Place behind a face-panel twinned to a Cobra 29.
Base Station for the 22nd Century!
Hours of entertainment!
Amaze friends & family!
(MFJ-784b Tunable DSP Filter)
.
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This piqued my interest...
- Thread starter Big Kahuna
- Start date
Place behind a face-panel twinned to a Cobra 29.
Base Station for the 22nd Century!
Hours of entertainment!
Amaze friends & family!
(MFJ-784b Tunable DSP Filter)
.
BJ radionut
Supporting Member and 6m addict
BJ radionut
Supporting Member and 6m addict
BJ radionut
Supporting Member and 6m addict
https://gi1mic.github.io/
The $19 DIY DSP audio filter
This is a low cost open source audio DSP filter for Radio Hams. It is released as a building block for anyone who wants to design or customize their own audio filters. It is different from commercial offerings because is can:
The $19 DIY DSP audio filter
This is a low cost open source audio DSP filter for Radio Hams. It is released as a building block for anyone who wants to design or customize their own audio filters. It is different from commercial offerings because is can:
- Act as multiple DSP filters based on hi pass, lo pass, band pass or band stop (filter points can be defined in Hz within the code)
- It uses voice messages to describe which filter has been selected
- It is a USB to CAT interface
- It emulates a USB sound card for receiving rig audio on a computer
- Performs Morse to voice decode and Morse to USB serial decode
Thanks, you realize these are EXTERNAL - as in after you've got something you have to filter it out - right?
If you're going to pay that kind of money - you ain't doing it for CB only...
If you're going to pay that kind of money - you ain't doing it for CB only...
It sounds like this will be an internal not just DSP for the output audio. I'm guessing it will be similar to what is in some current ham radios, but that would be a big step for most CBs 
Who knows - maybe some engineer discovered something amazing and he just happens to work at the CB factory and next year we'll see it on all ham radios
Who knows - maybe some engineer discovered something amazing and he just happens to work at the CB factory and next year we'll see it on all ham radios
Here's his link - https://simonthewizard.com/2020/10/14/new-ae-6491-n-r-c-part-ii/
CB Is same thing. Not limited to export.
Cut coax & vehicle-noise then plug in a WMR DSP ClearSpeech Speaker.
I can then use the “useless” pre-amp on a KL203P effectively.
Durn it, BJ radionut, who is it gives out my card info and orders more stuff? At least it come to my address (feels like a clue).
That Bhi equip is tempting. Both the line attenuator (not linked) and the amp’d equalizer. Crank over one of these KES-5 speakers with rated power input and customized noise control.
The new truck stop parking lot competition.
That Bhi equip is tempting. Both the line attenuator (not linked) and the amp’d equalizer. Crank over one of these KES-5 speakers with rated power input and customized noise control.
The new truck stop parking lot competition.
When aligned properly, the optional "screw in" noise blanker board sold with my 1974 Tram D-201, works better than most NB circuits today. One of the best is the one used on the Uniden 8719 boards. It is more effective that any of my HF rigs, mostly because it only has to cover a narrow bandwidth.
When money is no object, you do what Motorola did on their top of the line, low band radios. You add an entire receiver along side of the main one and call it the "extender board" or channel. The second receiver has the same sensitivity as the first but lacks any IF filtering, so that it accepts a wide input bandwidth of several hundred Khz.
When this receiver extender is on, any impulse interference detected in the main receiver channel is instantly compared against what is being heard in the wideband receiver. If the impulse is detected across the wide band receiver and the narrow one simultaneously, a blanking signal is sent to the first sections of receiver amplification to blank out the interference. It can cope with anything from the smallest level of impulse noise, to the most aggressive noise that all other blankers fail to handle.
Until someone strong enough to bleed it keys up. Tram wimped and left the gain-control pin of the MC1350 blanker chip unused. Elecraft's K2 uses a startlingly-similar noise blanker circuit, but with its own AGC. Feeding into that same gain-control pin on the 1350 chip.
Incidentally, the Uniden noise blanker in the 8719 radios has its own AGC. And so does the blanker found in the RCI-made EPT36,69 and other pc boards.
I guess Tram didn't have room on the pc board.
73
Granted, the Tram noise blanker does suffer from strong adjacent signals but, part of that is due to the fact it took them until the D-201A came out before they got the receivers AGC to function properly on strong signals.
The D-201 had the AGC voltage wired back to both of the first two RF amplifiers and that left the first stage vulnerable to overload, as the second tried to compensate. They changed that in the D-201A and disconnected the second RF stage from the AGC loop and applied more aggressive AGC to the first RF amp only.
The change on the schematic is subtle enough that I missed it for decades, until one day I had my D-201A on the bench right next to the D-201. One of my locals kept forcing me to adjust the RF gain down to hear them clearly and then back up to hear the other station in the distance.
When I connected the D-201A, the AGC on that radio easily handled the strongest station and still heard the weak one fine. Its noise blanker also did not clip off the word peaks on the strongest station. That's when I went back to the schematic and spotted the AGC difference. As I recall it had something to do with a 100K resistor on the second tube and the modification made the D-201 a pleasure to operate with an extremely wide range of signal strengths on the frequency.