Banuiesc ca nu te-ai uitat la link-ul pe care l-am postat mai sus in care este testat un IC-7400 vs SunSDR2 Pro:
https://www.youtube.com/watch?v=mwNDp4hfKRY
Pe un site german un posesor de SunSDR2 Pro reclama exact aceiasi problema, o sa caut linkul si-l postez aici. Mai exista si testele lui Leif SM5BSZ, o somitate in domeniul SDR:
https://www.youtube.com/watch?v=PwbEPFJ5fqw
- SM5BSZThe SunSDR2 Pro is mis-using the LTC2209 badly. The sampling clock or possibly noise on the ADC reference (or both) place the noise floor about 40 dB above the theoretical limit. That is with a strong signal present as you can see in the video. 40 dB - 10000 times in power is horrible. On 144 MHz one might expect 2 to 8 dB of this phenomenon which is equivalent to reciprocal mixing. It seems to me that Expert Electronics does not have anyone with some knowledge about ADCs. They claim that performance is limited by the LTC2209 which is utterly false. The Perseus which uses an older LTC chip of the same series with 14 bit only and half the sampling rate has much better performance - and it has been available for more than 10 years.
Alt test:
https://www.youtube.com/watch?v=3UsIpIbjeWg
Mentionez ca ma intereseaza parametrii strict pentru banda de 144MHz.
73!
PS Nu sunt, nu am fost si nu voi fi niciodata posesor de IC-7400