gortex2

Guys lets move this to another thread ? Think its a good discussion. 
 

The ICOM 4008 base was the design of the soldier inter-comm for the US Army. We sold many of those when I was at a ICOM shop. 

I did a similar design in NY. All 3 repeaters were the same output, however all three used a different input PL. I called it a poor mans voting system. There are similar systems in public safety. Actually our SAR system started the same. Same TX/RX all over the area with different input PL tones. All TX was the same PL.
 
Really need more info as said. 

As to legal power, I understand the rules to mean 50 watts (MAX) at the antenna port of the transmitter, as opposed to ERP (Effective Radiated Power/what the radiated signal is).

That said...

No matter what you do, there is going to be loss between the TX/RX and the antenna.  I don't know about 4dB 'in the box' but... 

The average (decent) duplexer has (or should have) 1.5dB or less insertion loss (each respective side, TX and RX), so there goes a 'watts' or so.  If you really like your TX, a circulator in the TX side is nice, but rarely done and, would likely add about, or just under, another dB of loss, so there goes another watt or so. 

It's fair to say that even if your TX is putting out 50W from the PA, by the time you connect to the antenna system, that 50W is going to be 30-40W (if you're lucky). 

That is, again, typical.  I'd add that the losses go both directions so your RX sensitivity just got a little worse as well (but not earth shattering).

This is why antenna system design is a make or break scenario.  The gain of the antenna ideally makes up for some of the line and perhaps even the duplexer loss and, if it has some gain, maybe focuses what energy it does radiate and receives where you want it.

As for tweaking the PA for more power, it doesn't really help, because once again, there is loss on the receiver side too, so upping the power is only going to make your repeater talk where it can't hear the people trying to talk into it.  As noted by another poster, it also risks cooking the PA itself and/or the power supply feeding it.

Now I know in the 'hobby' it isn't practical, but the ultimate goal of a repeater design/system is to be able to have the talk-in balanced with the talk-out for a given user radio and antenna combination.

You really can't do that thinking in watts, which is why the practice (for people who do all of the above) is to work in dB (decibels).  Why? Because losses and gains can be added up and subtracted to find out what you actually are dealing with.  Watts equates to a level of dB as does cable and other losses, antenna gain (or loss) and, the sensitivity of the receiver. 

Indeed, for all the hoopla about tweaking a PA and squeaking out a couple more watts, if you look at power output in dB as apposed to watts, you find even doubling the watts isn't really a whole lot of gain in the bigger picture.

FWIW...

From Post here - HERE
 
@Flameout said - "The cablelowering it and all of a sudden I could pick up the repeater. I just had lots of noise, especially compared to the mag mount Nagoya about 3' off the ground. I really wouldn't mind buying another antenna if I knew it would work. Too bad there isn't a store that rents them is 50' of ABR Industries RG 8/U and the SWR is great (but then again, it is also great using a dummy load) I had the antenna up about 20' but experimenting one day, I was"
@WROZ250 gave you some good info. For a base radio I'd use the best you can find. You said you are using 50'. Do you really need that much cable ? 
I would use the least amount as possible. I'll be honest I would not even entertain 50' of LMR myself but know not everyone can afford LDF cable. I would say if you can get down to 25' of cable you may find a much better experience. I will also suggest watching ebay for LDF. I have seen 50' chunks for around $100. You need to search and it may take some time but LDF is online and can be had reasonable. 
 

I wanted to throw out of post of good commercial antenna's that work great for GMRS as well as other LMR applications. Every antenna listed I have used for home and on towers and have had little if any issues with. 
Laird - Laird FG Series is a great antenna for home use and limited tower site use. Great for a home repeater when a tower is not available. Mostly omni. 
FG4500 - Unity Gain Fiberglass Antenna N Female 100W 450-470mhz - Cost around $125
FG4603 - 3db Gain Fiberglass Antenna N female 100W 460-470  - Cost around $140
FG4605 - 7db Gain Fiberglass Antenna N Female 100W 460-470 - Cost around $200
 
You can get more specifications from Laird here - FG Series Antennas
I get most of my hobby antennas from The Antenna Farm
The next step up is the dipole antenna and is normally the base antenna I'll install on a tower site. The DB aka CommScope Dipole is a rock solid performer and works well in long term use. I have used these in the ADK park on mountains caked in ice to towers in SE VA and other than physical damage never replaced one. 
DB404 - 3.8db Gain Dipole Antenna - N Male 250W 450-470mhz - Cost around $500
DB408 - 6.6db Gain Dipole Antenna - N Make 250W 450-470mhz - Cost around $1000
You can get more specifications from CommScope here - CommScope
I use various vendors for CommScope gear. Antenna Farm linked above does carry the DB404 as does MyGMRS. MyGMRS would be my first choice as it helps support the site and forum. His price is comparable to what I get it for from Tessco. 
When looking at an antenna also remember the cable to the antenna to be almost as important as the antenna. Putting a DB408 on a tower isn't going to perform as expected when you run LMR400 to it. It should be LDF. In reality if its on a tower it should be LDF anyway. 
Some real case uses of antenna''s above for me. My 38' Motorhome has a GMRS repeater. for years I ran the GR1225 and since have switch to the RT97. I run the FG4500 on my ladder and it works perfect for camgrounds/race track use. I have used the FG4605 for years on a repeater at my fathers house. He had a small mast system and it was a great match. I ran 1/2 LDF up the mast and to the antenna. The DB404 is my favorite. Thats what I have at home on a 1 1/4" Pipe on my roof. I run the DB408 at the tower with 7/8" LDF down to the combiner/duplexers. 
Just wanted to get some info out there on better antennas and options. TRAM, Comet, Ed Fong are all that. They are hobby antenna's and may not meet expectations. Some even cost the same. 
 
