SteveShannon

Even moisture in the air causes attenuation of UHF signals.

I agree. That is more accurate. It’s almost certain that the repeater has a higher and better antenna and possibly even a better receiver, but it’s much easier to physically find the repeater, which has a chance of eventually putting you within range of someone who is transmitting, than it is to find *someone who is transmitting* without approaching the repeater. Gotta start somewhere.

Probably a silly question, but is the repeater transmitting in narrowband? That will make the audio much lower.

Don’t feel bad. Lots of people like to do a data dump when asked a question (myself included!) Let me see if I can avoid over complicating it. I’m only going to concentrate on CTCSS tones. These tones just work as a way to avoid audibly hearing (in the case of a simple radio user) or retransmitting (in the case of a repeater) a received signal. If you transmit with a tone of 87.5 Hz, that tone is added to your audio. If I set my receive tone to 87.5 Hz, my receiver will allow your audio to be reproduced by my speaker, after filtering out the low frequency 87.5 Hz tone. My receiver receives other transmissions but doesn’t audibly reproduce them unless they contain the correct tone. If I want to hear everything I just remove the receive tones and it’ll audibly reproduce everything. Similarly repeater owners program their repeaters to listen for one specific tone. That’s the uplink tone, “up” meaning transmissions to the repeater, “down” meaning transmissions from the repeater to others. Any transmissions on the same uplink channel which don’t include that specific tone will be ignored and not retransmitted by the repeater. The repeater operator can limit who knows what the uplink tone is in order to reduce what the repeater retransmits. That’s about the only access control a repeater operator has in GMRS. Many repeaters also use a downlink tone. That is simply to provide a convenient way for people to hear the repeater transmissions without hearing other transmissions on that channel. There could be casual users who are simply using the same channel as the repeater transmits upon. Repeater users may not want to hear their chatter. In most cases the repeater operator uses the same downlink tone as the uplink tone. When someone chooses a different receive tone than the tone used for transmit, that’s called a split tone. Honestly, I’m not convinced it accomplishes much. It really doesn’t limit who can use a repeater as others have claimed, because a person can simply clear out the CTCSS receive tone and hear everything that’s transmitted. The only legal way to limit who can use a GMRS repeater is to try and keep people from learning the uplink tone. Because there’s a limited number of tones and because they can can be guessed or easily scanned if you’re near the repeater, that’s only a temporary limitation.

I’ve tested it and it seems like it works. A friend got a Wouxun KG-805G and it doesn’t appear to have the ability to scan for CTCSS. Someday I’d love to try one of those Motorola radios some of you have, but for now I’m pretty happy with my Garmin Rino.

Divide watts by volts to get amps. An advertisement for the Jackery 240 mentions 14.4 volts, so divide 130 watts by 14.4 volts and you get a little more than 9 amps.

A person could probably make something using one of the wideband SDR receivers, which are not filtered to remove sub tones. A software filter to remove everything above 300 Hz would allow you to see just the sub tone, which could even be fed into a multimeter with a frequency setting. Of course a cheap uv5r has the ability to scan for privacy tones so maybe that’s the easiest.

I’ve read that the audio coming out of a radio that’s designed for tones has already had the low frequency tones filtered out so that probably wouldn’t work. Here’s the article on Wikipedia: https://en.m.wikipedia.org/wiki/Continuous_Tone-Coded_Squelch_System It says: “In a communications receiver designed for CTCSS, a high-pass audio filter is supposed to block CTCSS tones (below 300 Hz) so they are not heard in the speaker. Since audio curves vary from one receiver to another, some radios may pass an audible level of the CTCSS tone to the speaker.”

I’m glad you got that my description was over the top; it was meant to be. As you pointed out a properly grounded system with a quality lightning arrester will greatly weaken the energy delivery. I think it’s fine to disconnect the coax also. That’s also why a grounded coax switch is better than a loose coax end inside a glass jar. Of course disconnecting on the antenna end is even better, but may be more challenging.

Disconnected outside the house and left on the ground with significant separation from the house will work. It’s not terrible. I just have a problem with the whole “put it in a glass jar” in the house. A spark that travels thousands of feet through the air won’t even blink once when it comes to a glass jar. I’d love to see that tested at a lightning lab! ?️ Ionized metal, vaporized cable dielectric, and air plus explosively expanding plasma in a glass container. What could go wrong? ?

