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Looking for a new transmitter

A

admcs13

Guest
I am in the process of looking for a new transmitter on a 100wERP station edu. station.

We currently have an exciter-only broadcast transmission (due to the failure of our xmtr).

Can any one recommend a new, reliable XMTR brand/model? Would we need to keep our exciter, or do new ones come with this built in? Also, would be interested in xmtr monitoring via LAN (though this is not a necessity) .

And finally, are newer ones as easy to install as plugging in the antenna and the audio feed from the processor (or exciter if need be)?

Someone has recommeded a broadcast warehouse 150watt.

Thanks for any help.
 
I'm not really that familiar with the Broadcast Warehouse stuff. It hasn't been around long enough to have a very proven track-record. In order to determine what size transmitter you need, you'll need to know your antenna gain and coax loss. Do you have a model # off your antenna? Also what size and brand is your coax, and what is it's length? Given those numbers we could determine you TPO (transmitter power output). I would say that your best bet is to look at the Crown Broadcast line. Unless you have a really high-gain antenna, the Crown FM250 would be an excellent choice. It is remote-able and Crown has a proven track record for reliability. This does come with a price though. If the cost was too high, I'd look at an Energy-Onix or a Nicom. With any of the above-mentioned models, you will not need an exciter. The install will be very easy...pretty much plug-and-play. Check with RF Specialties at www.rfspec.com. They should be able to give you a good price estimate.

-Chris Hall
www.reelaudio.net
 
> I am in the process of looking for a new transmitter on a
> 100wERP station edu. station.
>
> We currently have an exciter-only broadcast transmission
> (due to the failure of our xmtr).
>
> Can any one recommend a new, reliable XMTR brand/model?
> Would we need to keep our exciter, or do new ones come with
> this built in? Also, would be interested in xmtr monitoring
> via LAN (though this is not a necessity) .
>
> And finally, are newer ones as easy to install as plugging
> in the antenna and the audio feed from the processor (or
> exciter if need be)?
>
> Someone has recommeded a broadcast warehouse 150watt.
>
> Thanks for any help.

May I suggest calling BEXT. We just installed a new 1 kw unit that has complete computer interface capility. Very efficient, very clean with great audio. Price is moderate, not the cheapest but with excellent 24/7 customer service support. Sounds way better than the 10 year old Harris we replaced.

Rich KRDE
>
 
It is remote-able and Crown has a proven
> track record for reliability. This does come with a price
> though. If the cost was too high, I'd look at an
> Energy-Onix or a Nicom. With any of the above-mentioned
> models, you will not need an exciter. The install will be
> very easy...pretty much plug-and-play.

Broadcast Warehouse does make fine equipment. It's just that they are relatively new to the USA, so lots of people are not familiar with it. Crown is probably the most expensive LPFM stuff you will find, but many people feel it is well worth it. If you can afford it, I say go for it.

You will find that many companies, including Armstrong, BEXT and several other well known brands have a company in Italy called RVR build products for them. RVR is a well respected supplier whose products are good mid-range devices. We have some on the air right now. I've also had good experience from Nicom transmitters, which are also Italian.

I'd suggest finding a good dealer who can help you should you encounter difficulties. Most of this stuff is quite reliable, but you never know. A friendly person on the other end of the telephone who speaks your language is very reassuring.

We've purchased three transmitters from Superior Broadcast Products in Dallas. Like everyone else, theirs are re-branded from suppliers in Italy. I understand that they plan to start building some FM equipment state-side, but I don't know if that has happened as yet. They do assemble LP-TV transmitters in house. Benny Springer at Superior Broadcast has been very helpful to us. His number is 800-695-7919. I have no financial interest in their company, but I've found them to be easy to deal with. It might be worth a call.

The installation of these things is quite simple. As a previous post pointed out, you need to know the efficiency of your antenna, and the loss from your feed line and other extraneous sources. For instance, to get 100 watts ERP from a single bay antenna that is 50% efficient, you will find you need a transmitter that can put out at least 225-230 watts. Maybe more, if your feed line is long enough or made from high loss cable. If your antenna is unity gain, then with the same feed line, you might only need 130 watts or so. You must find out what you need power wise, before you purchase a transmitter, or you run the risk of buying one that is either way too big, or way too small. Either way, it is not an efficient use of your money.


