Hans
Thank you so much for coming back to me so quickly.
I'm not aware of any differences or deficits in the 20-10m assembly or operating instructions.
These are really minor points. For example, there is only an inventory for the low band version (p.5 of the manual for rev. 5) and, e.g., the simulated response of the LPF only seem to be documented for the low band version. It is perfectly possible to build the high band version with the existing documentation, but debugging a transceiver that is malfunctioning is a bit more challenging (but again, totally possible). In fact one may just as well argue that I did not familiarize myself well enough to address problems on-site, or that this only shows because the low band version is documented particularly well...
The operating manual provides sample sweeps for all the bands
I'm super afraid to ask for those sample sweeps (where do I have to look?) but I guess I have to since failed to locate them when studying the operating manual. The only sample sweep I find is on p.28 of the 1.10 operating manual, and FWIW it looks quite different from those we observed. Furthermore, the documentation states that "ideally the peak of the response (line of yellow asterisks) should coincide with the center frequency of the band" which is not really the case for our sweeps. I understand that the BPF is shared with the 17 m band center frequency of the band, but it looks wrong still which prompted me to have a more detailed look at this.
All that said, I am attaching a screenshot of the 20 m sweep as reported by the software and, for comparison, a sweep done with a SpecAn connected to the antenna port (TG) and to the pins of the single-ended side of T2, with the wire of T2 that connects to the IC3 output removed. I did not enable the marker table unfortunately, but to me, this sweep is quite different from the one in the terminal screenshot. I understand that the are not directly comparable as T2, the commutator and the amplifiers are removed but I would not have expected that kind of difference still. These are measurements from the unit I have access to right now, but most units were similar to those reported in this forum thread and thus even worse... I also understand that the audio-level dB should be divided by 2 for comparison with those reported by the SpecAn, but even then, it doesn't really add up, the shape looks different and the SpecAn sweep is also confirmed by the remaining measurements outlined in my previous post...
I guess the best way forward for me would be to first understand whether my results are in line with what is to be expected or not. I'm happy for any advice on this!
Regards and thanks again
Matt
