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FM transmitter system for ~60 miles range.

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sram

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I apparently posted this in the wrong section. Although the guys there helped alot and I thank them for that but I'll still post it here again since it is a more appropriate section.

We have this mini radio station running for purposes I don't really need to mention here. We are using a FM transmiter which has according to its specs a maximum output power of ~340 watts. They have it set at about 282, and according to the users it covers 8 km radius. Now, I'm not into this, but I have been given the task of increasing this range. I don't remember the antenna gain out of the top of my head. They want to increase it to 100 km!

So, what are my options? Get a more powerful transmiter with the approriate gain antenna and fix it in a high enough place and call it a day?

The system they are using is MIZAR FM system.


In the other thread you can see that I posted an offer from one company I contacted and I'd like to know if it is good for what I want to achieve.

This is the other post: https://www.electro-tech-online.com/threads/mini-fm-radio-station-need-more-range.114275/


And this is the quotation + Antenna:


1 TFM-1000, 1KW solid state FM Transmitter
1 fm broadcast antenna

some of the features;
redundant modular design
transmitter certified by the FCC.
on board monitoring of all transmitter parameters
VSWR foldback/temperature protection
brute force, heavy duty power supply
frequency agile
stereo encoder
HD ready
two year warranty, covers defects in material and workmanship.
tech support and factory training
estimated delivery time is 6 weeks

we have a best price guarantee

total price $9,600.00 usd


Please advise.

Thanks.
 
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I'd like to see a copy of your FCC license to operate a radio station at that power... The transmitter+antenna being FCC certified does not give you a legal right to broadcast.
 
I'd like to see a copy of your FCC license to operate a radio station at that power... The transmitter+antenna being FCC certified does not give you a legal right to broadcast.

Why is everybody asking about the license? What? You want me to upload a copy of it here? I'm only asking technical questions here and not discussing FCC regulations. The request has been submitted and whether they grant us a license or not, that's not my problem. I don't even care. I'm only in charge of the technical part of the matter. If no license is given, fine we are not buying what is in the quote. It is as simple as that. As a matter of fact, the license will just be given. I'm talking big entities here. It is government to government.

That aside, please contribute to this thread. I'm a long time reader here and I know there are well-educated people with lots of experience. I have limited knowledge myself regarding this, hence this thread.

Thanks
 
The reason we're all asking is because, as I've said previously, you're going about it the wrong way.

You get your licence (or at least find out what it allows), THEN get equipment to match those conditions.

What's the point of spending time and effort sourcing gear that will be of no use?.
 
If your experience is this limited why are you even part of the process? You already have a moderately high powered transmitter, what you're looking for is a commercial RF amplifier. You should be contacting companies that sell this type of equipment, requesting quotes and technical advice from THEM, the general public and even the people on this forum is really not the right audience for the kind of question you're asking.
 
Sceadwian
I'd like to see a copy of your FCC license to operate a radio station at that power... The transmitter+antenna being FCC certified does not give you a legal right to broadcast.
I think this installation is somewere well outside the USA, where the FCC has no jurisdiction.

Why is everybody asking about the license? What? You want me to upload a copy of it here? I'm only asking technical questions here and not discussing FCC regulations. The request has been submitted and whether they grant us a license or not, that's not my problem. I don't even care. I'm only in charge of the technical part of the matter. If no license is given, fine we are not buying what is in the quote. It is as simple as that. As a matter of fact, the license will just be given. I'm talking big entities here. It is government to government.

That aside, please contribute to this thread. I'm a long time reader here and I know there are well-educated people with lots of experience. I have limited knowledge myself regarding this, hence this thread.
Thanks

I believe that good advice has already been given:

Consider the location
Consider the surrounding topography
Consider the antenna and its mounting height

However you seem to have a fixation with transmitter output power and an unlimited budget to buy a transmitter.
You can use as much transmitter power as you want, but if there are big hills between transmitter and receiver, at VHF it will not work.

You seem rather coy about your location, I guess that this is some kind of "foreign aid" set-up in a third world country.
If you have $10k to spend on a transmitter, why not spend some $$$ on a consultant who can provide advice, probably similar to that which you are receiving here for free but choose to ignore.

JimB
 
The reason we're all asking is because, as I've said previously, you're going about it the wrong way.

You get your licence (or at least find out what it allows), THEN get equipment to match those conditions.

What's the point of spending time and effort sourcing gear that will be of no use?.

As I've previously said(with all respect to you Nigel), I don't think I'm going about it the wrong way! I'm actually learning new stuff by searching in my free time.
 
If your experience is this limited why are you even part of the process? You already have a moderately high powered transmitter, what you're looking for is a commercial RF amplifier. You should be contacting companies that sell this type of equipment, requesting quotes and technical advice from THEM, the general public and even the people on this forum is really not the right audience for the kind of question you're asking.

Because of my technical background, I have been given this task and I can't just refuse! And by saying limited experience: that was kinda of being modest you can say. I understand wireless communications theory and I'm not the best and haven't touched on FM broadcasting equipment.I already contacted companies and I'm kinda of checking my work here in my favorite electronics-related forum. If this is not the right place, then sorry my bad.
 
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I think this installation is somewere well outside the USA, where the FCC has no jurisdiction.

If I must say, I'm part of the coalition forces in AFGN, which is under USA control. You can say that we already have the license

I believe that good advice has already been given:

Consider the location
Consider the surrounding topography
Consider the antenna and its mounting height

However you seem to have a fixation with transmitter output power and an unlimited budget to buy a transmitter.
You can use as much transmitter power as you want, but if there are big hills between transmitter and receiver, at VHF it will not work.
Easily understood
You seem rather coy about your location, I guess that this is some kind of "foreign aid" set-up in a third world country.
If you have $10k to spend on a transmitter, why not spend some $$$ on a consultant who can provide advice, probably similar to that which you are receiving here for free but choose to ignore.
What did I ignore? I don't know where I ignored anything. I showed you guys what I got from one company I contacted and was waiting for some input like: Yes that should do the trick OR Nope that's not the way to go about it.
JimB

Thanks for being the most cooperative JimB
 
Who tasked you with this? Why can't you refuse?