Happy shopping,

Chuck
 
> I'm not really that familiar with the Broadcast Warehouse
> stuff. It hasn't been around long enough to have a very
> proven track-record. In order to determine what size
> transmitter you need, you'll need to know your antenna gain
> and coax loss. Do you have a model # off your antenna?
> Also what size and brand is your coax, and what is it's
> length? Given those numbers we could determine you TPO
> (transmitter power output). I would say that your best bet
> is to look at the Crown Broadcast line. Unless you have a
> really high-gain antenna, the Crown FM250 would be an
> excellent choice. It is remote-able and Crown has a proven
> track record for reliability. This does come with a price
> though. If the cost was too high, I'd look at an
> Energy-Onix or a Nicom. With any of the above-mentioned
> models, you will not need an exciter. The install will be
> very easy...pretty much plug-and-play. Check with RF
> Specialties at www.rfspec.com. They should be able to give
> you a good price estimate.
>
> -Chris Hall

Chris and company

Just had to reply about Crown. They are DEEPLY discounted to select religous broadcasters but for us "heathens" they are way over priced. I have found through on-going experience, their customer service is poor at best. After 18 months I never got any answer on how their SWR fold-back is set or how to calibrate it. Seems to be strictly 8-5, 5days a week and staffed by sales types. While BEXT is indeed Itialian, the quality is excellent and I am told the choice for CCU for back-up transmitters. The remote control is like having the transmitter screen menue in front of you anywhere in the world via the internet. I really like the new softstart feature. I frankly was suprised at the audio improvement as we run composite up the STL. The low end wasmuch better as was the stereo separation. Probably due to better differential phase response and a lower frequency PLL corner frequency. Just remember-- no matter wher it comes from or how much it costs -- how good is their customer serviceincluding replacement units or spare parts.

Rich KRDE


> www.reelaudio.net
>
 
Let's back up first.

1. What is your licensed power?
2. What was the brand and model number of the unit that failed?
3. What is the brand and model number of the exciter that you are using now?
4. What are you looking at in terms of budget?

Stay away from Broadcast Warehouse. Have friend who has one, would not make rated power (measured by an external Bird meter) Stay away from P-Tek. Underbuilt.

It sounds like what you really need is a power amplifier, not a complete transmitter. Your exciter is formulating the complete FM signal, at that point the signal merely needs to be boosted in power in order to make your licensed power.

However, if your exciter is many years ancient, and you have the budget, it might be prudent to replace it as well.

I have used the Henry line of power amplfiers with success, they need an external power supply, but the hook-up is not too difficult. I also have a higher power educational that uses Silicon Valley amplifiers, but I don't recall if they have a amplifier in your power range.
 
> I am in the process of looking for a new transmitter on a
> 100wERP station edu. station.
>
> We currently have an exciter-only broadcast transmission
> (due to the failure of our xmtr).
>
> Can any one recommend a new, reliable XMTR brand/model?
> Would we need to keep our exciter, or do new ones come with
> this built in? Also, would be interested in xmtr monitoring
> via LAN (though this is not a necessity) .
>
> And finally, are newer ones as easy to install as plugging
> in the antenna and the audio feed from the processor (or
> exciter if need be)?
>
> Someone has recommeded a broadcast warehouse 150watt.
>
> Thanks for any help.
> The Broadcast warehouse is an excellent choice.more bang for the buck and very well built.i run their dsp-x processor and just bought the all new dsp-extra..processor..if you have 4950.00 to spare Marti has their PNP 150 which is a all in one box and it is awesome, plug n play..it is made by BE...(broadcast electronics)..all digital xmtr and exciter unbelievable sound....
hand on to the exciter in case you ever need a spare.can't have enough redundacy in broadcasting....awhat type of antenna are you using????
 
My only experience with Bext is a 20-watt exciter (I think the model is XT-20) purchased new, that has been running 24-7 for several years. That thing is rock solid, sounds great and has had 0 problems. Can't tell you anything about their customer service, because I've never had to call them!


