Trials and Errors Issue 50: Power to the (POTA) People!

I can understand that some will use it for POTA, and that's all good. To me it seems excessive for lugging around and a bit counter to the challenge of POTA.
But what about safety, RF Exposure rules? It would be easy for someone to be in the near field of your Alpha antenna.
On the other hand, I think it will make a great compact amp / tuner for the home station powered by an inexpensive switching power supply.
We may see a flurry of Elecraft KPA500/KAT500's for sale.
One thing is not clear to me: Dave, DGJ--you mentioned 6W in 600W out= 20 dB. How will it get FCC Certified if it exceeds the 15 dB max gain requirement of Part 97.317 (2)?
Requires modification to get the high gain?
Thanks,
John,
N1AU

 

Thanks Len, I had no idea! I wonder if POTA excludes those hams from nailing the "highest number of activations from one park" award.

 

Hi Jim, I'm now using the LITE on my desktop and having a blast. Like you, I didn't need another major sucker of power out of my shack outlet. It's already stressed. I'm using the battery behind it and it's really providing a lot of use. Not as much an issue as I thought . . . in fact, no issues. There's a setting on the Amp to automatically tune when it goes to another band. While you can't press tune on the radio, it only takes a few seconds when you change band to send a carrier and Zap you are on the air, tuned and all. Dave, W7DGJ (PS - the negativity on the Facebook posts were at least partly my fault, as I really ramped up my enthusiasm when I posted. It made it sound like some kind of YouTuber clickbait. In actuality, all I was doing was alerting hams to something that was just certified by the FCC. To me, it is very exciting that there is a new generation of amps coming (started by this one) that are smaller, less heat issues, and very powerful. As LDMOS improve, future generations could mean that we have a linear amp to carry with us that's no bigger than a IC-705. We're not there yet, but I can see it coming and I'll put my money on Kenny Martinez).

 

Hi John, the published details of the certification (it's already certified I believe) show that the FCC has modified their position on LDMOS, as amp manufacturers like Expert already have amps that exceed the ratio you mention. The really amazing thing about this little amp is that it has a switch to move the exciter from a traditional transceiver and 35-40w into the amp, to a QRP rig like the IC-705 or others that puts out 5-10W. I got the "6 in and 600 out" figure by using my IC-7300 in the "low power exciter" mode set for 6% out. I know that it's at least CLOSE, but I'm not sure it's 6 w on the money. For example, the protections go on when I set the ICOM to 10% power (10w?) and have it in the low power mode. Then, I can't use it. But as with other Merc's, the protections come on and it's safe. So, I've been running it (with the IC-7300) at the 7 or 8 % out position and it's going great. You can't easily get a good tune with only 5w. But with 7 or 8, no issues. Dave W7DGJ

 

I think I'm just lazy. Forgot the days when you had to first tune your radio manually and then tune the amplifier. Everything is so simple now, especially if you have a tuned antenna. I don't even use the tuner most of the time.

 

There is no "highest number of activations from one park" award from POTA, if you are at the top of the list for a park under activations or QSOs made, or if you are the first one to activate a park, it is just your own bragging rights Glenn AE0Q

 

Ha ha, looks a little like this, right Glenn?

 

Yes, we do have some awesome radio-quiet WWFF / POTA sites in the Colorado mountains away from the city !!
The 15 miles of canyon road up to 8400 ft is a little twisty but you can hear an S1 signal These places with no noise really encourage having a blast on CW, a LOT !!

I drove slow one day and got a pic of every road sign going up the canyon, top left to lower right...

 

1. Activators may not attempt to activate from private property, even if the private property is adjacent to, or surrounded by, park property. This is Directly from the POTA web site. It doesn't count if you live within said park if you activate from home, since your home is private property.

 

Thanks for the clarification Bill! Dave, W7DGJ

 

Hello,

I'm a mobile-only operator and make it a point to park (legally) in secluded areas that do not draw unwanted attention or create a disturbance. I recall once activating a park from a parking lot that was near a summit. I stayed in the parking lot for my very first POTA activation and a friend hiked 1/2-mile up a path for a SOTA activation. My "footprint" was larger than his because a car is larger than someone sitting on a rock with a QRP rig (or was it 100W?). But his antenna was strung to two trees, which may have earned some frowns in the wrong place. I think my method is working fine since my car would still have been taking the same amount of space whether I operated from inside or unloaded a backpack to hike to the summit.

I've considered an amp for a long time, not specifically for POTA, but hadn't found one that fits what I want. The Mercury Lite looks like a good fit for me. Still, I cannot quite imagine doing an activation with 600 watts because I don't want to send a signal farther than I can hear. I would, however, use the amp as a hunter to increase my odds of being heard in a pile-up whether it's a POTA pile-up or a contest pile-up. I'd also use it as a "goodbye amp" to close a QSO if conditions were changing and it was time to move on.

I agree with the sentiment of this statement. IF the purpose of the refuge is listed above, then ANYTHING that disturbs wildlife should be prohibited, including speaking above a whisper... IF IF IF. The apparent exception shown above is the occasional killing of the refuge residents (hunting). I kid, of course, but the paragraph above gives validity to the idea that wildlife refuges and sanctuaries never should have been listed for POTA in the first place. The list of eligible parks has grown to a ridiculous degree!

The uncontrolled compliance distance for 10m at 600W through a dipole is <10 feet and shrinks to just over a foot at 80m. Those numbers may be even smaller for a mobile HF antenna. I watch for pedestrians near my car and pause transmissions until they've passed. I think my usual operating practices are not exposing anyone to extra hazards when QRO. The exception would be for myself when operating a digital mode above 7.300 MHz, which I will not do QRO.

73,

Scott

 

Hi Scott,

You are an excellent operator with high ethical standards. Thanks for being a part of our Amateur Radio Services, Dave W7DGJ

 

I would add that I really enjoyed Scott's QRZ profile page and anyone interested in mobile operating should check it out (KE4WMF). He's driving around in one of the nicest mobile stations I've ever seen. I'm still dreaming about getting a setup like yours!

Scott, we both have beautiful XYL's who help us on activations, so we have that in common! Dave, W7DGJ

 

Dave,

Thanks for your comments about my mobile setup. I usually have just the verticals mounted. The horizontals are for contests and exhibitions; though exhibitions are fewer in 2025. As for my XYL, she does NOT help me with activations. She has absolutely no interest in ham radio. I can barely get her to come to lunches with hams even when no radios are present. But she's supportive of MY ham radio pursuits, even the ones that take me out of town.

Funny thing about my QRZ profile photo: I had just finished constructing the new tower setup and was ready to leave for either Hamcation or RARSFest when I realized that I had forgotten to fasten the choke at the top of the tower. It would have just flapped in the wind if I had not seen it. I'm probably too heavy to stand on the rack and I was lamenting the thought of bringing down the tower just for a few zip ties (I have a quick tilt feature now). My wife came home from exercise class just as I was about to start removing bolts to tilt the tower. "Hey! How would you like to learn to use a zip tie?" Thankfully, she's tall enough to reach the top of the 6.5-ft tower. She climbed up and was a good sport about being stranded for a photo. See a 5-minute segment with her in one of my videos HERE.