Unanswered Questions
253 questions with no upvoted or accepted answers
8
votes
1
answer
444
views
Choice of PCB coil design for filter inductor at ca 20 to 400 MHz, 5 W
Looking at the diplexer schematic from this nice question,
I realized this can completely be done in PCB-formed elements (minus the connectors). (As a kind of counter-action to the original question'...
CommunityBot
- 1
6
votes
0
answers
5k
views
Simple AM receiver with gnuradio / RTL-SDR
EDIT: I have succeeded in getting the AM receiver to work, by replacing the AM Demod block with a Complex To Mag, and a Band Pass filter (this is noted as an alternative in the AM Demod docs).
...
CommunityBot
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5
votes
0
answers
181
views
Are there any stations other than W1AW that fall under 47 CFR 97.113(a)(3)(iv)?
47 CFR 97.113(a)(3) normally prohibits amateurs from transmitting
[c]ommunications in which the station licensee or control operator has a pecuniary interest, including communications on behalf of an ...
- 18.5k
5
votes
0
answers
1k
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What is an expected IF level of SA612?
I tried to use SA612 as a frequency mixer. Since it's a Gilbert cell, it has a high input impedance. Thus I added a pair of transformers as "Experimental Methods in RF Design" book suggests:
...
- 1
4
votes
1
answer
431
views
How can I control my FT-857 with CAT?
UPDATE: The problem I was having was just a loose cable, but I'm leaving this question up for any other 857 users who want to know how to configure the software.
I am trying to control my Yaesu FT-...
CommunityBot
- 1
4
votes
0
answers
126
views
"Fractal" Radials?
There are research and examples of "fractal antennas" where the radiator is in a "fractal-like" shape, mostly to save space. Those antennas often come with a penalty in gain (...
- 4,331
4
votes
0
answers
350
views
APRS-IS filter by message sender
I'm using KD0NKS' JS-based APRS-IS demo to query APRS-IS servers directly. I'm trying to only receive messages sent from my callsign using server-side filters.
I've tried using a budlist filter (b/), ...
- 41
4
votes
0
answers
93
views
Optimizing Half-Duplex Sequencing: Consolidating RF and Power Connections with Bias-T and VOX
I've successfully implemented a half-duplex sequencing mechanism, which I've illustrated below. The outdoor components are represented in green. In my current setup, I utilize a PLC to control both an ...
4
votes
0
answers
447
views
GNU Radio and OsmoSDR AGC for Hack RF
I am trying to construct an automatic gain controller for my HackRF when in receive mode. I am using the gr-osmosdr block in GNU Radio to interface with the HackRF. I am then running my received I and ...
4
votes
0
answers
174
views
Checklist for QRO remote setup
In a few weeks I'm hoping to set up a solid state linear amplifier at a remote shack that I've set up at the house of a friend who lives in a rural area. I've been connecting to this shack remotely ...
- 8,320
4
votes
0
answers
260
views
HackRF One and IoT overloaded?
I'm transmitting Z-Wave frames using HackRF One in loop, one frame every second. Has anyone clue why are some frames not transmitted? You can see several too long gaps between frames on Waterfall (...
- 1
4
votes
0
answers
1k
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OFDM spectrum, HACKRF, and GNUradio companion
I am trying to analyze the spectrum of wifi spectrum.
I getting a good OFDM spectrum with my HackRF at 2.412 GHz (from my first QTGUI Sink).
But I get nothing out of OFDM Receiver. I was wondering ...
- 419
3
votes
1
answer
245
views
Clearest way to measure ferrite choke effectiveness?
I have some snap-on ferrite chokes that are supposed to cut down on EMI, and I was wondering if there was any relatively direct way to measure — on the bench — whether they are effective or not. Is ...
CommunityBot
- 1
3
votes
0
answers
473
views
What's the minimal recommended power for EME on 2.4 Ghz?
As a follow-up to this question and the tremendous increase in availability of 10 and 2.4 Ghz equipment because of the QO100 satellite, I was wondering what the minimal recommended power on 2.4 Ghz is ...
- 8,320
3
votes
0
answers
237
views
Did CQ's WPX and WAZ awards die with the magazine?
As we know, CQ Magazine has breathed its last.
However, the CQ WPX and WAZ awards still show up in ARRL's LOTW.
Are those awards programs actually still alive? (I mean they certainly could be -- ...
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