My commander. My boss. Call it whatever you want. I'm obedient, why should I refuse? It is not like he commanded me to do a dangerous surgery to a dying man. I'm more into computers and electronics, but I can still do communications.



Anyways, I think that's all what I will get from this place. I thank everybody who contributed. And sorry if I misunderstood anything.
 
OK, lets recap - if you are still reading this thread.

Licencing is not a problem.

Money is no object, within reason.

You are in a remote location where the conditions are not ideal, there is an exisiting radio system which appears to have a very short range for the transmitter power (8km for 280watts from memory).

While not an expert in radio, you are the guy with electronics knowledge who has to try and improve the range of the radio to 60km.

This is what I would do if I were in your situation:

Examine the existing system
1 is the transmitter really giving the 280watts that everybody thinks it is?
Look at the meters on the front panel, what are they saying?

2 is the antenna and feeder cable in good condition?
Is the antenna made for the frequency in use?
Is the feeder cable a low loss type or just some junk which happened to be handy?
What are the meters on the transmitter saying?
Look at the reverse power indicator or VSWR indicator, what are they saying?

3 Can we increase the height of the antenna?
This is often an easy thing to do.

4 Use the RadioMobile software to do some signal strength predictions for your area, compare the theoretical prediction with actual results.
Try variations of antenna height, location and transmitter power.

5 Speak to the boss, tell him what you have found and any possible ways to improve the situation.


As for whether the transmitter mentioned in the quote is any good for you, I have no idea.
I have no experience of any broadcast transmitters.
What I do have is many years experience of HF and VHF transmission from my amateur radio activities, and I am forever being surprised at what does and does not work.
I have seen paths which should work no problem fail miserably, and paths which in theory stand no chance of working actually work fine.

?

JimB
 
Again though he doesn't need a transmitter, he's already got one, he needs an RF amplifier, that should be much cheaper than a full fledged transmitter. Many high power RF amplifiers require modest power input themselves especially in the range he's talking so that's something he should definitely be exploring as he's already got more than enough drive for a decent power amp.
 
OK, lets recap - if you are still reading this thread.

Licencing is not a problem.

Money is no object, within reason.

You are in a remote location where the conditions are not ideal, there is an exisiting radio system which appears to have a very short range for the transmitter power (8km for 280watts from memory).

While not an expert in radio, you are the guy with electronics knowledge who has to try and improve the range of the radio to 60km.

This is what I would do if I were in your situation:

Examine the existing system
1 is the transmitter really giving the 280watts that everybody thinks it is? YES
Look at the meters on the front panel, what are they saying? 282 watts
2 is the antenna and feeder cable in good condition?YES
Is the antenna made for the frequency in use?YES
Is the feeder cable a low loss type or just some junk which happened to be handy?Low lossWhat are the meters on the transmitter saying?
Look at the reverse power indicator or VSWR indicator, what are they saying? Not sure, didn't check
3 Can we increase the height of the antenna? Yes, we are planning to do that actually.This is often an easy thing to do.

4 Use the RadioMobile software to do some signal strength predictions for your area, compare the theoretical prediction with actual results.
Try variations of antenna height, location and transmitter power. Will try to do so
5 Speak to the boss, tell him what you have found and any possible ways to improve the situation. Sure

As for whether the transmitter mentioned in the quote is any good for you, I have no idea.
I have no experience of any broadcast transmitters.
What I do have is many years experience of HF and VHF transmission from my amateur radio activities, and I am forever being surprised at what does and does not work.
I have seen paths which should work no problem fail miserably, and paths which in theory stand no chance of working actually work fine.
That's bizzare!?

JimB

I can't be more gratefull JimB.
 
My commander. My boss. Call it whatever you want. I'm obedient, why should I refuse? It is not like he commanded me to do a dangerous surgery to a dying man. I'm more into computers and electronics, but I can still do communications.



Anyways, I think that's all what I will get from this place. I thank everybody who contributed. And sorry if I misunderstood anything.

Your limited to line of sight for normal VHF FM reception, so look at a topo map of the area and pick the tallest building, hill or mountain that you can get power to and build your comm shack there. 300W is plenty at the right location with a proper antenna to about 30 miles. I used old USMC VHF band radios many years ago for tactical comms out to 30 miles with just 25 watts. To get 60 miles range will take a major power upgrade (several KW) and a commercial antenna site.

https://www.electro-tech-online.com/custompdfs/2010/12/usmc-radio-ops-hdbk.pdf
https://www.electro-tech-online.com/custompdfs/2010/12/usmc-antenna-hb.pdf
 
As I've previously said(with all respect to you Nigel), I don't think I'm going about it the wrong way! I'm actually learning new stuff by searching in my free time.

As you've never explained the situation before, it's far clearer now - as an invading army you're presumably operating illegally?, so licence conditions don't apply.

Big transmitter, big aerial array, huge mast to mount it on - no problem.
 
As you've never explained the situation before, it's far clearer now - as an invading army you're presumably operating illegally?, so licence conditions don't apply.

Big transmitter, big aerial array, huge mast to mount it on - no problem.

I'm not invading anybody. We are there providing humanitarian help to those who need it. And I did explain it. I gave hints. Some got it, you didn't. And no we are not doing something illegally, we are dealing with the government. You don't just go pick a frequency and transmit it with 1000K watts.
 
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