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Muzic2Me
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Installed my new 50 mobile as a base station on a 5 db Ed Fong antenna 25' up tuned for GMRS. Purchased a 20" UT-72G 3.5 db magnetic for the vehicle attached to the HT. I honestly did not tell the difference at all in distance between the roof mount antenna and my Whip for the HT.  I am in a rural area with plenty of trees. I think the best I got was a mile.  I am wondering if the HT at the house on the higher Antenna and the mobile in the vehicle would increase the range?  Slowly acquiring more equipment as fast as the $ will grow on the tree out back. 

I know its line of sight and the higher I can get is better. THis is what I am experimenting with as how high I need to go for promising communication. Then I can purchase/build the height I need. OR I need another mobile for the vehicle.

    

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Installed my new 50 mobile as a base station on a 5 db Ed Fong antenna 25' up tuned for GMRS. Purchased a 20" UT-72G 3.5 db magnetic for the vehicle attached to the HT. I honestly did not tell the difference at all in distance between the roof mount antenna and my Whip for the HT.  I am in a rural area with plenty of trees. I think the best I got was a mile.  I am wondering if the HT at the house on the higher Antenna and the mobile in the vehicle would increase the range?  Slowly acquiring more equipment as fast as the $ will grow on the tree out back. 
I know its line of sight and the higher I can get is better. THis is what I am experimenting with as how high I need to go for promising communication. Then I can purchase/build the height I need. OR I need another mobile for the vehicle.
    

Your experience sounds soooooo familiar. :)

Your experience is pretty consistent with mine under similar conditions and setup. I too have loads of trees.

Spoiler alert. I expect zero difference in your tests if you swap the radios and keep everything else the same, nor do I expect there to be any more than a small insignificant increase in range if you put high-power mobiles in both location. Since you are experimenting, please do so. We always learn best by doing.

Now that you are one your journey to a true understanding of the real meaning behind ‘line of site’ communications, consider this. In my experience, because of all the trees and other obstacles in your path, small increases in antenna height will be met with minor, if not completely undetectable, differences. Double your height and I expect you’ll clearly detect a change, albeit modest. Get one of your antennas above the trees and suddenly things really open up. Get both above the trees and WOW!.


Michael
WRHS965
KE8PLM
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2 hours ago, mbrun said:


Your experience sounds soooooo familiar. :)

Your experience is pretty consistent with mine under similar conditions and setup. I too have loads of trees.

Spoiler alert. I expect zero difference in your tests if you swap the radios and keep everything else the same, nor do I expect there to be any more than a small insignificant increase in range if you put high-power mobiles in both location. Since you are experimenting, please do so. We always learn best by doing.

Now that you are one your journey to a true understanding of the real meaning behind ‘line of site’ communications, consider this. In my experience, because of all the trees and other obstacles in your path, small increases in antenna height will be met with minor, if not completely undetectable, differences. Double your height and I expect you’ll clearly detect a change, albeit modest. Get one of your antennas above the trees and suddenly things really open up. Get both above the trees and WOW!.


Michael
WRHS965
KE8PLM

I appreciate the knowledge and sharing of your experiences with the set up. I'm down the Rabbit trail now. I have searched endlessly for a mast or tower that is tall enough that I can do away with guys and tilt/pivot. Tough to find one that supports higher than 40' on a tilt base without guying. Might be my only option to guying. Shipping is getting costly, so I may have to drive and pick one up also. The joys!!! Thanks for sharing WRHS965

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Hi, 

 I would determine what the noise floor in your area is, I've seen rural areas with a surprisingly high noise floor... Then, after you determine that, I would then measure the effective sensitivity of these radios, by performing an ISOtee with the antenna(s) you plan on using. Once you determine the noise floor and the effective sensitivity, you'll be ready to start making educated decisions, rather than just going down the rabbit trail without knowing why something is happening.

G.

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5 hours ago, gortex2 said:

a better base antenna would help for simplex. Also you never mentioned what cable you use on the base radio. 

I purchased 50' of RG-8/U. which showed a 50', not the worst db loss/ I was ready to just get an antenna up, so I am in a temporary holding pattern with that until I figure my final plan. Fong antenna UHF is 3.5db.

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5 hours ago, gman1971 said:

Hi, 

 I would determine what the noise floor in your area is, I've seen rural areas with a surprisingly high noise floor... Then, after you determine that, I would then measure the effective sensitivity of these radios, by performing an ISOtee with the antenna(s) you plan on using. Once you determine the noise floor and the effective sensitivity, you'll be ready to start making educated decisions, rather than just going down the rabbit trail without knowing why something is happening.

