Just got an XTL1500 as part of a grant. Wondered if I could plug in an VoCom VVC100-25 amplifier on it. Without the amp we can transmit to our town lines, but it does not help with mutual aid situations. I already had the VoCom from a previous install. I contacted Motorola Support with no clear answer. I was told the radio is set up currently at 50watts. Would like to get to 100watts.
Let me throw out a disclaimer that I am not technically savy and will not understand technical jargon. Looking for a basic yes or no. If no, just give me a simple reason like - "It will blow up". Thanks in advance for your help.
External Amplifier on a Motorola XTL1500
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folsomcvpd
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Re: External Amplifier on a Motorola XTL1500
You need to know the answers to the following questions before doing this:
1. Is the amplifier the same band as the mobile radio? (are they both VHF, etc.)
2. Is the amplifier tuned for the frequency on which the mobile radio will be transmitting?
3. What is the input power of the amplifier? You don't want to exceed rated input power of the amplifier or you'll have a mess on your hands one way or the other.
4. Can your antenna network handle the output power of the amplifier?
5. Will your power supply support the electrical current needs of the mobile radio plus the amplifier?
6. Are you licensed to run the rated output power of the amplifier + gain of the antenna? In other words, does the license allow the transmitter output power plus ERP that you'd be generating?
As you can see, the answer is not as simple as "yes or no" if you want to do things properly.
1. Is the amplifier the same band as the mobile radio? (are they both VHF, etc.)
2. Is the amplifier tuned for the frequency on which the mobile radio will be transmitting?
3. What is the input power of the amplifier? You don't want to exceed rated input power of the amplifier or you'll have a mess on your hands one way or the other.
4. Can your antenna network handle the output power of the amplifier?
5. Will your power supply support the electrical current needs of the mobile radio plus the amplifier?
6. Are you licensed to run the rated output power of the amplifier + gain of the antenna? In other words, does the license allow the transmitter output power plus ERP that you'd be generating?
As you can see, the answer is not as simple as "yes or no" if you want to do things properly.
Re: External Amplifier on a Motorola XTL1500
A VVC100-25 is a VHF 100w amp with a max 25w drive. So, the XTL is turned up a bit too high. The Vocon will blow up.
On the other hand, you're only down 3db. A gain antenna will make up for that.
On the other hand, you're only down 3db. A gain antenna will make up for that.
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folsomcvpd
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Re: External Amplifier on a Motorola XTL1500
Thanks for the answers. It is my understanding that xtl can have it's power adjusted. If I turn it down to 25watts it would then be in the range for the VoCom, then could I run it?
This system was in place with a previous radio and it is licenced, tested and power proven through the old radio.
This system was in place with a previous radio and it is licenced, tested and power proven through the old radio.
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Tom in D.C.
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Re: External Amplifier on a Motorola XTL1500
But you might wish to re-read what Bill G. told you. If you're running a quarter wave antenna now the substitution of a 3db gain antenna will do approximately the same thing for your system as installing a 100-watt amplifier. Simpler, cheaper, fewer possible problems, with the same results as putting in an amplifier.
Tom in D.C.
In 1920, the U.S. Post Office Department ruled
that children may not be sent by parcel post.
In 1920, the U.S. Post Office Department ruled
that children may not be sent by parcel post.
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CTAMontrose
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Re: External Amplifier on a Motorola XTL1500
Not to mention the better antenna would give you +3db gain on RX as well, not just 3db on TX with the amp alone.
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folsomcvpd
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Re: External Amplifier on a Motorola XTL1500
Thanks guys, I will check into the gain antenna.
I appreciate the help.
I appreciate the help.
Re: External Amplifier on a Motorola XTL1500
With the advent of wide radios, in most applications I find a gain antenna more of a hindrance than a help.
The bandwidth is going to limit you to a few megs around the center frequency. Which means no FED operations with that radio unless you are willing to accept a poor SWR.
How many people in this forum can tell the 3db difference between a 50w radio and a 110w radio in the field, please raise your hands.
In many applications you will find (expecially in the fire service) precise limitations on the output power you can use on mutual aid channels, particular in the NIFC frequencies. Sometimes a 110watt radio precludes you from operating. I have sent several strike teams from private contractors back with the recommendation that they only bring handhelds next time and leave their 110w radios at home....
The bandwidth is going to limit you to a few megs around the center frequency. Which means no FED operations with that radio unless you are willing to accept a poor SWR.
How many people in this forum can tell the 3db difference between a 50w radio and a 110w radio in the field, please raise your hands.
In many applications you will find (expecially in the fire service) precise limitations on the output power you can use on mutual aid channels, particular in the NIFC frequencies. Sometimes a 110watt radio precludes you from operating. I have sent several strike teams from private contractors back with the recommendation that they only bring handhelds next time and leave their 110w radios at home....