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King transponders
- Thread starter kboyd59
- Start date
Norman CYYJ
Well Known Member
the KT76 is an older transponder with a completely different sized tray. The KT78A is a newer model which as been around for about 13 years or so. Both use a tube in the output. There are more discreet components in the KT76 than the 76A. Both operate the same but are old.
gmcjetpilot
Well Known Member
Good info, old tubes OK?
Thanks Norman, good info. I'd add kboyd59, if you're buying used, you can get good deals on tube transponder. Tubes can last decades. Tubes die from both use and age, but they can be long lived. If buying a used unit, if you can get a quick bench test and determine if its on freq, sensitive to interrogation and power output is acceptable. You can't do that on eBay, but I have had good luck w/ transponders I bought.
Thanks Norman, good info. I'd add kboyd59, if you're buying used, you can get good deals on tube transponder. Tubes can last decades. Tubes die from both use and age, but they can be long lived. If buying a used unit, if you can get a quick bench test and determine if its on freq, sensitive to interrogation and power output is acceptable. You can't do that on eBay, but I have had good luck w/ transponders I bought.
Norman CYYJ
Well Known Member
If you have to buy a new output tube the unit is not worth buying. The cost of a new tube is more than half the price installed than a new transponder. Stay away from the AT50 transponder. Lots of them out there cheap. They never were really any good. AT50A weren't much better.