The thing is there are literally tens of thousands of communication sites that rely on high quality lightning arresters and and grounding systems with all grounds bonded. They ride through massive lightning storms. Not one of them relies on someone disconnecting a chunk of coax and placing it in a jar. A direct strike certainly introduces some uncertainty, but forcing the lightning to take an unknown path by disconnecting a conductor and placing it in a glass container rather than providing a path to ground is worse. It’s voodoo engineering and we shouldn’t perpetuate such ideas. This document has lots of information (chapter 4 I believe) and also lists many other references. https://www.blm.gov/sites/blm.gov/files/Lands_ROW_Motorola_R56_2005_manual.pdf An even more succinct one is the document I linked earlier in the thread, but this one is the most comprehensive I’ve found yet, establishing minimum distances between the antenna tower and any radio buildings, showing how to protect antennas mounted laterally on towers with lightning rods, and many other situations.

Keep in mind that the grounded coax switch ii recommended was already secondary to a good lightning arrester. Paths to ground before entering the house in the first place provides more protection than a glass jar, which I believe is more myth than fact. Pretty sure NEC and ARRL don’t make such recommendations.

There used to be a machine gun range that let people bring in computers as targets.

We were pretty boring! But we had a NERC requirement that we had to comply with so we degaussed them and logged it.

I had to laugh when an acquaintance of mine said, “What’s next, being able to fog a mirror gets you an Extra Class?”

We used an industrial degausser.

When I got to the payment page it wouldn’t appear correctly. I called the toll free number on the ULS site and a nice lady there was very unsurprised. Apparently that happens a lot. She led me to another page where I could pay and it worked very well.

I don’t think you’ll ever notice the loss from 40w to 28w. Your antenna height will more than compensate. Just a couple more things about lightning protection. Proper grounding puts everything at the same ground potential. That allows the soil to absorb any voltage that would be conducted on the shield rather than following the shield into your home and equipment. But without a lightning protector on the center conductor of the coax which must be connected to the ground system, the high voltages associated with static electricity or a lightning strike to your actual antenna have a straight shot into whatever is connected to the coax, including your repeater. Even a temporary installation should have a good ground and lightning arrester. In your instance I believe the lightning arrester would be right at the soil level where your antenna coax enters your radio shack and tied into the ground system for the radio shack, which is also bonded to the utility service ground. Inside your house I would use an antenna switch that opens up the connection from the incoming coax and connects the incoming coax center connector directly to ground. I have read good things about Alpha Delta lightning protection. I’m a new ham and just learning what’s necessary and available for amateur radio. My background is electric utilities and utility SCADA where grounding systems were literally the foundation upon which everything was built. https://www.alphadeltaradio.com

Edmo01 Congratulations! Although I’ve been somewhat interested my whole life, I just finally did my ham exams this month (Jan 6). I also used HamStudy, including buying the app for my phone and tablet. It made studying really fun and enabled me to pass all three tests. The older hams there were not much older than me and were very friendly. I think I’ll enjoy the hobby and I wish you many years of enjoyment as well.

Tyke, Perhaps I misunderstood. Will you be running any physical connections between the house and the tower? Coax, power, Ethernet cable, cables for monitoring other conditions (you might have mentioned some kind of telemetry)? If not, then you don’t need to worry about it. I thought you were proposing disconnecting the coax from the house whenever you anticipate lightning. I apologize if I misunderstood. If there’s never going to be a physical connection, then disregard what I said.

Nobody suggested that you shouldn’t disconnect your coax, but if you don’t tie your grounds together with #6 or #4 copper your coax will tie them together. Your radio will have one ground potential and it’s possible your antenna will have a different one. Just be sure and install an arrester as mandated by NEC.

How is the power and ground wired to your radio?

Here’s an article, written in English rather than “regulish”, on correct grounding for antenna systems. You really ought to reconsider your grounding. https://reeve.com/Documents/Articles Papers/Reeve_AntennaSystemGroundingRequirements.pdf

All of the city of Seattle and north of it are above Line A. That may be about 4 million people or more. Metro Detroit is also above it. That's another 4 million. Lansing Michigan is also. It's metro population is about half a million. So, probably 10 million people live above Line A. That's probably 100 GMRS licenses. ? Edited to add more cities that lie above Line A: Ann Arbor, MI, Flint, MI, Duluth, MN, Cleveland, OH, Toledo, OH, Erie, PA, Syracuse, NY, Buffalo, NY, and Rochester, NY.

That’s great information. I am not terribly interested in contesting (I think - I’m still a very new ham) but I am interested in things that lend themselves to medium distance communications and possibly someday long distance. I would like your post, but I’ve exceeded my like limit and the like clock doesn’t reset until later today, apparently.