Questions tagged [testing]

Techniques for testing the functionality of radios and other equipment. Do not use this tag for license examinations; use [license] instead.

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20 votes
2 answers
15k views

How to detect common-mode currents or “RF in the shack”?

Let's say we already know that if your antenna is not suitably constructed or connected then you can get current on the shield of your coaxial feed line which will flow through the shielding/grounding ...
Kevin Reid AG6YO's user avatar
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15 votes
3 answers
2k views

WWV, WWVH, and WWVL may be shut down. Are there any alternatives?

The US government is proposing to shut down the NIST standard time and frequency stations WWV, WWVH, and WWVB in Colorado and Hawaii. If that actually happens, are there any free or inexpensive ...
Mike Waters's user avatar
  • 7,958
10 votes
5 answers
2k views

How did hams manage to tune their antennas before VSWR meters?

In the early 20th century --back when the hobby was still new-- before VSWR meters and antenna analyzers were invented, how did radio operators know whether they were tuned for maximum power out? ...
Mike Waters's user avatar
  • 7,958
5 votes
3 answers
5k views

Are there any good, consistently receivable signals in the US for HF receiver testing?

Having built my first HF receiver, I'd like to know if I'll need to search around for transmissions that happen to be occurring, or if there are reasonably strong signals I can count on being present ...
Adam Davis's user avatar
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4 votes
1 answer
154 views

How do businesses develop and test amateur radio products in the US if you cannot be paid for amateur radio use?

Certainly there are companies in the US (like Kenwood) that develop HAM products that transmit. For development and QA they would likely need to test the product outside of a Faraday cage. How can ...
KJ7LNW's user avatar
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6 votes
4 answers
1k views

Testing for 'Bad' Coax

I have a lot of 'donated' coax that has been given to me with unknown provenance. I'm wondering what things I can do that can determine whether I keep it or send to the tip? Some of the things I have ...
Ben Short's user avatar
  • 163
3 votes
1 answer
165 views

How to fix SignaLink non-linearity problem?

I decided to check the linearity of my Yaesu FT-891 signal using an RF sampler and an oscilloscope. To generate two-tone (1550 Hz, 2150 Hz) signal I used Audacity. To connect the transceiver to the PC ...
Aleksander Alekseev - R2AUK's user avatar
3 votes
1 answer
244 views

Would a switched RF attenuator be (a)symmetric?

I picked up this 0-80 dB switched RF attenuator at a flea market, with no part number or other useful markings other than the knob settings. I've tested it and confirmed that it works, but there's one ...
Kevin Reid AG6YO's user avatar
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3 votes
2 answers
149 views

What safety procedures should be followed when developing and testing a high power amp?

I'm designing a 300W power amplifier using the MRF300AN from NXP targeting a center frequency of 146 MHz. Obviously I need to keep my fingers out of it and test into a dummy load, but generally ...
KJ7LNW's user avatar
  • 723
2 votes
1 answer
382 views

What is a "feed-through load" and how does it work?

While browsing some miscellaneous RF test equipment supplies I stumbled across a two-port component sold as a "feed-thru load". Take for example the Pasternak PE6026 (datasheet), which looks ...
natevw - AF7TB's user avatar
2 votes
2 answers
2k views

Simplest, smallest antenna for tuning WWV, WWVH?

I'd like to perform some simple receiver testing and calibration (mostly for frequency variance, not signal strength) and have been told WWV/WWVH transmissions can be found throughout most of the US. ...
Adam Davis's user avatar
  • 12.1k
1 vote
2 answers
499 views

Is there a proper way to connect multiple radios via coaxial cable so they can be tested without going over the air?

Let me state up front that I am not an RF engineer, but I do have a EE background. I'm working with a group that has a collection of radios, VHF and UHF (military) that is licensed to use a VHF and ...
AnAnonymousParty's user avatar