SteveShannon

I’m doing the same thing as Marc. I’m interested in something less expensive than the Bird, but better than the Farsomatic. ? Or if the Farsometer can be properly calibrated and relied upon I’d be interested. I have been looking at a couple of MFJ digital meters, but I don’t know if they’re much better than the Farsometer.

It might not hurt to ask a dealer if there’s a document like a TSB that specifies guidance for roof antenna mount location.

@axorlov, @marcspaz, and @Lscott Thank you guys! That was a truly interesting exchange on the signal strength meter and modulation types. It made me want to learn more. I knew that each S unit is 6 dB change, but I didn’t realize it was based on an absolute reference uV value, although in hindsight I should have.

Is there any way you can get that antenna outside of your attic and up in the air above your roof, if even just temporarily for testing? Are the houses around yours just as high as yours? What brand and model of antenna is it and what is its advertised gain?

My guess is that all professional repeaters have that ability, but I replied to this separately so someone with actual practical knowledge and experience can answer.

If CTCSS tones are used when transmitting, they can be scanned. But, there’s nothing that says you have to use the same tone as the “input tone” on the receiver side. But, someone within range of a legitimate user can still scan for the input tone and use that to gain access. I don’t know about scanning for DCS tones, but I assume it’s the same. In GMRS, there’s no foolproof way that I can think of to prevent unauthorized access and no radio is jam proof. You can change tones frequently, but that will inconvenience your legitimate users. There are a few forum posts by people who ended up taking their repeaters down because it just became too annoying.

I resemble that remark.

You’ll do great!

There’s no response to the station ID. It just is. There might be an app that needs no wiring, that simply listens. I don’t know. Study code? ?

Welcome!

Yes, exactly right!

That difference in power will make almost zero difference to range. I know that’s counterintuitive, but it’s true. Yes, I mean a cable and NMO mount that are permanently constructed and sealed to each other by a well respected manufacturer. Look at a place like DXEngineering or Ham Radio Output to see what companies like Larsen or Comet or even Midland offer.

I’m envious of the VX6! Please forgive me if I’m assuming took little knowledge or experience on your part. When listening for a repeater with the KG-935, you’ll hear it on two channels. One is a simplex channel and the other is a repeater channel. Both receive on the exact same frequency, but the repeater channel has a +5MHz offset for transmitting. So if you’re hearing a repeater on the simplex channel and try to reply, you’ll be transmitting on the wrong frequency for the repeater to hear. You might hear something on 462.550 MHz, but you’ll have to reply on 467.550 MHz in order for the repeater to receive your transmission. The repeater channels already have that offset programmed in. The other part is the use of tones. Almost all repeaters will have an “input tone” which allows them to reject any transmissions that are not accompanied by the same tone. The repeater then retransmits the transmissions that it hasn’t rejected, also using a tone, this time referred to as the “output tone.” Those tones can be actual tones, specified in Hz, almost always under 300 Hz, or digital codes. When they are actual tones they are usually referred to as CTCSS, but various companies refer to them differently. For example, Motorola refers to them as PL tones. The digital codes are usually referred to as DCS, but again there may be different terms applied. When they’re digital codes they sometimes have either an ‘N’ or an ‘I’ suffix, denoting Normal or Inverted. Typically, you must transmit using the correct input tone or the repeater will filter out your transmissions. However, when you receive, as long as you leave the receive tone unset, you will receive everything transmitted on that frequency. That’s good when you are just getting started because you can hear what’s going on. Again, I apologize if I’m assuming too little knowledge on your part.

I wouldn’t do an SO-239 to NMO fitting if it’s going to be exposed to the weather, unless you do an excellent job of weatherproofing. I would do an N fitting on the outside. They are a sealed fitting. And then I would order the right length of LMR 400 with a factory end on each end. Actually, I would just use a factory cable with an NMO fitting all sealed up on the end of it. I know it’s going to have more loss per 100’ than LMR400, but for a 13 or 15 foot cable it’s inconsequential.

Your heart is definitely in the right place! Alex (Axorlov) explained it well.

There are no standard CTCSS tones for a particular area and in general it’s a bad thing (very inconvenient) for radios to arrive with any tones set. However, there’s nothing wrong with using tones with simplex.

According to the FCC license search utility, 1221 GMRS licenses were granted in the past week, 5,165 in the last 30 days, 65,178 in the past year.

