As most of you know, off-grid ham radio is as much about reducing our current consumption, as it is about getting our signals out into the world. In a recent video, I discussed a change in station operating philosophy. I’ve switched over (gone back to) to QRP radios for their lower current consumption, versus their current hungry QRO desktop and mobile counterparts.
00:53 PA500 Background & Overview
02:33 New Portable Ham Radio Strategy
04:30 PA500 Detailed feature set
09:12 Field testing
14:32 Final Thoughts
When the decision was made to move over to QRP radios as opposed to more current hungry mobile radios, there was already an understanding that a QRP based station would need to be augmented at times, with an amplifier. There were several amplifiers to choose from. One from Elecraft KXPA100, the Xiegu XPA100, the Hobby PCB Hardrock-50, and an unknown player called DIY599 offering the PA500.
Each of these amplifiers has pros and cons but the only one which had specs purpose built for field communications, was the PA500. The other offerings were designed for desktop use with a QRP radio at home. That’s not what I was looking for! Sometimes I believe the engineers designing these other amplifiers, don’t understand the needs or goals of the field radio operator. Nevertheless, here we are.
Ultimately I settled on the PA500 from DIY599. Here’s some context behind that decision. The Elecraft, Hardrock50 and Xiegu amplifiers are all quite large for field communications. Their size and weight make them perfect for operating a QRP radio at home, but a complete failure when it comes to deployment in the field. Moreover, the current consumption of these amps while idling was unacceptable. For the field radio operator trying to gain an edge without the cost of higher current consumption on receive, the amplifier with the lowest current consumption on RX would be the winner. In part, that’s why the PA500 was chosen.
Version 2.0 of the PA500 consumes about 50ma on receive. That’s an acceptable insertion loss when operating portable with radios like the Lab599 TX-500, Elecraft KXx, Icom IC-705, Xiegu X5105 or Yaesu FT-81x. These rigs all have ridiculously low current consumption, compared to the Yaesu FT-891 or Icom IC-7300 for example. When we are trying to power our Communications gear off grid, we want to measure our current consumption on receive in milliamps not amps.
FCC Approval – Update from the Deck.
The FCC compliance measurements are done and we met all the FCC requirements.
Estimated start of delivery to US customers on waitlist will be around end of august.
the following features are already implemented or in progress
✔ frequency measurement capability – done
✔ power measurement capability – done
✔ no amplification between 26-28MHz – done
✔ automatic band-filter selection based on measured frequency – done
✔ overdrive shutdown – done
— digital temperature reading of the system, with automatic high temperature shutdown option – in progress (SW will implement soon)
The best place for up-to-date information about the PA500 amplifier is there groups.io page: https://groups.io/g/diy599 here you can get all of your questions answered, and get the latest up-to-date and accurate information about PA500 amplifier.