John:
The UHFSDR uses an "A" speed range(up to 1.4GHz) and LVPECL interface Si570. On fundamental the UHFSDR works up to 700 MHz. It has been used at 3 GHz utilizing the 5th harmonic. If you used the newer Si564(available at Digikey) you could go to 1.5 GHz on the fundamental.
Dave - WB6DHW
toggle quoted message
Show quoted text
On 7/28/2022 6:23 AM, John KC9OJV via groups.io wrote:
Ben,
Doesn't the UHFSDR use an even more exotic Si570? Additionally it need bandpass filters, LPFs and an upgraded computer interface. I think the bones are solid but these issues are hurtles to jump.
JohnKC9OJV
On Thursday, July 28, 2022 at 08:12:06 AM CDT, Dave Sublette <k4to.dave@...> wrote:
Ben,
I'm not sure I understand the 2M SDR issue.? I have the Ensemble II/VHF
built for 2M.? It is a direct receive unit.? I used it as an IF for my
2,3,5,and 10 GHz transverters.? It performed well, but needed an LNA ahead
of it.? It was fully as sensitive as the DEMI 2M transverter.? I don't know
how it would perform in a crowded band, such as they experience on the East
Coast during the VHF contests, but sensitivity should not be a problem.
Most serious VHF operators have a mast mounted LNA at the antenna anyway.
73,
Dave, K4TO
On Thu, Jul 28, 2022 at 8:42 AM Ben Cherry <satman39@...> wrote:
I agree, The Si570 can be finicy, and is quite pricey. It can also be hard
to source reliably.
BUT--- is there an alternate part that is as accurate?
I have some ideas for an FPGA using a softcare processor to replace the
TINY, and some fancy clock manipulations, possibly tieing a gpsdo into it.
? But that will be a project for the distant future.
As for the 2M sdr, I am hoping to avoid the transverter or mixer route.
One possibility is in the? UHFSDR by WB6DHW.
Thoughts?
Ben AD8AW
.
