When I run digital modes with my FT-817, I keep an eye on the output power with a little cheap wattmeter from MFJ. I’ve consistently noticed when I first start operating that I’m pushing exactly 5 watts out of the rig at high power. That’s good, because this is a 5 watt radio…
But after about 10 minutes of operation, I consistently see that power level drop to half. Increasing the audio input into the rig from the Signalink will bring the power close to 5 watts out again, but at the cost of overdriving the ALC, which is going to screw up my digital mode work. Since this has always happened consistently after operating for several minutes, I figured it had something to do with the radio warming up and creating some sort of instability.
I’ve sort of accepted this as a quirk of the 817 on “key-down” modes, but I’m getting aggravated with it, because I want my watts back. It’s getting harder and harder to make QSOs with these gators running 45+ watts on the JT65 frequencies. I need all the power I can squeeze out of this radio.
After last night’s disappointing run, in which I completed exactly ZERO digital contacts in attempts on multiple bands, I decided it was time to do some research. I came across this thread, that suggests the problem can be fixed with a menu setting.
The issue apparently stems from the 817 aggressively applying “Overcurrent Protection” when the radio reaches operating temperature. The poster goes on to detail a procedure to adjust the protection in such a way as to allow the radio to deliver optimum power while still protecting its innards from overheating. Of course, tinkering with hidden service menus can screw up a rig (Service menu docs are available here), so I’ll need to investigate this procedure further before I proceed.
Of course, there is debate on whether the 817 should even use the full 5 watts for 100% duty modes like PSK and JT… I have good success with 2.5 watts sometimes, but knowing I could increase the power a bit for difficult contacts would be helpful.