 

True, they would work far much less sucky on the moon or way out in the boondocks.

In fact, Midland backs up their 32 mile claim for their GMRS radios by testing them line of sight from a huge hill way out in some wide open rural area. The lawyers are happy, but folks who now have those radios, question the claim when they barely get a half mile in a suburban area.

I have some ICOM IC4008A FRS radios that are superhet, but very basic design with little preselector filtering, just a simple coil. Better than an SOC design. They work very well out in the National Parks. But around town, not so much. I keep them because they are easy to use and the AA batteries last days when camping. My wife and son carry them because they are small.

A radio is a tool like anything else. A battery operated drill from China sold at Harbor Freight might get by for the casual home user. But I have a Japanese Makita drill I purchased in 1980 for $300 in 1980 dollars , that has outlasted all of the cheap drills I bought in the meantime. For $35 You are not getting much of a drill. Same for cheap radios.



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Tram Browning BR-6140, $51 on amazon and elsewhere. Unity gain, 2 ft tall, N connector, comes with mounting hardware.

I think so, the Harvest brand folded dipole goes for 70 bucks on eBay. The 2 bay dipole goes for 140 bucks on eBay. I think folded dipoles are great b/c they have super wide bandwidth and they are very resilient to noise.
single dipole link: https://www.ebay.com/itm/133810193897?epid=1941709490&hash=item1f27b585e9:g:Y5EAAOSwLCdgUyaI
2-bay link: https://www.ebay.com/itm/133927735178?epid=1941709490&hash=item1f2eb70f8a:g:yowAAOSwIytgUyhQ

Guys lets get back to the Midland MTX500 stuff.
There is a section in the forums for arguing called Amateur Radio or Miscellaneous Topics

If you want a cheaper folded dipole, which I recommend over anything vertical, here are a more budget friendly option for UHF.
-Harvest FDU1 310~480 MHz UHF 500W Folded Dipole. 70 bucks. - Costs around $70
-Harvest FDU2 310~480 MHz UHF 500W 2-Elements Folded Dipole Array Antenna. - Costs around $140
 
For VHF, I've had excellent results with the following dipole (not folded), and its not too expensive. You can build a 2-bay, 4-bay, 8-bay etc, array out of those.
-Sirio WD140-N VHF 140-160 MHz Base Station Dipole Antenna - Costs around $99 
specs can be found at the Sirio site: https://www.sirioantenne.it/en/products/vhf/wd-140-n-wd-155-n
This antenna is very high quality, in fact, I think it might be better built than the newer Commscope DB antennas (not the old ones)

I wanted to throw out of post of good commercial antenna's that work great for GMRS as well as other LMR applications. Every antenna listed I have used for home and on towers and have had little if any issues with. 
Laird - Laird FG Series is a great antenna for home use and limited tower site use. Great for a home repeater when a tower is not available. Mostly omni. 
FG4500 - Unity Gain Fiberglass Antenna N Female 100W 450-470mhz - Cost around $125
FG4603 - 3db Gain Fiberglass Antenna N female 100W 460-470  - Cost around $140
FG4605 - 7db Gain Fiberglass Antenna N Female 100W 460-470 - Cost around $200
 
You can get more specifications from Laird here - FG Series Antennas
I get most of my hobby antennas from The Antenna Farm
The next step up is the dipole antenna and is normally the base antenna I'll install on a tower site. The DB aka CommScope Dipole is a rock solid performer and works well in long term use. I have used these in the ADK park on mountains caked in ice to towers in SE VA and other than physical damage never replaced one. 
DB404 - 3.8db Gain Dipole Antenna - N Male 250W 450-470mhz - Cost around $500
DB408 - 6.6db Gain Dipole Antenna - N Make 250W 450-470mhz - Cost around $1000
You can get more specifications from CommScope here - CommScope
I use various vendors for CommScope gear. Antenna Farm linked above does carry the DB404 as does MyGMRS. MyGMRS would be my first choice as it helps support the site and forum. His price is comparable to what I get it for from Tessco. 
When looking at an antenna also remember the cable to the antenna to be almost as important as the antenna. Putting a DB408 on a tower isn't going to perform as expected when you run LMR400 to it. It should be LDF. In reality if its on a tower it should be LDF anyway. 
Some real case uses of antenna''s above for me. My 38' Motorhome has a GMRS repeater. for years I ran the GR1225 and since have switch to the RT97. I run the FG4500 on my ladder and it works perfect for camgrounds/race track use. I have used the FG4605 for years on a repeater at my fathers house. He had a small mast system and it was a great match. I ran 1/2 LDF up the mast and to the antenna. The DB404 is my favorite. Thats what I have at home on a 1 1/4" Pipe on my roof. I run the DB408 at the tower with 7/8" LDF down to the combiner/duplexers. 
Just wanted to get some info out there on better antennas and options. TRAM, Comet, Ed Fong are all that. They are hobby antenna's and may not meet expectations. Some even cost the same. 
 
