Distance issue Motorola Maxtrac & X-300

[linboogy]

Hello all, and thanks in advance for any help you may shed light on
I have just recently purchased a Motorola Maxtrac 25 watt UHF and X-300 base antenna. The radio is programed for our local skywarn and our family GMRS freq. The system was set up so I can talk to relatives that are in my area ranging from 3 miles to 10 miles via Motorola Ht1000's in the event of a disaster or emergency. I have installed the X-300 base antenna on a 10 foot piece of mast in the back yard and used RG8 50 ohm coax to the radio.
The problem is that I cant even hardly reach the relative that lives only 3 miles away. They can hear me with a great deal of static but I cant hear them at all even with the squelch broken. I have also tested this with my wife by driving around the area and it seems to only reach reliably about 1 mile give or take with a handheld in the car. I have multi meter tested my connections and all are ok. I even temporarily setup a Diamond mobile dual band antenna with even worse results. I cant believe this is all of the range I can get out of this setup.
Should I extend the antenna up higher?
Thanks again for looking and I apologize if I posted this in the wrong forum
Thanks
Eric

 

[mmckenna]

Couple of issues:

The X-300 is a dual band amateur radio antenna. It's designed to work optimally from 144-148MHz and 430-450 MHz. The GMRS frequencies are in the 462 range. While the antenna should work OK, it's not going to be an ideal performer.

Antenna height is key. If your antenna is only 10 feet up, that is likely a major issue. UHF is -mostly- line of site, so getting your antenna up higher is important.

Coaxial cable can be a key factor too. RG-8 isn't the best stuff, but if your run is short, it should be OK. You didn't say how long the run was.

The hand held radios on the other hand can be an issue also. They are limited by their relatively inefficient antenna, and this works for transmitting and receiving. The fact they can hear you slightly, but you can't hear them reinforces this. Your transmitted signal is stronger than theirs, hence the one way nature.

Elevating your antenna should help quite a bit. Get it well above your roof line. The higher the better. If your coax run is really long, you either need to shorten it, or get a higher grade coax.

Good luck!

 

[N8IAA]

Hello all, and thanks in advance for any help you may shed light on
I have just recently purchased a Motorola Maxtrac 25 watt UHF and X-300 base antenna. The radio is programed for our local skywarn and our family GMRS freq. The system was set up so I can talk to relatives that are in my area ranging from 3 miles to 10 miles via Motorola Ht1000's in the event of a disaster or emergency. I have installed the X-300 base antenna on a 10 foot piece of mast in the back yard and used RG8 50 ohm coax to the radio.
The problem is that I cant even hardly reach the relative that lives only 3 miles away. They can hear me with a great deal of static but I cant hear them at all even with the squelch broken. I have also tested this with my wife by driving around the area and it seems to only reach reliably about 1 mile give or take with a handheld in the car. I have multi meter tested my connections and all are ok. I even temporarily setup a Diamond mobile dual band antenna with even worse results. I cant believe this is all of the range I can get out of this setup.
Should I extend the antenna up higher?
Thanks again for looking and I apologize if I posted this in the wrong forum
Thanks
Eric

You have a few problems to overcome.
First, You are using an antenna meant for 2m/70cm use, not GMRS.
Second, GMRS licensing only covers those who are immediate family living in the same residence. So, unless the family members live with you, they'll need their own license.
Third, you are probably using simplex frequencies. 5 watts on UHF travels reliably only one mile. Regardless of what is stated on the bubble pack radios.
Having access to a repeater would solve the distance problem. You'll need to get permission from a repeater owner in your area.
HTH,
Larry

 

[mmckenna]

Second, GMRS licensing only covers those who are immediate family living in the same residence. So, unless the family members live with you, they'll need their own license.

Not quite. There is no requirement that they be under the same roof.

Third, you are probably using simplex frequencies. 5 watts on UHF travels reliably only one mile. Regardless of what is stated on the bubble pack radios. ]

He stated in his post that he's using HT1000's. While not ideal, an HT1000 will outperform a bubble pack radio any day.

