Jones

Back in the old days, we used to have "CB Jamboree" events out here in the midwest that would bring folks in campers & RVs from across the nation.  Perhaps one of these days, (not soon due to Kung Flu) but one of these days someone could host a "GMRS Jamboree" for the same purpose.... get together for fun, food, and fellowship - and have a big swap meet to swap radios, antennas, parts, and bushel baskets of bull.. uh, chips.

I was going to tackle this project, and compile such a list. ...however, after researching radio and electronics related acronyms, shortcuts, and abbreviations for about 20 minutes, I realized that it was overwhelming, so the only one left for me to consider was OMG!. ...and I quit.  Will be happy to answer one-at-a-time as needed, just not publish 14,000 at once.

I think this group coined the term "CCR" to mean what it does here.
 
For 50 years before this forum, I, and many others used the term "CCR" to refer to a quartet of musicians:
Stu Cook, Doug "Cosmo" Clifford, and the Fogerty brothers, Tom and John.

I think a fundamental problem is that many of the more difficult acronyms are actually slang and the more common actual radio terms (SWR, LOS, etc.) can be looked up online. For example, the term CCR only appears once in the three lists posted by Lscott, and then it is defined as “Central Control Room.”
 
However, I do think the initial comment about newcomers to GMRS understanding acronyms is valid. So, I would suggest two things.
First, if you use an acronym in a post, note it’s meaning at the first reference. Example: GMRS (General Mobile Radio Service)...
And second, if you see a term you don’t understand, do as TomWRHZ479 did, ask.

Actually, I was suggesting that it be defined on first reference in any post, or at least the first time referenced in a thread.

Back in the old days, we used to have "CB Jamboree" events out here in the midwest that would bring folks in campers & RVs from across the nation.  Perhaps one of these days, (not soon due to Kung Flu) but one of these days someone could host a "GMRS Jamboree" for the same purpose.... get together for fun, food, and fellowship - and have a big swap meet to swap radios, antennas, parts, and bushel baskets of bull.. uh, chips.

Marc, I must add that I am a also very technical person, being a broadcast engineer, but that doughnut analogy of yours is spot on.  A flattened doughnut will spread its contents outward from the center point - just like a stacked vertical antenna array - no doubt about it.
 
Now... uh, where are those doughnuts?  In my world, 12 dB = one dozen doughnut balls. Mmmm.  I'll take those with RC Cola please.

I wish we all lived closer.  I would love to sit down and chat with many of you.  There is a lot of knowledge and experience in this group.  I would definitely bring some doughnuts.

Marc, I must add that I am a also very technical person, being a broadcast engineer, but that doughnut analogy of yours is spot on.  A flattened doughnut will spread its contents outward from the center point - just like a stacked vertical antenna array - no doubt about it.
 
Now... uh, where are those doughnuts?  In my world, 12 dB = one dozen doughnut balls. Mmmm.  I'll take those with RC Cola please.

Thanks for the writeup Marc, very good.   ..except I have to agree with Axorlov, a quarter-wave antenna has a gain FACTOR of one, not a gain of 1dB. 
 
A gain factor of one, is in fact, zero dBd, or 2.15 dBi.
 
An antenna that is rated for 3 dBd gain would have a gain factor of 2, thus a 10 Watt transmitter going into a 3dBd gain antenna would produce 20 Watts ERP. (effective radiated power)  Each 3 dB of gain represents a doubling of power. Each 3 dB of loss equals a halving of power.

Marc, I applaud the effort, but you've got the "gain" thing incorrect. Gain is a relative measure: something over the reference. And decibel is a logarithmic unit. "my antenna has 1db gain" translated to English means "intensity of the field created by my antenna is 1.26 times higher than the intensity of the field created by <what exactly???>".
0 dB = no gain over whatever reference you are using
1 dBi = 1 decibel over isotropic antenna ("i" is for isotropic)
1 dBd = 1 decibel over half-wave dipole ("d" is for dipole)
Half-wave dipole has 2.15 dBi gain, that is 2.15 dB over isotropic antenna, and the intensity field is shaped like doughnut
Quarter-wave monopole over ideal ground has 2.15 dBi gain, and the field is shaped like the upper half of the doughnut
 
1/2-wave and 1/4-wave antennas often called "no gain" or "unity gain" because they have 0 dBd gain (who might have thought...).
 
Manufacturers and resellers may specify dBd or dBi. When they just specify dB it is better to assume that dBi is stated.

That is likely due to capacitance coupling of the ground plane.   That is a mag-mount antenna, so the ground plane is not DC coupled at the base of the radiator.

That is likely due to capacitance coupling of the ground plane.   That is a mag-mount antenna, so the ground plane is not DC coupled at the base of the radiator.