> It is remote-able and Crown has a proven
> > track record for reliability. This does come with a price
>
> > though. If the cost was too high, I'd look at an
> > Energy-Onix or a Nicom. With any of the above-mentioned
> > models, you will not need an exciter. The install will be
>
> > very easy...pretty much plug-and-play.
>
> Broadcast Warehouse does make fine equipment. It's just
> that they are relatively new to the USA, so lots of people
> are not familiar with it. Crown is probably the most
> expensive LPFM stuff you will find, but many people feel it
> is well worth it. If you can afford it, I say go for it.
>
> You will find that many companies, including Armstrong, BEXT
> and several other well known brands have a company in Italy
> called RVR build products for them. RVR is a well respected
> supplier whose products are good mid-range devices. We have
> some on the air right now. I've also had good experience
> from Nicom transmitters, which are also Italian.
>
> I'd suggest finding a good dealer who can help you should
> you encounter difficulties. Most of this stuff is quite
> reliable, but you never know. A friendly person on the
> other end of the telephone who speaks your language is very
> reassuring.
>
> We've purchased three transmitters from Superior Broadcast
> Products in Dallas. Like everyone else, theirs are
> re-branded from suppliers in Italy. I understand that they
> plan to start building some FM equipment state-side, but I
> don't know if that has happened as yet. They do assemble
> LP-TV transmitters in house. Benny Springer at Superior
> Broadcast has been very helpful to us. His number is
> 800-695-7919. I have no financial interest in their
> company, but I've found them to be easy to deal with. It
> might be worth a call.
>
> The installation of these things is quite simple. As a
> previous post pointed out, you need to know the efficiency
> of your antenna, and the loss from your feed line and other
> extraneous sources. For instance, to get 100 watts ERP from
> a single bay antenna that is 50% efficient, you will find
> you need a transmitter that can put out at least 225-230
> watts. Maybe more, if your feed line is long enough or made
> from high loss cable. If your antenna is unity gain, then
> with the same feed line, you might only need 130 watts or
> so. You must find out what you need power wise, before you
> purchase a transmitter, or you run the risk of buying one
> that is either way too big, or way too small. Either way,
> it is not an efficient use of your money.
>
>
> Happy shopping,
>
> Chuck
>
<P ID="signature">______________
Consolidated Corporate Radio S U C K S !!!!!!</P>
 
Quite an interesting range of responses and like everyone else I would like to share my opinions.

First, while many of these units are indeed "plug and play," one should not under estimate the value of hiring a professional broadcast engineer to at least review the installation and take some measurements to document that the station is legal. None of the transmitters mentioned have calibrated RF output meters so in order to set the power legally one needs a calibrated meter, such as a Bird 43 and a 50 ohm dummy load. The engineer will also measure the frequency with a calibrated frequency counter. While the engineer is on site he can look at other things, such as processing, the antenna system and grounding and will most likely be able to help out in other areas as well. You may be able to find a contract engineer who will give you a reduced rate if you are a non-com.

I installed a "name brand" 500 watt transmitter today. The factory test sheet gave the proper frequency and the unit's serial number and it was dated less than a week ago yet when I opened up the unit to inspect it I discovered it was set 2 MHz off of the station's frequency! What a disaster that could have been if someone had just plugged it in!

I've installed and been on call for nearly all of the models mentioned previously, and my favorite by far is Crown. The units are built to last decades, are simple to operate and sound good. I have installed six of these units in the last ten years at various stations, ranging in power from 35 watts to 500 watts, and all of the transmitters are still working fine. One 250 watt model sat in a wooden box at the base of the tower for four years with just a cooling fan in the summer and the readings never changed (this type of installation is not recommended but the station had no choice). I've found Crown's factory service to by excellent, even after hours. The only problem I have ever had with these units was with a five year old transmitter at a very low budget community station that get whacked by lightning so bad I had to send it back to the factory. I was expecting them to tell me that it was not repairable since there was damage throughout the rig, but they called to say that they would have it back in 24 hours! When I told them the sorry state of the station's financial affairs they offered to do the entire repair with used but fully warrantied parts for $68, a small fraction of what the repair was worth.

I have one Bext 300 watt unit in standby service. The quality of construction is excellent but the manual was poorly translated from Italian to English (the frequency change section is entitled "Contraved Weights")!!! Many of the drawings in the book are wrong too. The US factory service department didn't even know what one of the switches on the front panel did and could not give me the pin outs for the remote control connector (not in the manual of course).

One LPFM I know of has had nothing but trouble with their QEI 300w rig and the factory service has been very poor.

Silicon Valley makes great power amps and the factory support is excellent so if all you need is an amp go with them if they are still around (someone recently told me that they had been bought out).

I've found that with transmitters in this power range, you definitely get what you pay for so don't cut corners unless you really have to.
 
> I have one Bext 300 watt unit in standby service. The
> quality of construction is excellent but the manual was
> poorly translated from Italian to English (the frequency
> change section is entitled "Contraved Weights")!!! Many of
> the drawings in the book are wrong too. The US factory
> service department didn't even know what one of the switches
> on the front panel did and could not give me the pin outs
> for the remote control connector (not in the manual of
> course).

