While waiting on an "Your Anan-10E is ready" email I thought I'd test a claim on Apache Lab's website regarding SDR radios that use the AD9866 processor - ie, the Hermes Lite 2.
Apache Lab's comparative chart claims that the HL2 is not compliant on 10 meters. News to me...let's have a look.
[UPDATE: Harmonic content is within spec on all bands. I'll check IMD later in the year.]
I also wanted to test receiver sensitivity. I was asked about it in several emails after posting a video comparing receiver sensitivity of the QMX+, KX2 and FT-891.
I'll be the first to admit that receiver sensitivity is down the totem pole when it comes to receiver specs, topped by selectivity and dynamic range. Still, it's a useful test if only to verify the lack of a problem where one might be suspected.
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| Harmonics are well attenuated |
The Hermes Lite 2 (in my case) is run by Thetis software and the radio does not have a pre-amp - a useful thing to have on 10 and 12 meters. I didn't test those bands but will (either very soon or after an upcoming trip).
As mentioned in the video, I am (and remain) highly impressed with the HL2. Such a performer for the $.
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RIP Robert Redford.
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Hi John,
ReplyDeleteVarious testing of the Hermes-Lite 2 shows that it is FCC compliant on 10M:
https://github.com/softerhardware/Hermes-Lite2/wiki/Performance-Tests#transmit-power-amplifier
I am not sure what Apache Labs is referring to here and I have sent a clarification inquiry to them.
If I were to guess, a few prototypes of the original Hermes-Lite (not the Hermes-Lite 2) did have a spur in the 22-25 MHz range, but that was addressed by changing what features and modes we use on the AD9866. The Hermes-Lite 2 and all derivatives I know of (radioberry, square sdr) inherit these changes and no AD9866 based SDRs exhibit problems with 10M FCC compliance which I am aware of.
If you want to learn more, search for "spur" in this group and read some of the earliest posts from 2015-2016.
https://groups.google.com/g/hermes-lite/search?q=spur
On the web page which you share, Apache Labs does not mention some of the ways in which the HL2 is superior to the Anan-10E in my opinon:
The HL2 supports 4 slice receivers, not just 2. This is due to improvements in the FPGA gateware code which Anan-10E does not have.
The HL2 has alternate FPGA gateware which supports 10 slice receivers in a receive-only limited filter mode. This caters to those who wish to use the HL2 for skimming of all HF amateur bands.
The HL2 price point is considerably lower.
The HL2 is completely open source, even including the PCB design files and manufacturing flow.
73,
Steve
kf7o