True.  And the higher gain they are, the more narrow the bandwidth will be, and more difficult to tune.  There are no antennas that have enough bandwidth to be used from 420 MHz to 470 MHz without tuning, but the most bandwidth coverage is from quarter-wave antennas, which are about 6 inches long.  A quarter wave can cover from 433 to 468 with good results and fairly low SWR.  ...and watch out at ham fests and flea markets for quarter wave UHF antennas that seem too cheap.  I saw a guy once selling UHF quarter-wave NMO antennas for $1 each.  I measured one, and it was only 5-1/4 inches long.  Those are to cover 470-512MHz, and won't work for GMRS or ham.  If they are too long, you can grind them down. If they are too short,         .  .  .    _  _  _    .  _  .  .
 
Guys, if you are looking for a super high gain antenna for both Ham and GMRS use, just give it up.  There will be a compromise on one end, or the other.  If you must use just one antenna for both UHF ham and GMRS, then use a quarter wave tuned to 450.

True.  And the higher gain they are, the more narrow the bandwidth will be, and more difficult to tune.  There are no antennas that have enough bandwidth to be used from 420 MHz to 470 MHz without tuning, but the most bandwidth coverage is from quarter-wave antennas, which are about 6 inches long.  A quarter wave can cover from 433 to 468 with good results and fairly low SWR.  ...and watch out at ham fests and flea markets for quarter wave UHF antennas that seem too cheap.  I saw a guy once selling UHF quarter-wave NMO antennas for $1 each.  I measured one, and it was only 5-1/4 inches long.  Those are to cover 470-512MHz, and won't work for GMRS or ham.  If they are too long, you can grind them down. If they are too short,         .  .  .    _  _  _    .  _  .  .
 
Guys, if you are looking for a super high gain antenna for both Ham and GMRS use, just give it up.  There will be a compromise on one end, or the other.  If you must use just one antenna for both UHF ham and GMRS, then use a quarter wave tuned to 450.

I am glad that I am not the only one struggling with a TK-880! I purchased one from Ebay and I have not had any luck getting the KPG-49D software (ver. 4.20) to access the radio. When I turn it on it quickly displays VER: 1.5164 (Passport firmware?) then displays CH   1. I cannot get it into programming mode from the panel and the KPG-49D. I get an error message that says "Please check connection and communication port setting". The power switch, volume buttons and the monitor button work but nothing else. 
 
I have not found a way to do a hard reset or unlock the radio. It is a TK-880-1 Ver 2.0 according to the tag. Frustrating to say the least. Ham radios have been a piece of cake in comparison.

It's a "Snake Radio Custom". In my opinion, a clueless "screwdriver expert".  Keep in mind Marc, the SSB power control in these radios is useless and no longer functional when the ALC transistor has been clipped out for "Maximum Swing" or whatever.  ..and Jesse, If it were a clean 100, or even 500 Watts at 27 MHz, it would in no way harm the Motorola UHF front-end, however this thing with its un-filtered chinese-made amp slab is very likely going to be grossly dirty on the spectrum, so no promises.  The only thing I can promise you is that no oscilloscopes, or spectrum analyzers, or professional technicians were used in the tuning of this "Super" radio.
 
Quote from "the snake" himself from forums.radioreference.com:
 
"I am old school and I tune and align the radios buy ear and my pep meter and my bird wattmeter and my signal generator and DB meter for receiver peak settings . I have had people take radio`s that I have done to other shops with all the spectrum analyzers and scopes netc etc put my radio on there equiptment and it was right on the money."
 
Sure, I'll bet.  I ran a CB shop in Salina Kansas back in the 80s and early 90s, and I have seen and repaired thousands of these butcher-shop customs.  These days it is even worse with the influx of cheap Chinese and Italian MOSFET amp modules.
 
If you are really worried about your UHF being overloaded, use one of these filters between the output of your CB amp, and your CB antenna:
https://www.dxengineering.com/parts/mfj-704
That will filter out anything above 40 MHz to protect your other VHF and UHF radios, and prevent interfering with other services.  It's a pricey accessory, but it might be worth if for you, and it will certainly handle all of the power you will be able to throw at it.  Be sure to use a high-grade RG-214 coax jumper between the amp output and this filter.
 
OK, now that I have upset everyone, I'll sign off for the day.

It's a "Snake Radio Custom". In my opinion, a clueless "screwdriver expert".  Keep in mind Marc, the SSB power control in these radios is useless and no longer functional when the ALC transistor has been clipped out for "Maximum Swing" or whatever.  ..and Jesse, If it were a clean 100, or even 500 Watts at 27 MHz, it would in no way harm the Motorola UHF front-end, however this thing with its un-filtered chinese-made amp slab is very likely going to be grossly dirty on the spectrum, so no promises.  The only thing I can promise you is that no oscilloscopes, or spectrum analyzers, or professional technicians were used in the tuning of this "Super" radio.
 
