Skip to main content
6 votes
Accepted

Where can one get a "listed" SO-239 lightning arrester?

The NEC defines "listed" as: Listed. Equipment, materials, or services included in a list published by an organization that is acceptable to the authority having jurisdiction and concerned ...
Phil Frost - W8II's user avatar
6 votes
Accepted

Recommended way to analyze spectrum output of a high-power amplifier?

Professional-level dummy loads generally have a "sampling" port that provides a reduced level signal for analysis. You should be able to create something similar.
Dave Tweed N3AOA's user avatar
4 votes

Are cold temperatures harmful for ham radio equipment?

The other answers do a good job of covering the theoretical risks and the manufacturers' recommendations. I wouldn't think that you would bump into those limits in a garage in Portland, Oregon. As a ...
rclocher3's user avatar
  • 9,242
4 votes

Do lightning rods attract or do they help prevent lightning?

These ideas have been around for centuries as lightning dissipation theory and lightning diversion theory. Notably, Benjamin Franklin was an early proponent of lightning dissipation theory. He noticed ...
Phil Frost - W8II's user avatar
4 votes

Where can one get a "listed" SO-239 lightning arrester?

If the problem is only that “SO-239 connectors” and “listed” can't be found together but can be found separately, then you should consider using a different connector — SO-239/PL-259/“UHF” is an old ...
Kevin Reid AG6YO's user avatar
  • 24.7k
3 votes

Antenna grounding / bonding in relation to my AC service (with pictures)

Grounding is not something where there is a single answer. First, you should read up on the topic. I found a book entitled "Grounding and Bonding for the Radio Amateur" by ...
Hogstrom's user avatar
  • 187
3 votes

What steps to take to secure for G2 geomagnetic storm?

Nothing. A G2 storm is a common event; according to NOAA data it happens an average of 600 times per 11-year sunspot cycle. It won't hurt your radio, but it might make HF communication a little more ...
hobbs - KC2G's user avatar
  • 12.5k
3 votes

How can I protect equipment against a lightning strike?

What you need to do is follow the requirements of the National Electrical Code (assuming USA). This article covers it well. (ps. Failure to comply with NEC 810 is the #1 reason ham radio operators in ...
user2104506's user avatar
3 votes
Accepted

Setting up an Outdoor Antenna

Antennas meant to be permanently installed are designed to withstand the elements. A proper installation would definitely not require an enclosure around the antenna. Pay attention to rated wind ...
Nat Mote's user avatar
  • 260
3 votes

Are cold temperatures harmful for ham radio equipment?

I have had a Yaesu FT890 stored in an unheated shed in Saskatchewan for 15 years. Just recently dusted it off, and it fired up just fine. It gets to -40C here for weeks at a time in winter. YMMV of ...
Michael Nash's user avatar
3 votes
Accepted

Are cold temperatures harmful for ham radio equipment?

Amateur radio equipment is not greatly different from electronics in general. Some items might be unusually chunky and robust (e.g. a manual HF antenna tuner is a box full of metal shapes and ...
Kevin Reid AG6YO's user avatar
  • 24.7k
3 votes

Recommended way to analyze spectrum output of a high-power amplifier?

As answers already posted show, there are a variety of solutions to this problem. But, a very simple one is an old timer ham radio operator's "trick". Popular back in the late 1950s and 1960s as "...
K7PEH's user avatar
  • 3,008
2 votes

Recommended way to analyze spectrum output of a high-power amplifier?

As Dave Tweed says, professionals have equipment for exactly this. But since you are asking I bet you don't have that equipment. If you just want something on the cheap, transmit into a dummy load at ...
Phil Frost - W8II's user avatar
2 votes

DIY lightning arrestor - gap size?

Get a two terminal GDT and call it a day, use very short low inductance leads to attach it between the center conductor and earth ground. GDT (Gas Discharge Tube), Bourns make them, Digikey or Mouser ...
Bumbal's user avatar
  • 21
2 votes

Are cold temperatures harmful for ham radio equipment?

I think Kevin and Brian covered the important aspects, and these are the failure modes I'd expect to. Aside from the battery damage, nothing too dramatic. It's unlikely your electrolytic caps freeze,...
Marcus Müller's user avatar
2 votes

Can Yaesu FT-65 be charged from a 12 VDC automotive accessory outlet?

The battery inside the radio is almost certainly a lithium-ion type (one to three cells, most likely one or two), which requires the device to manage its charge (for safety, as well as for battery ...
Zeiss Ikon's user avatar
  • 4,107
2 votes
Accepted

How effectively do modern transmitters protect against high SWR?

I believe the answer currently is: yes it matters less, but it still matters. Variables include 1) the mode of operation and 2) the speed of the foldback circuit in the radio that provides the trigger ...
webmarc's user avatar
  • 4,241
2 votes

What are these antennas?

A possibility for their use is suggested by the small "globes" at the free ends of the conductors in the 2nd photo. If this array of conductors was intended for lightning protection, they ...
Richard Fry's user avatar
  • 2,922
2 votes

Antenna grounding / bonding in relation to my AC service (with pictures)

Ideally answer posts should address the entire question post, but the question post posed many questions, so I choose to answer just two of those questions. Yes, the NEC (National Electric Code, the ...
rclocher3's user avatar
  • 9,242
1 vote
Accepted

How do you protect your radio when testing custom RF circuits at ~100W?

(Without any guarantees from me) the radio is probably fully protected against high SWR. I've certainly abused my radio from time to time, changing bands and transmitting where there's no antenna, etc....
tomnexus's user avatar
  • 11.4k
1 vote

Antenna grounding / bonding in relation to my AC service (with pictures)

Put up your antenna, run your coax, put the lightning arrestor where the coax enters the house. Ground the lightning arrestor to its own ground rod. Bond that ground rod to your primary grounding ...
hobbs - KC2G's user avatar
  • 12.5k
1 vote

Antenna grounding / bonding in relation to my AC service (with pictures)

I think I missed the original focus of your question because it was so long. You do not want to bond to the neutral wire in your house. You want to bond directly to the ground rod or water pipes or ...
user10489's user avatar
  • 6,485
1 vote

What are these antennas?

Those are not antennas, but intended to be lightning dissipators. Basically, they are a type of lightning rod. A lightning rod or lightning conductor (UK) is a metal rod mounted on a structure and ...
Mike Waters's user avatar
  • 8,071
1 vote

Setting up an Outdoor Antenna

If you are doing VHF and UHF a simple antenna like a J pole can easily be made or if your prefer purchased. I have also liked making my own antennas. For HF frequencies a dipole is also easily made ...
Jim's user avatar
  • 1,778
1 vote

Do lightning rods attract or do they help prevent lightning?

As with most argued questions like this, there is some truth to both sides. Lightning rods can dissipate small charges if they have sharp tips, but when that doesn't work, their real purpose is to ...
user10489's user avatar
  • 6,485
1 vote

Are cold temperatures harmful for ham radio equipment?

The semiconductors which comprise the bulk of components in all modern ham gear are rated to operate over at least the "commercial" temperature range whose low end is 0C / 32F. Since most active and ...
Brian K1LI's user avatar
  • 7,878

Only top scored, non community-wiki answers of a minimum length are eligible