Digital Ham Comms and COMMSEC/OPSEC

I quickly looked at "mygmrs.com", nice website, I saw where the repeater frequencies were listed but not in pairs.
I built and licensed quite a few repeaters in the 450-470 Mhz band, (at that time the channel spacing was 25 Kc, but I saw the introduction of 25Kc channel spaced equipment capable of being programmed the new 12.5 channel spacing requirement and then eventually saw 6.25 channel spacing), but I digress. The UHF repeater pair spacing in the 450-470 Mhz band was 5 mhz, with the mobile transmitting on the high side and receiving on the low side. When the 800mhz conventional and trunking band came around those mobiles transmitted low and received high but I'm not sure why.
Anyway, what is the channel separation for repeater pairs in the GMRS band and do the mobiles transmit on the high side or the low side? Also, what is the maximum transmitter power output and can a for example a 3dbd gain antenna be used to double the effective radiated power, or is that an FCC no no just like speaking in riddles is? Anyone? Thanks.

 

K thanks BTP

 

MURS? Beartooth? There are private, (plane to plane and/or plane to ground), aircraft 2-way channels, are they FM or AM like standard aviation channels? Sorry for so many questions.

 

Ahh

I see. I do recall that using a marine radio on land is a no no along with using a CB on water.
I remember once upon a time, (I have a lot of once upon a times), riding around the city with an FCC tech in his tekky van, (this man whose name I won't mention was absolutely a good guy, not a jerk, very fair, very knowledgeable and very sensible). We weren't chasing down make believe radio, (aka CB), violations, we were looking for a powerful, 250 watt plus ERP, VHF paging transmitter, (remember beepers, everybody had em all you had to do was find a phone booth to respond, [remember phone booths])? Anyway, the transmitter had drifted off frequency and was crashing into adjacent channels disrupting their communications.

 

Oh I see okay thanks for the info. update. Just for the fun of it, here is a simple and clear list of FCC do's and don't regarding CB use; not sure how thorough it is. I don't see anywhere where water restrictions or permissions is even mentioned! FCC Rules and Regulations for CB Radio

 

Ok, first, as @sec_monkey noted.... DON'T BREAK THE LAW!
On that note, I think my thought got away from me a bit (it happens, I have so few of them that I am inexperienced in keeping them in check)
I know about the One Time Pads (and P.S. the Monkey Net White Paper was a fantastic read and quite inspiring) but the OTP is about encrypting the message, not the transmission medium. It seems out of place if I wanted to tell my buddy that we were going to take the next left at main street while we are in a caravan somewhere.
I guess my curiosity was, (legality aside as I know you would be in the wrong) I can see how the iDEN phones are the best choice for transmission encryption (and legal), but would 128bit encrypted digital 2m/440/FRS/GMRS radio be.... what?... like a close second? what other negatives are there other than not being spread spectrum/vulnerable to DF?
The radios are capable of more power/distance, but that brings a bigger footprint for you to be found.
You actually could transmit a digitally encrypted signal across an open (no tone squelch) analog repeater and it would keep the encrypting (as the analog repeater just boosts all the signals on the input frequency regardless of what they are)
I know a lot of military/law enforcement are using digitally encrypted radios that are very similar to the ham radio ones (tho 256 bit or better I would imagine)
I wonder if encryption is legal if you own/lease the frequency (like some businesses do).

Anyway, guess I just wanted to explore what other good options there might be that had some sort of privacy/encryption other than the iDEN phones that seem to be getting pricier and harder to find.

J-Woodsman

 

It's a good and sensible rule for safety. I remember once on a commercial flight, one of the passengers took their phone off of airplane mode. The air Marshall was on him like a flash. Cuffed him then instructed the pilot to drop below pressurization elevation where he was shoved out the door with a parachute on. The air Marshall closed the door and looked at us and quipped, "oops, forgot to pull the rip cord"! Didn't we laugh ....

 

I used to wire in ANI, (automatic Number Identification), boards into transmitters that would periodically transmit the call sign so the base and mobile users didn't have to sign off with it every time they were done talking. The FCC station identifier was transmitted using audible, analog tones.

I could probably talk to some of y'all if I ever got around to getting my ham license. I do enjoy RF and I know it with my eyes closed even though I've been away from it for twenty years.