23-07-2024, 04:55 PM
Untuned loops are very poor and also can't be used for tx.
The wellbrrok is poor compared with any decent homemade tuned loop. Any loop needs designed for about 1:4 frequency range max and 1:3 is better..
The RSP series is about the cheapest decent SDR, but because it's not got RF tuning and is 14 bits, it's inferior to a 1970s to 1990s dual conversion superhet for 100 KHz to 30 MHz. A decent sound card can do SDR at VLF better. The RSP are immensely better than even the rarer 10 bit TV sticks (24 or 42 MHz to 1200 MHz and more a cheap spectrum display), but in absolute terms they are a basic budget model, not "very good" by professional standards, or compared to commercial main brand amateur gear.
I'd maybe have considered an RSP1B if I didn't have my FT817ND and only had the FT101ZD MkIII for HF. But I also have a VR500 and a VX5R and replaced the FT101ZD with the FTdx10 (a hybrid SDR with dual SDR, one for 1 MHz width spectrum display and the other 16 bit for Rx/TX, with an FPGA for the SDR.
The best use for the RSP1B on HF would be to drive it from the input (or output of 1st IF if RF on aerial is more than 75 MHz) to the 1st IF on an existing rig and then there is proper RF tuning, switchable pre-amps and attenuators, and coverage above half the sample rate without the doubtful downmixing by aliasing.. A 16 bit sound card with a filter is better for VLF and the coverage about about 75 MHz is relying on bandpass filters and downconversion by aliasing. That is indeed done on phone handsets / mobile modem / data links for 750 MHz to 6 GHz using ADI made ADCs that are clocked at 50 MHz to 200 MHz. I know someone who does the SW for those SDRs (on FPGAs for prototypes or low volume and ASIC for portable devices. ADI is 6 km up the road here and I know two people working there. They do also have PC based tools for development. The better systems are now 16 bit rather than 14 bit and some instead of two ADCs driven I & Q, used an array of psuedo-randomly connected ADCs to sample at 8 times the clock.
The wellbrrok is poor compared with any decent homemade tuned loop. Any loop needs designed for about 1:4 frequency range max and 1:3 is better..
The RSP series is about the cheapest decent SDR, but because it's not got RF tuning and is 14 bits, it's inferior to a 1970s to 1990s dual conversion superhet for 100 KHz to 30 MHz. A decent sound card can do SDR at VLF better. The RSP are immensely better than even the rarer 10 bit TV sticks (24 or 42 MHz to 1200 MHz and more a cheap spectrum display), but in absolute terms they are a basic budget model, not "very good" by professional standards, or compared to commercial main brand amateur gear.
I'd maybe have considered an RSP1B if I didn't have my FT817ND and only had the FT101ZD MkIII for HF. But I also have a VR500 and a VX5R and replaced the FT101ZD with the FTdx10 (a hybrid SDR with dual SDR, one for 1 MHz width spectrum display and the other 16 bit for Rx/TX, with an FPGA for the SDR.
The best use for the RSP1B on HF would be to drive it from the input (or output of 1st IF if RF on aerial is more than 75 MHz) to the 1st IF on an existing rig and then there is proper RF tuning, switchable pre-amps and attenuators, and coverage above half the sample rate without the doubtful downmixing by aliasing.. A 16 bit sound card with a filter is better for VLF and the coverage about about 75 MHz is relying on bandpass filters and downconversion by aliasing. That is indeed done on phone handsets / mobile modem / data links for 750 MHz to 6 GHz using ADI made ADCs that are clocked at 50 MHz to 200 MHz. I know someone who does the SW for those SDRs (on FPGAs for prototypes or low volume and ASIC for portable devices. ADI is 6 km up the road here and I know two people working there. They do also have PC based tools for development. The better systems are now 16 bit rather than 14 bit and some instead of two ADCs driven I & Q, used an array of psuedo-randomly connected ADCs to sample at 8 times the clock.
