Digital Mode Transceiver
High-band Phaser Kits - 15M and 10M
The new "Phaser-II" design is here for 15M and 10M bands!
We are pleased to start accepting orders for the "Phaser-II", the a high-band version of the Phaser. K1SWL has the Phaser-II running on 10M and 15M and we have a draft set of Instruction docs in final stage of editing for both. Kits start shipping on/before the end of September.
Dave reports that both 10M and 15M perform identically. He’s been performing measurements at 3.2 watts out, and this occurs at about 25% pot rotation on R10. They both 'max out' at a pretty clean 3.8 Watts.
Understand that we’re keeping the Rev C Phaser design in place for the current band coverage (80, 60, 40, 30, 20, and 17 meters), while this new Rev E design for "Phaser-II" approach is applicable for the higher frequency operation (15 and10 meters).
Pricing: Slight design changes and higher-frequency needs will drive up the Rev E price just a little: $70 ea.
Phaser-II for 15M or 10M
From Dave K1SWL ... "How I spent my Summer vacation"
(If the truth be told, I never enjoyed that first assignment of the new school year. Every summer was the same- holed up in the basement building ambitious homebrew projects that sometimes worked. But that's not important right now.)
I'm pleased to report that I have Phasers running on 10M and 15M to the tune of about 50 contacts each. As of this writing, I've received the final iteration of sample PCBs. Result: No cuts- no jumpers. Incredibly, PCB reference designators and documentation are in complete agreement. I've finished the assembly instructions for 10M and 15M. George has those in hand and is taking a well-earned breather before he works his document-magic .
The high-band version of the Phaser diverges from the rev C configuration with a beefed-up transmit strip. Perhaps most noticeably, U5 and U6 have been replaced with a pair of diode-ring mixers for improved carrier suppression. The rev C layout yielded less than a Watt out -not good enough. There's now a MMIC added to provide an additional 12 dB of gain. The PA device itself is different. It's now a MOSFET rated for 6W out at 175 MHz. I've reworked the output filtering to use a binocular core. The PA stage has also sprouted a bias trimmer to set idling current for the PA. The instructions for setting the bias are straightforward, thanks to readily-accessible test points on the board.
Both 10M and 15M perform identically. I've been performing measurements at 3.2 watts out, and this occurs at about 25% pot rotation on R10. Both versions 'max out' at 3.8 Watts. Beyond that point, signal quality deteriorates. With still-higher drive, the output actually falls off a little- the current-sense resistors are doing their job. This output power is limited by the turns ratio on the binocular core. It's pretty clean, too- attached images of the close-in and wideband spectra.
Oh, yeah- so how are they working out?
I've included a PSKreporter screen shot from 15M a week or so ago. I'm clearly being heard with the 40M doublet up 30-35 feet. So far, I've worked the US West coast, Europe and a dozen Caribbean and South American countries down to Paraguay and Peru. 10M isn't as well-populated- as you'd expect at this point in the sunspot cycle. Still- I'd make contacts on that band every day. 10M's propagation characteristics remind me of 6M- lots of contacts on this side of the Mississippi and one each with Europe and Africa so far.
We'll post more information when this version of the Phasers is ready to roll out. Thanks for your patience!
73- Dave Benson, K1SWL
Discussion List: Chat With The Designers ... https://groups.io/g/cwtd/topics
Questions? Email to George N2APB ...
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