 

[LtDoc]

You've gotten the best advice already, raise your antenna as high as possible and to use a coax cable that's more appropriate at UHF. Since you will only be using UHF, an antenna not made specifically for more than one band -might- be of benefit. I'd try what I had first, then decide.
The most limiting factor when using any HT is it's antenna, most furnished antennas (rubberduck) are for very short distances and convenience, not performance. The same 'cure' applies to them, mostly antenna height. Antenna height isn't a 'cure-all' but it's probably the 'cheapest/dirtiest' fix in most cases. Terrain is a biggy too. What between stations 'obstructs' the signal, there's almost always something.
Have fun.
- 'Doc

 

[linboogy]

Thanks you all very much for the advice.
The X-300 is UHF only part 7210-9-460-470 covering 460-470
We have no bubble wrap radios here. All are retired Motorola HT1000 from our police department when they upgraded to digital 800 trunking. As far as a repeater, I would not want to depend on one in an emergency or disaster. My coax is long. It was a 100 foot roll so I coiled it up where it penetrates the house. I didn't realize this would have an effect and I didn't realize RG8 was not ideal. I am going to extend the antenna another 5 feet at least today and test the range on it and wack the extra coax off.
Thanks again
Eric

 

[kayn1n32008]

Thanks you all very much for the advice.

The X-300 is UHF only part 7210-9-460-470 covering 460-470

We have no bubble wrap radios here. All are retired Motorola HT1000 from our police department when they upgraded to digital 800 trunking. As far as a repeater, I would not want to depend on one in an emergency or disaster. My coax is long. It was a 100 foot roll so I coiled it up where it penetrates the house. I didn't realize this would have an effect and I didn't realize RG8 was not ideal. I am going to extend the antenna another 5 feet at least today and test the range on it and wack the extra coax off.

Thanks again

Eric

Yea, get rid of that RG-8. It is garbage on UHF. That will be a big part of your range problems. 100' is going to attenuate the signal a lot. You are going to lose about 3/4 of the power you put into it. 50 in one end will only be 17w at the antenna.


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[AK9R]

Are you using amateur radio or GMRS frequences?

 

[linboogy]

Yea, get rid of that RG-8. It is garbage on UHF. That will be a big part of your range problems. 100' is going to attenuate the signal a lot. You are going to lose about 3/4 of the power you put into it. 50 in one end will only be 17w at the antenna.


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What coax do you suggest?

 

[kayn1n32008]

What coax do you suggest?

Bedlam 9913, or even 1/2" hard line. If your run can be short 9913 will be ok. Do not buy knock off, if your run is going to be more than 25-50' go with 1/2" hard line.


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[linboogy]

Still no luck
I have attached a picture of the new location of the antenna. It is in the same area as the radio that is located in the basement and it is now above the roof line of a 2 story house. The base of the antenna is 23 feet from the ground. I could of went higher but I don't want it to be seen from the street if at all possible. I have also reduced my coax from 100 feet to 37 feet. I am still getting the same results of not being able to talk 3 miles outside of extreme static and I cant hear anything from the remote HT. I don't have access to the suggested coax this weekend but we have a local Ham shop that has just about everything open during the week.
Is it safe to assume its the coax at such a short distance? The Motorola Maxtrac was off of Ebay and I have no idea what this history is on it. I am going to try my trusty old Yaesu 51r if I can find an adapter tonight and see if I can eliminate the radio out of the culprit.
Thanks
Eric

 

[linboogy]

Just thought I would update again
Strange thing. Accidently found out that the family member 3 miles away can hear me almost crystal clear ht1000 to ht1000. My HT even has a small stubby antenna! I am for sure I have something wrong with the base setup now. I was able to test my Yaesu 51R with the same results as the Maxtrac on the base antenna. I think I am going to abandoned all the coax and connectors and start over.

 

[KD8BIW]

Have you tested the SWR of the antenna or checked for a short or open on the coax?

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[mm]

in addition to testing the antenna, have you tested the E-Bay maxtrac to see if it has any output power?

Now I'm not saying that the possibility of purchasing something on E-Bay that doesn't function has occurred, after all we know that everything on E-Bay is top notch, but still I'd check the maxtrac output power.

You mentioned worse performance with a 2nd uhf antenna, even with a temporary mobile whip and a 25watt maxtrac, you should easily see 10 miles DFQ.

But I agree it is a antenna system failure but also check the transmitter.

With my luck I also have a radio failure along with an antenna failing, don't be surprised if after changing to a good new antenna system that u still have range issues.