 

I ran this antenna for many years in a few specific vehicles. Its rated for 35 watts and works well as long as its in site. Don't stuff behind trim. Just 3M tape to the rear glass. 
https://www.amazon.com/Covert-SB450FME12-450-470mhz-Internal-Antenna/dp/B007JSDDFA
Mine was from Laird I think but doesn't come up on there site ant longer. Heck I may still have one in the parts box out in the barn. They made one for 800 that we used alot for volunteer fire chiefs when we were 800mhz. 
I would think this would work well for your application. 

Nice ride!!
Fiberglass is even worse than aluminum, at least aluminum is metal...  
G.
EDIT: Hope you are using Motorola APX radios in that ride... no excuse to buy a CCR... LOL

So, no mag mount, no lip mount, and you don't want to drill holes.  Have to be honest, i have no idea what else you could possibly do except use your handheld.  I mean, you are asking how to mount an antenna without mounting an antenna... so holding it is all that is left.
 
What kind of vehicle is it?  I mean, I put a lip mount on a $100k Challenger Hellcat that was even painted black and had zero issue with the paint.  That really is the best method if you want it to work and not have damage.

You will spend more money on cable and connectors than the antenna many times. Spend more on the proper antenna. As gman1971 said terminate the cable where it breaches the building and ground with proper lightening protection (again $$) then run a smaller cable. If a short cable (under 10')  is needed RG142 or similar could be used to the mobile/base/portable. 
With all of this said manage expectations. Using ham grade home made antenna and RG8 cable will not give you the benefits you hope for in most cases. There will be those that claim its better but YMMV. Determine your use case. If this is a repeater or abase for simplex spend the funds and do it right. If its just a way to hit a local repeater then you may not need what you are looking for. 

don't forget your jumper from TX to the duplexer has loss. If you use a cheap jumper I have seen some with almost another DB of loss. Did the duplexer get tuned for the channel you are using ? 
 

Michael, 
Please provide us with your definition of influencer. I saw the post as an announcement with nothing to indicate a person should purchase this item due to his standing in the forums.

don't forget your jumper from TX to the duplexer has loss. If you use a cheap jumper I have seen some with almost another DB of loss. Did the duplexer get tuned for the channel you are using ? 
 

Appears same as the TRAM 1481 and most likely made by the same china company. Most of the multi piece trams fall apart after a few years. Basically a hoppy antenna. Mine last 2 months in NY before it snapped in the wind. Since them I only use commercial LMR antennas made by reputable companies.
 

Few years is more like few months. They develop water ingestion and the foam inside soaks water so things corrode real fast. 
Verticals tend to shoot out with a vertical takeoff angle, so it will reach very far, but up on the clouds... instead of a gigantic (and usually ineffective) antenna, I would get this for UHF:
https://www.ebay.com/itm/133927735178?epid=1941709490&hash=item1f2eb70f8a:g:yowAAOSwIytgUyhQ
G.

Appears same as the TRAM 1481 and most likely made by the same china company. Most of the multi piece trams fall apart after a few years. Basically a hoppy antenna. Mine last 2 months in NY before it snapped in the wind. Since them I only use commercial LMR antennas made by reputable companies.
 

@MichaelLAX Did repeating the same thing over and over made you feel any smarter today? or did it give you a headache instead? or is it just listening to yourself all the time what gives you headache? oh, must be the details.

This is another reason why I try to tell everyone in this forum to not buy CCRs...  
G.

I recall when the first lawsuit came out, and former co-workers of mine had just bought Hytera radios to save some money, based on the fact that they worked perfectly with the then newly produced Motorola XPR6550 radios. However, I asked if they had tested them with something "smarter" than an old HP8920 RF Communications Test Set. They brought one to my office and we tested side by side Motorola versus Hytera, and there was a reason they were cheaper.....they looked similar, functioned similar, but to worse specifications. But, they were cheaper they said. 
Intellectual property theft should have consequences, but China only bears part of the fault. Schaumburg is a shadow of what it once was, producing very few Motorola radios in 2022. Outsourcing to Malaysia and Mexico has hurt Motorola in ways they have yet to understand. Thank you for sharing the news OP, this is something I have been tracking since it began a decade ago, and it is still interesting.