Lab Tests are interesting but there is no better test of a receiver's front-end than to use it on a good antenna at a BIG Multi-Multi Contest Station during a major contest.
The ALT-512 was designed and built in Bulgaria, so the logical thing to do was test it on-site at LZ9W during the 2018 CQWW DX CW Contest.
As seen in the photo above, LZ9W is a very BIG Multi-Multi Contest site.
It has won several big contest in the past. During a contest, at any one time there is a lot of RF in the air surrounding their site!
During the CW contest, a couple of OM took an ALT-512 on-site on Sunday afternoon, about 11:00 GMT. They connected the ALT-512 to a 40m monoband Yagi antenna, about 30m high. The ALT-512 was used to make a few contacts, and then it was compared to a second radio, an ICOM IC-7600.
At this time, LZ9W had 6 stations simultaneously on the air,
operating full legal power
in the CW portion of all 6 hf contest bands.
Theyoperated the ALT-512 in the SSB portion of the 40m band using just the antenna, and no external bandpass filters.
RESULTS: ALT-512 (+ External 300 Watt Amplifier)
During the QSO, the radio performed as it should.
Results: ICOM IC-7600 (100 Watts SSB)
The front-end of the ALT-512 is very Crunch-Proof.
There are very few other radios, regardless of price,
than can be used in this sort of environment without