I had a similar problem with a 220 rptr, a failing antenna took out the transmitter power amp resulting in a replacement of every component from the transmitter to the antenna, minus the hardline that was the only thing that didn't fail.

 

[linboogy]

I don't have an SWR meter or any way of determining the power output but I did use a multi meter to insure that no short was present and I have continuity on both ends of the coax. One thing I am concerned about is the radio shack adapters I am using. I am going through 2 sets of adapters. Maybe I should start with getting an SWR meter. Do you all think I can use a cheapy from Radio Shack?

 

[KevinC]

Thanks you all very much for the advice.
The X-300 is UHF only part 7210-9-460-470 covering 460-470
We have no bubble wrap radios here. All are retired Motorola HT1000 from our police department when they upgraded to digital 800 trunking. As far as a repeater, I would not want to depend on one in an emergency or disaster. My coax is long. It was a 100 foot roll so I coiled it up where it penetrates the house. I didn't realize this would have an effect and I didn't realize RG8 was not ideal. I am going to extend the antenna another 5 feet at least today and test the range on it and wack the extra coax off.
Thanks again
Eric

I can't find a x-300 that covers 460-470. I did find a cheap knockoff with the part number you listed that covers that range. Are you transmitting on GMRS or the amateur band?

 

[KD8BIW]

Do you have another antenna, even a mobile one, that you can use for testing? How about some different coax to swap? I'm not sure that radio shack sells an SWR meter that covers UHF, think they only cover CB. Ask some of your local amateur radio operators for some help, in sure at least 1 of them would have a SWR and/or power meter for testing.

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[linboogy]

Do you have another antenna, even a mobile one, that you can use for testing? How about some different coax to swap? I'm not sure that radio shack sells an SWR meter that covers UHF, think they only cover CB. Ask some of your local amateur radio operators for some help, in sure at least 1 of them would have a SWR and/or power meter for testing.

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Before I seen your response, I ran up to radio shack and grabbed their only SWR meter that indicated it cover low to high CB and HAM frequency's. After opening it, the directions says it covers only up to 30 MHz LOL
I went ahead and tried it anyway, and assuming it is even remotely accurate with UHF, its appears to be reading about 25 watts but it’s really difficult to tell with the way the meter scale reads but it maxes out the 20 watt scale. The SWR is claiming 1.2ish but I am sure this is inaccurate. I have already tried my 15 year old Diamond ham dual band mobile antenna using the same coax with the same results before I relocated the antenna higher. I only have a small 1.5 foot jumper so there is no feasible way for me to test out another coax at least right now. My Yaesu 51R only has the 4.8 pack and it may only be pumping 2 watts if I remember correctly so testing it for comparison may have been a bad idea.

I can't find a x-300 that covers 460-470. I did find a cheap knockoff with the part number you listed that covers that range. Are you transmitting on GMRS or the amateur band?

GMRS

Again, Thank you all very much for your help thus far. I am going to go to R&L electronics at some point soon and buy the best coax I can afford and replace all the connectors and junk the radio shack stuff. I am hoping I can get rid of the adapters as well but I am pretty sure I will need to keep the mini UHF adapter.

 

[linboogy]

Just thought I would update
I went to a local HAM shop this morning and brought the radio and a piece of the coax I used with me. I did not realize this but I have LMR-400 coax, not RG8. The tech said as long as I was under 75 feet it should work ok, so I did not replace that. He also tested the radio for power and to make sure it was on frequency and it was ok as well. After explaining the situation, and testing the radio, it was clear that its the antenna or the adapters. He got me all Amphenol connectors and I brought the Opek UH2401 antenna he suggested along with a Jetstream SWR meter that covers UHF. I have replaced the antenna already and checked the SWR. It is at (4.5ish) so I didn't bother trying to do a distance check. He did warn me I would have to trim it and not to transmit if it was over 1.5. This will be my first time matching an antenna. I am going to take it back down tomorrow and follow the suggested trimming chart I found after I had it installed of course. It looks as if I need to chop a total of almost 9 inches off of the different segments if I am understanding this correctly.
Thanks
Eric

 

[KD8BIW]

Before taking it down, see if there is a noticeable difference in the receive. If not, I'm still wondering about a coax issue. What type if connectors are on the ends? PL259, N, BNC? Are they crimp on or soldered?

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