Quote from "the snake" himself from forums.radioreference.com:
 
"I am old school and I tune and align the radios buy ear and my pep meter and my bird wattmeter and my signal generator and DB meter for receiver peak settings . I have had people take radio`s that I have done to other shops with all the spectrum analyzers and scopes netc etc put my radio on there equiptment and it was right on the money."
 
Sure, I'll bet.  I ran a CB shop in Salina Kansas back in the 80s and early 90s, and I have seen and repaired thousands of these butcher-shop customs.  These days it is even worse with the influx of cheap Chinese and Italian MOSFET amp modules.
 
If you are really worried about your UHF being overloaded, use one of these filters between the output of your CB amp, and your CB antenna:
https://www.dxengineering.com/parts/mfj-704
That will filter out anything above 40 MHz to protect your other VHF and UHF radios, and prevent interfering with other services.  It's a pricey accessory, but it might be worth if for you, and it will certainly handle all of the power you will be able to throw at it.  Be sure to use a high-grade RG-214 coax jumper between the amp output and this filter.
 
OK, now that I have upset everyone, I'll sign off for the day.

NOTE: RG-400u is NOT the same type of cable as LMR-400 or DX-400.  RG-400u is a smaller diameter, double-shielded cable, the size of RG-58u, for use as jumpers in a repeater system, or internal radio connections where signal leakage would be a problem.
 
LMR400 from TImes Microwave and its clone, the DX400 cable from DX Engineering is a larger cable, the size of RG-8u, that is supposedly rated for use up into the 400 MHz range with low-loss. It has its uses, and can be great for a GMRS base station, but not a repeater where it has to transmit and receive at the same time - that is where the trouble starts.
 
RG-400u, and its larger cousin RG-214u are Mil-Spec double-shielded, silver plated cables, specifically designed so that the signals between two closely-ran cables will not cross-talk into one another.  That's what you need is a repeater system.

Heat has not been an issue with my Kenwoods. They will not get hot enough to set anything on fire, or melt plastic. They will need a bit of airflow around the heatsink however, so don't bury them under anything, or mount them in an enclosed area without ventilation.

NOTE: RG-400u is NOT the same type of cable as LMR-400 or DX-400.  RG-400u is a smaller diameter, double-shielded cable, the size of RG-58u, for use as jumpers in a repeater system, or internal radio connections where signal leakage would be a problem.
 
LMR400 from TImes Microwave and its clone, the DX400 cable from DX Engineering is a larger cable, the size of RG-8u, that is supposedly rated for use up into the 400 MHz range with low-loss. It has its uses, and can be great for a GMRS base station, but not a repeater where it has to transmit and receive at the same time - that is where the trouble starts.
 
RG-400u, and its larger cousin RG-214u are Mil-Spec double-shielded, silver plated cables, specifically designed so that the signals between two closely-ran cables will not cross-talk into one another.  That's what you need is a repeater system.

One thing to keep in mind is what kind of range you will actually need.  For example, if you live in the center of a valley surrounded by tall mountains 5 miles away in every direction, there is no point in spending a lot of money for extra power or to reduce cable loss.  For example 20 watts into a 6db loss feed line might still cover the entire area quite well.
 
Also consider the criticality of the system. Is this just for fun and maybe a backup for a cell phone. Or, is this your sole means of communications. Once you answer that question, budget accordingly.
 
And, also step back a bit and look to see if there is another way to organize your installation. For example, instead of locating the radio 50 feet from the tower, can you create a small enclosure and house the radio at the base of the tower.  A good quality weatherproof garden shed, or even a large tool-box, might cost a lot less that 100 feet of high-end feedline.

Half the time I see people blaming a "bad duplexer" - it turns out to be the junk cables connecting the repeater to the duplexer. You should be using a good quality double shielded cable like RG400 with the correct ends (no adapters!).  Type N is the preferred connector, but if your repeater or duplexer has different connectors, you need to work with those.
 
Try someone like these guys  - avoid the cheap "tin" or nickel plated connectors - there's a few USA based sellers with similar products: https://www.ebay.com/itm/6-10-RG400-M17-N-Male-Clamp-Jumper-Silver-coated-RF-cable-USA/131269263466

I still think you are describing de-sense.  The one weak link you have in my opinion is that knock-off LMR-400 coax cable.  I also still wonder what you are using for jumpers between the radios and the duplexer.  Cheap CB coax jumpers will NOT work for that purpose.

If you want something lightweight that folds down for "just grab-and-go" temporary use, I have had good luck with PA system speaker stands such as:
 
https://www.parts-express.com/peavey-tripod-speaker-stand-ii-56-102-black-100-lb-capacity--248-8586
 
Add a 5-foot mast pipe to the top of this, and your antenna is instantly 12-15 feet in the air.  Add some rope and tent stakes for temporary guy wires if it's windy.