If you get moisture inside any coax you’ll have an issue, whether the shield and core are dissimilar metals or not. That has happened to people here on the forums and they end up lopping off the last couple feet or completely replacing the cable. But that’s not strictly the fault of LMR400 and I wouldn’t avoid LMR400 for that reason, especially if you already have it. I would take great care to waterproof the connections. In answer to your question about what to use, professional radio people would specify “hardline” and N connectors. If you have access to it, it’s measurably better in terms of losses and resistance to the elements, but it’s also more costly and less flexible. The link kits, as I’m sure you are aware, are unobtainable right now, but if you don’t mind paying a scalper high prices for a Raspberry Pi (or if you’re fortunate enough to already have a Raspberry Pi) you can assemble one yourself. [Edited to add: in other posts/threads of yours, it appears you have got all the parts, but were looking for help, so I’m confused. Did that not pan out?] I haven’t done it, but there are some threads on the forum. Take heart; Raspberry Pi models are reportedly expected this summer. We will see. Rpilocator.com is a good website to use to learn about availability. Here’s a link to a website that discusses building nodes: http://pascogmrs.us/video/how-to/ I have seen a video on YouTube that shows using a NanoVNA, using both port set up to measure insertion loss, to tune each side of a duplexer. I’ll see if I can find it. If I do, this is where I’ll place the link: The same person has another similar video:

I went and looked at the manual for the Rugged Radio GMR2. It's a nice looking radio. It looks like it only has the 30 preset channels. That's not the end of the world, but it makes it impossible to program multiple repeaters on the same frequency. Fortunately you can set custom, receive only channels. So, your repeater is on 462.675 MHz. That's already programmed into your radio as channel 20RP with the correct offset for transmit, so it will automatically transmit on 467.675 MHz. So, all you have to do is set the correct tone for transmit. If you're hearing the the repeater ID itself (and it certainly sounds like you are!) then you either have the tone cleared out or you are set to the correct tone. Based strictly on looking at the manual for five whole minutes, C-CDC, R-CDC, and T-CDC appear confusing. It appears, based on the third column, that the only entries for each are either "OFF", a CTCSS value, or a DCS value. I don't know if that means that both tones are set the same if you put a value in C-CDC, but that you can use different (so called "split tones") if you put different values into R-CDC and T-CDC. When you were hearing the ID, your receive value must have been correct. Setting them to 146.2 Hz might easily be why you no longer hear it. Try changing all three to "OFF" to see if you hear the Morse Code ID again. Then you can experiment with the R-CDC value to see what happens, but it would be horribly slow if you have to change it and wait another hour. Some radios have the ability to scan for a tone so you could determine what tone is being transmitted by the repeater. I didn't see that in the manual. What you can to though is set several of the receive only channels to that same frequency but with different tones to see which tone works. It's still slow. The best way is to find out from the owner what the tones are.

@WRWE511- Welcome! Drive closer and see if you can hit it. If you haven't already, clear out the receiver tone for your radio. That will allow you to hear all transmissions on the repeater frequency. Do you hear it when you just listen without any set tones?

Many repeaters have some "hang-time" programmed into them to continue transmitting for a short time after a person transmitting to the repeater stops transmitting. This is clearly audible and an indication that you have reached the repeater and that you're using the right tone.

Yes, 3-30 MHz is HF; 30-300 MHz is VHF; 300 MHz to 3000 MHz is UHF. GMRS uses channels in 462 and 467 MHz ranges. I’ve seen my satellite receiver fade out during heavy rains and snows. The higher the frequency the more moisture affects it. I haven’t range tested my GMRS radios in the woods. People use receiver tones to filter the signals that are reproduced. So for instance if there were several people using their radios and i didn’t want to hear them, but I wanted to hear from you, I would set a tone on my receiver and tell you the tone so you could set it for your transmitter. Then, when you transmit using that tone (tones are usually under 300 Hz) my receiver will reproduce your transmitted sounds after filtering out the tone you sent. But if I want to hear everything transmitted on that frequency all I have to do is remove my receive tone. Nothing will be filtered. It’s the same way with a repeater. The receiver half of the repeater only transfers audio to the transmitter that have the right tones when received.

How do you know I haven’t done a MARS-CAP mod on Oscar? ?

The ISS doesn’t do GMRS, but it does converse with ham radio operators. There’s absolutely no correlation between the range between two handy-talkies (HT) going north and the range to a repeater to the west. Different directions, different obstacles. Maybe, maybe not. The best predictor is to tune your handheld radio to the repeater output frequency, leaving tones completely turned off, and listen to see if you ever hear the repeater. If you never hear it you are probably out of range, or nobody is using it. You cannot use FRS radios on a repeater. Yes, at higher frequencies like UHF, foliage definitely absorbs signals. So can rain. So can snow.

That background helps. Some of the FRS channels are limited to only half a watt. Some use two watts. You probably will get better range with GMRS. Now, as far as seeking permission, first you have to get a GMRS license so you can get a full login here. That will allow you greater access to the repeater page. There are two different logins: one to mygmrs.com, and one to forums.mygmrs.com. You must be logged into mygmrs.com in order to request access to a repeater on the repeater pages and you must have a GMRS license, verified to the site via the FCC database, in order to have a login. Sometimes it takes a couple days for the verification process. Once you have your login you go to the repeater page and click on the repeater you want to know about. Then you can click on a link to request access.