We're running a BEXT PT. Rock solid, really great sounding and never been off the air once. As noted the manual is poorly translated from Italian. Thankfully the Bext folks are great and everything is pretty straightforward that the manual isn't a big problem. The CROWN was simply too expensive to justify.
 
MY ANTENNA DATA

Hello,

Thank you so much for your replies.

ANTENNA
Jampro JSLP-1V, Vertically Polarized Antenna
ERP horizontal 0.100 kW
17m from the ground


TRANSMISSION LINE
Cableware
Foam Coax
Type: FCC12-50J
Lenghth: 15.3 meters
Nominal Inside Transverse Dimension: 1.27cm
Rated Efficinecy in percent for this length: 92.1%
 
Re: MY ANTENNA DATA

Do you know the gain figure for your antenna...it's not a current model in the Jampro database. I'm guesing it's probably around .995. If so, your TPO will be around 109 watts. That means you'd be fine with a 150 watt transmitter.

-Chris Hall
www.reelaudio.net


> Hello,
>
> Thank you so much for your replies.
>
> ANTENNA
> Jampro JSLP-1V, Vertically Polarized Antenna
> ERP horizontal 0.100 kW
> 17m from the ground
>
>
> TRANSMISSION LINE
> Cableware
> Foam Coax
> Type: FCC12-50J
> Lenghth: 15.3 meters
> Nominal Inside Transverse Dimension: 1.27cm
> Rated Efficinecy in percent for this length: 92.1%
>
 
Re: MY ANTENNA DATA

My gain is 1.0. How does this change anything?


> Do you know the gain figure for your antenna...it's not a
> current model in the Jampro database. I'm guesing it's
> probably around .995. If so, your TPO will be around 109
> watts. That means you'd be fine with a 150 watt
> transmitter.
>
> -Chris Hall
> www.reelaudio.net
>
>
> > Hello,
> >
> > Thank you so much for your replies.
> >
> > ANTENNA
> > Jampro JSLP-1V, Vertically Polarized Antenna
> > ERP horizontal 0.100 kW
> > 17m from the ground
> >
> >
> > TRANSMISSION LINE
> > Cableware
> > Foam Coax
> > Type: FCC12-50J
> > Lenghth: 15.3 meters
> > Nominal Inside Transverse Dimension: 1.27cm
> > Rated Efficinecy in percent for this length: 92.1%
> >
>
 
> First, while many of these units are indeed "plug and play,"
> one should not under estimate the value of hiring a
> professional broadcast engineer to at least review the
> installation and take some measurements to document that the
> station is legal. None of the transmitters mentioned have
(snip)

Off the top of my head, I don't remember if this applies to LPFM as well...but I *know* it applies to all Class A, B, C and D FM stations...

If you make any changes to your FM signal...you must perform a spectral analysis to make sure your signal still meets the FCC mask. This includes changing antennas, exciters/transmitters, RF transmission line, stereo pilot generators, and possibly even subcarriers (don't etch the subcarriers in stone, though).

Anyways, certainly installing a new transmitter would trigger the rule.

This analysis essentially requires a spectrum analyzer and generally they're too expensive ($15-$25k) for individual stations to own them. However, any broadcast engineer worth his or her salt will have one because the economies of scale make it worth it. Expect to pay somewhere between $500 and $1200 for the service & report, depending on market rates and how complex your setup is.



FWIW, I have come across many an elderly QEI at a college or similar low-powered radio station. Those suckers were built to last...but I've heard many horror stories from more recent purchases.

Crown tends to be hit or miss...some folks love 'em, some folks hate 'em. I think it depends heavily on what you're trying to do with the transmitter, but I don't have much personal experience with Crown.

I have a couple of Bext transmitters at some sites and they are indeed pretty bulletproof. The documentation and support is not so great...although the US office is trying hard to change that. Anyways, Bext is a very basic, low-cost, transmitter that will get the job done but you'll have to cook up a lot of workarounds to get (what I consider to be) basic functions like fail-safe RF muting and simple telemetry or remote control.

The Marti PNP series is pretty good, although they've got some quirks and aren't very tolerant of bad AC power. They have great remote control and telemetry options built right in, though...put one on a UPS with voltage regulation (which is a good idea for ANY transmitter) and you're in business.