G.

Gman1971,

Thanks for the informative info. I can see that I will need equipment to do these. Here are the specs on the sensitivity of the mobile at diff bands. Most are Rx of course. Im GMRS.

400.000-479.995MHz:0.25uV(13dB SINAD) 136.000-174.995MHz:0.25uV(13dB SINAD) 50.000-53.995MHz:0.25uV(13dB SINAD) 320.000-349.995MHz:0.25uV(13dB SINAD) 700.000-985.995MHz:-97.0dBm(13dB SINAD).

 

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39 minutes ago, Muzic2Me said:

Gman1971,

Thanks for the informative info. I can see that I will need equipment to do these. Here are the specs on the sensitivity of the mobile at diff bands. Most are Rx of course. Im GMRS.

400.000-479.995MHz:0.25uV(13dB SINAD) 136.000-174.995MHz:0.25uV(13dB SINAD) 50.000-53.995MHz:0.25uV(13dB SINAD) 320.000-349.995MHz:0.25uV(13dB SINAD) 700.000-985.995MHz:-97.0dBm(13dB SINAD).

 

Hi there,

as gortex2 stated, cable is rather important, especially at UHF or above freqs.

Personally, I would dump the RG-8/U and go with LDF-50 1/2 inch heliax with trimetal N-connectors. BUT.... big if.... if all you are going to do is simplex then I would entertain genuine LMR600. With either silver or trimetal N-connectors, especially for indoor runs. I wouldn't waste any money on PL259/SO239 for anything above 300 MHz, it can't hold impedance well at higher freqs, so you might end up going down a very deep rabbit hole ... not fun.

Personally, I run multiple 40 foot sections of LMR600 with silver plated N-connectors for my UHF GMRS base setup (no repeater) at home. Loss is very small. For anything else I have, everything is heliax LDF-50 1/2"

The Effective Sensitivity (or dynamic sensitivity) is not the advertised sensitivity figure on the radio. In order to determine the dynamic sensitivity figure you need to perform an isotee test on the radio. Nowadays, it seems that noise floor is pretty much the limiting factor as to how far you'll be able to hear the base.

As for Antenna, after trying over two dozens of ham grade stuff, I wouldn't waste my money on anything vertical, go straight to either a half wave dipole or a half wave folded dipole. You will not be disappointed.

G.

 

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7 minutes ago, gman1971 said:

Hi there,

as gortex2 stated, cable is rather important, especially at UHF or above freqs.

Personally, I would dump the RG-8/U and go with LDF-50 1/2 inch heliax with trimetal N-connectors. BUT.... big if.... if all you are going to do is simplex then I would entertain genuine LMR600. With either silver or trimetal N-connectors, especially for indoor runs. I wouldn't waste any money on PL259/SO239 for anything above 300 MHz, it can't hold impedance well at higher freqs, so you might end up going down a very deep rabbit hole ... not fun.

Personally, I run multiple 40 foot sections of LMR600 with silver plated N-connectors for my UHF GMRS base setup (no repeater) at home. Loss is very small. For anything else I have, everything is heliax LDF-50 1/2"

The Effective Sensitivity (or dynamic sensitivity) is not the advertised sensitivity figure on the radio. In order to determine the dynamic sensitivity figure you need to perform an isotee test on the radio. Nowadays, it seems that noise floor is pretty much the limiting factor as to how far you'll be able to hear the base.

As for Antenna, after trying over two dozens of ham grade stuff, I wouldn't waste my money on anything vertical, go straight to either a half wave dipole or a half wave folded dipole. You will not be disappointed.

G.

 

Thanks for all the valuable experience and knowledge. Question?.. On this larger Coax, one must convert at some point to more flexible to get it to the radio, correct?, or No?

 

Thanks again for the input.

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4 minutes ago, Muzic2Me said:

Thanks for all the valuable experience and knowledge. Question?.. On this larger Coax, one must convert at some point to more flexible to get it to the radio, correct?, or No?

 

Thanks again for the input.

Glad I could help,

Yes, you probably don't want to run the anaconda heliax to the radio. Sorry for leaving this important bit out... what I do is run the Heliax up to the main ground plate, where all the N bulkhead connectors are (this plate is usually grounded), and on the other side of the bulkhead N connector I run short 4-feet patch cables of RG-400 with silver N-connectors to the filters, and then another 3-4 feet RG-400 from the filters to the radio/repeater.

G.

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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. 

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