2 replies to this topic

[johnatti]

First of all thanks for allowing me to join in. I have a ICOM 2200-H installed in my Cessna 150 airplane. I am a fish spotter in southern California for tuna. Thanks to Modz I was able to remove diode 11 and 13 to open up marine (tx and rx) channels and aviation (rx, only) in addition to the normal 2 meter band. In short, I can rx from 118 mhz to 174 mhz but can only tx from 137 mhz to 174 mhz. I wish to tx on 118-136 mhz, does anybody know what diodes to remove or what exactly to do with this ICOM 2200-H to make it happen. Sure hope you do and can share with me. Thanks.
johnatti
WG5966

[Shortwave]

johnatti, on 13 August 2009 - 05:14 AM, said:

First of all thanks for allowing me to join in. I have a ICOM 2200-H installed in my Cessna 150 airplane. I am a fish spotter in southern California for tuna. Thanks to Modz I was able to remove diode 11 and 13 to open up marine (tx and rx) channels and aviation (rx, only) in addition to the normal 2 meter band. In short, I can rx from 118 mhz to 174 mhz but can only tx from 137 mhz to 174 mhz. I wish to tx on 118-136 mhz, does anybody know what diodes to remove or what exactly to do with this ICOM 2200-H to make it happen. Sure hope you do and can share with me. Thanks.
johnatti
WG5966

Hi Johnatti, and welcome to the forum!

Most of the Amateur Band transceivers will not TX within the airband, no matter what you do to them. Although general coverage receive is possible, transmission within the airband is limited in nearly all TCVRs by the firmware. I guess they did this so as to stop 'idiots' getting hold of the sets and trying to get QSL cards from pilots hi hi. Also, although it is a fairly simple matter to receive AM signals, it takes a good deal of extra circuitry to actually transmit AM, and most ham sets only cover FM, CW and SSB modes.

I have only ever come across one ham transceiver so far that did TX within the airband, and that was a Yaesu VX-7. The problem was though that the mod to allow the radio to TX within the airband seems to cause the radio to run what appears to be some kind of development software still resident within the processor. Among other things, all of the menus are in Japanese (maybe Chinese), and many of the buttons have their functions changed (E.G. the "Moni" button becomes the "Function" button etc.)

I would say a better option is to obtain a dedicated, type approved airband transceiver.


Best 73, Mark.

[K3ROJ]

Hi Jonatti,
Try E-Bay to locate a used aviation transceiver. The wife and I needed a transceiver to take along during fishing trips in Upper Ontario only in the event we would have an emergency since we are both senoirs. We found a nice used ICOM radio for $150. Sudbury Aviation uses a float plane, usually a Dehaviland Beaver to take us in to Lake MacSmith for a weeks fishing trip and in the event something bad may happen, they seem to always have a plane in the air during the day. By using AA cells, it is easy to carry spare batteries along since we enjoy listening to them chatting on 121.8 MHz.