My personal favorite is BE, but of course, they're the most expensive. Best support and best design I've seen, though. BE owns Marti and some of that trickled down into the design of the PNP series.

I saw Broadcast Warehouse's site at NAB last April...really cool stuff, especially their DSP-X processor. Not as sure about the transmitter but they seem to really "get" low power broadcasters' needs when I talked to them, so I'll wager they're pretty good, too.

Whatever you do - make sure you spec your new transmitter so that you are not consistently running at max power all the time. You can get away with running a 25w exciter at 25w all day...but running a 1000w transmitter at 1000w day in and day out will wear it down a lot faster than you might think. Give yourself at least 10% headroom, preferably 20%.
 
Re: MY ANTENNA DATA

> My gain is 1.0. How does this change anything?

If your gain is 1.0, then 100 watts at the input of the antenna gives you 100 watts ERP. You only have to take into consideration the loss from the feed line which I think you said was 0.92, so for every 100 watts you put in, you get 92 out the other end of the cable. In round numbers, that means you need 109 watts TPO to get your licensed ERP. Therefore a 150 watt transmitter would be appropriate for your needs.

Your license should say exactly what TPO you are authorized to use. You might want to take a look at it.

I'm not sure what you are using for feed line, but 0.92 sounds very efficient. Perhaps that's because your antenna is not very high. Is it 1 7/8 foam? Most 100 watt stations use 1/2 inch foam, and need 120-130 feet of the stuff. The usual loss for that is about 25-30 watts, depending on the manufacturer.
 
> Off the top of my head, I don't remember if this applies to
> LPFM as well...but I *know* it applies to all Class A, B, C
> and D FM stations...
>
> If you make any changes to your FM signal...you must perform
> a spectral analysis to make sure your signal still meets the
> FCC mask. This includes changing antennas,
> exciters/transmitters, RF transmission line, stereo pilot
> generators, and possibly even subcarriers (don't etch the
> subcarriers in stone, though).
>

That does not apply to LPFM stations. As far as I know, changing the transmitter is OK with no problem, as long as it is type accepted for LPFM. Not all low power transmitters are. There is a quirk in the LPFM rules that don't allow a manufacturer to "self certify" the transmitter.

If you change your antenna, tower, location, or anything else, you must file with the FCC. The rules are burried somewhere in Part 73.


> Anyways, certainly installing a new transmitter would
> trigger the rule.

As far as I know, it doesn't. The transmitter make and model are not a part of the LPFM licnese. The antenna type and model, HAAT, etc. are.

>
> I saw Broadcast Warehouse's site at NAB last April...really
> cool stuff, especially their DSP-X processor. Not as sure
> about the transmitter but they seem to really "get" low
> power broadcasters' needs when I talked to them, so I'll
> wager they're pretty good, too.

The DSP-X is a very good little box. BW has been selling transmitters in Europe for a long time. They are just relatively new to the US.

>
> Whatever you do - make sure you spec your new transmitter so
> that you are not consistently running at max power all the
> time. You can get away with running a 25w exciter at 25w
> all day...but running a 1000w transmitter at 1000w day in
> and day out will wear it down a lot faster than you might
> think. Give yourself at least 10% headroom, preferably 20%.

Very good advice....
>
 
We installed a 1000 watt Broadcast Electronics FM1C1 in March. At 15 grand it was probably the most expensive transmitter out there but they are definately built bullet-proof. As an example. the old transmitter (also a BE) went thru 2 rather large lightning strikes and survived. A fan failed and cooked the circuit board a few years ago, yet it faithfully continued to operate (albeit unreliably) until it was replaced. (The solder had reflowed all over board, which had turned a not-so-healthy black). Power didn't even drop! Only reason we discovered this happened was during maintenance visit some time later. (Let this be a lesson: temperature monitoring is there for a reason... use it!)

Experience with BE's technical support has been decent. If you're only a 100 watt station, however, they might be a bit out of your budget for what you get. I also noticed that setup wasn't as straightforward as it could have been. All in all they're a good choice if you can afford them.

I know Harris gives good discounts for non-comms, so you may want to check them out too.
 
Re: MY ANTENNA DATA

He's using half-inch foam cable, but the efficieny is about right. For 15.3 meters I get 92.7 per cent efficiency. 15.3 meters is only fifty feet. Hence to get an ERP of 100 watts he needs 108 watts into the pipe.
 
Silicon Valley is indeed still around, only the company name has changed to Delta RF engineering. Try DRFT.com
 
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