Newest Questions
4,999 questions
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How do you construct a 6:1 balun
I want to run 50 ohm coax from a tuner through the wall of my house to 300 ohm ladder line to an 80 meter dipole. How can I construct a 6:1 balun from 50 ohm coax?
- 19
3
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1
answer
156
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HF 49:1 toroid unun same ratio more windings
I've been looking for an answer, but no luck so far finding it. It's about windings, and it's effect on HF. 49:1 UNUN transformer. What will happen if we keep the ratio 49:1 and increase the number of ...
- 31
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63
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Dealing with alkaline cells "welded" into an alarm clock with weather radio [closed]
I have a half forgotten alarm clock with weather radio that has had the alkaline back up AA cells leak to a point that it effectively "welded" the plastic cover to replace them shut. It ...
- 379
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52
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What options do I have for a V/U 4 way 90 degree divider/combiner for satcom
I have a AV2011 satcom antenna that has a Merrimac QHF-2-.312GN power divider/combiner that's good for 225mhz to 400mhz and I'd to replace it with a wider bandwidth version buuut this series doesn't ...
3
votes
1
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93
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Measuring losses from reactive near-field interactions in simple antennas
Question:
How can we measure the total losses due to reactive near-field interactions relatively simply, without far-field strength tests or mapping out the entire near field distribution?
I've ...
- 2,610
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79
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VHF Handheld radio not charging after replacing battery
I recently replaced the battery of this SIMRAD HS35 handheld radio as it was dead. I bought a new that matched the description, replaced the old one and the radio works fine. The problem is that it no ...
1
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0
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105
views
Programming software for YINTAI YT-588 radio
I am looking for the programming software for the YINTAI YT-588 radio. Thanks. Marco
- 11
4
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1
answer
625
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Antenna - vertical & beam antenna transmit at the same time?
Is it possible to use a vertical antenna and a vertical polarized beam antenna at the same time?
I have a friend that lives about 7 miles away & I can talk to him on 220MHz FM just fine on a ...
- 41
1
vote
1
answer
102
views
EFHW With a 0.05 Wavelength Counterpoise - Use CP for Tuning?
If an EFHW antenna with a 49:1 transformer & a 0.05 wavelength counterpoise, can be considered an OCF Halfwave antenna, why can't I place a LC network somewhere in the counterpoise wire length to ...
- 51
0
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0
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52
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Loop Back test - GNU radio - USRP mini B200
I am new to working with radio and currently attempting to transmit a sinusoidal waveform from the transmitter directly to the receiver port. I found a flowchart online to set this up, but since I ...
1
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1
answer
69
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changing bandwidth from wide to narrow on my SW 3B transceiver
On my SW 3B I tend to scan the band (usually 40 metres) looking for a CQ call using the wide (2Khz "USB")) filter. Having tuned in I then change to the CW narrow filter (400 Hz "CW"...
- 11
4
votes
1
answer
140
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How to tell if a vacuum tube has gone bad?
Because it was $5 on my local classifieds, and I have a bit of a weakness for old junk, I bought myself a Heathkit HW-30 "Two-er". I've been going through the alignment procedure in the ...
- 161
2
votes
2
answers
125
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Correcting impedance at the feedpoint vs. at the radio
Recently I have been trying out some upgrades to my station. For all of 2024, I was using a Xiegu G90 (20W PEP) with 50' of RG-8 connecting it to a balun with a 5:1 transformer and a stainless steel ...
- 177
0
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1
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55
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CB Antenna (Jetfon AB/02 Base CB antenna) connection and grounding
I am trying to get into CB world and have couple of questions if some good soul could help out,
Radio is CRT 2000H and antenna is,
Jetfon AB/02 is a CB-27 base antenna with 3 radials.
FEATURES
Band: ...
- 103
1
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1
answer
58
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Distance to and type of objects affecting radiation pattern
Mostly interested in metallic / plastic objects.
do far field metallic objects influence radiation pattern ?
do plastic objetcs in the far / near / reactive fields influence the radiation pattern ?
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