communications]

Not strange at all really.....I am a icom premium dealer...the Icom is a great radio but was too big in my opinion and Vertex do not make anything except handheld airband radios so the only real option was Microair or Xcom. I have worked on the Microair (I wont tell you what I think of them) and also found out a lot more info on both radios...I made my decision on information and personal experience....I chose the Xcom....and am very happy with my choice

 

 

[rankamateur]

Gundy Greg had trouble with his Microair at Natfly about three years ago and the nice people at Jabiru lent him a brand new one still in the plastic wrap, to get him home where he could get his repaired, that is the only Microair I know of that has given trouble.

 

 

[Kyle Communications]

well I have 2 of them here ...they are both stuffed...one drops out of lock regularly the other is spurious...looks like a xmas tree on the spectrum analyser....the seem to have VCO and PLL issues the guys bought new radios....I know one guy who has had 5 of them replaced...not saying any more

 

 

[M61A1]

The Xcom 760 is the one I use with that exact system. I wired in a GME3100 it is the tiny 5watt UHF that is cheap and it weighs only a couple of hundred grams and is the size of a 25 pack of cigarettes. You have a switch that selects which one you transmit on but both audios are always heard and the airband always takes priority. The main issue is forgetting to flick the switch back to air band. I am thinking of making a timer to autoswitch the airband back onto the main transmit after a time delay. Its not hard to do could even make a adjustable timer to do it. The Xcom has a inbuilt intercom and so does the microair. I selected the Xcom after a lot of research and have been extremely pleased with it. It has never missed a beat. I had it running in my workshop here for 6 months 24hrs a day before I installed it into the savannah.Mark

As far as switching, I was thinking of just using double throw momentary s/w as a ptt. Select one direction as UHF, the other as VHF.

[rankamateur]

As far as switching, I was thinking of just using double throw momentary s/w as a ptt. Select one direction as UHF, the other as VHF.

That sound simple and fool proof, it is embarrassing to transmit a UHF call to your wife on VHF airband radio, but it happens from time to time with the system Mark is talking about.

 

 

[Kyle Communications]

That would be a bit hard when mounted on a joystick..with the right switch type maybe. I am happy with mine the way it is the only mod maybe to have two leds one red and one green. Red of aviation selection and the green for UHF so at a glance you can see what position the switch on the dash is in...quite easy just change the switch from a single pole to a double pole toggle and the necessary resistors and wiring

 

 

[Virago]

NAT (Northern Airborne Technology) make a small adapter box specifically to interface commercial radios into aircraft audio systems. We used them when fitting UHF CB's etc and when fitting forestry dept FM radios to the fire bombers. A simple method of interfacing the receiver audio is to fit a 15 ohm 5 watt resistor in place of the speaker and then take a 470 ohm 0.5 watt resistor from the high side through a switch into the headphone line. Always worked a treat for me. John.