Unanswered Questions
253 questions with no upvoted or accepted answers
8
votes
1
answer
305
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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
4k
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
- 1
5
votes
0
answers
136
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 ...
- 17.8k
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
0
answers
231
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
76
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
339
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
137
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 ...
- 8,163
4
votes
0
answers
239
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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
0
answers
196
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 ...
- 8,163
3
votes
0
answers
100
views
Connecting up the vintage Morse Code Instructograph
As a teenager (1950's) I used an original Instructograph to learn Morse Code for my ham licenses, and had obtained a speed of up to about 30 wpm.
Now 70 years later, I have obtained both 3-post and 4-...
- 41
3
votes
0
answers
279
views
Strange interference - consistent series of beeps/chrips at frequencies 145-146 KHz apart
I'm new at Ham Radio, in fact still studying for Technician (so I can't transmit) but I purchased a used Icom IC-746, dipole antenna kit and most recently a Hexbeam antenna. The power supply is an ...
- 131
3
votes
0
answers
337
views
Tuning an L-band dish for receiving GOES signals
I've encountered some challenges with my ground station intended for receiving images from GOES satellites, and I'm seeking your expertise to troubleshoot the issue. Here are the system specifications:...
- 25k
3
votes
0
answers
857
views
How to disable STUN or KILL function in Chinese radios?
Many FM handheld and mobile radios employ "Stun sequence" and "Kill sequence" that can block the station TX or TX+RX functions after having received a specific DTMF code sequence ...
