Gates Air Flex20 vs. Nautel NV20lt

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timinbovey
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Gates Air Flex20 vs. Nautel NV20lt

Post by timinbovey » Tue Sep 27, 2016 5:06 pm

The time has come to replace our aging RCA BTF-20E1. It's been chugging along for nearly 40 years. It's on life support.

Just trying to gather some opinions on current transmitter offerings. I've worked at the same am/fm combo for the last 28 years and have no experience
with new transmitters except for replacing our Harris MW5 on the AM with a new Nautel 2 years ago -- which has run trouble free since the day we turned it on.

At the moment we're considering the Gates Air Flex 20 or the Nautel NV20lt.

Thoughts and comments, advice and warnings welcomed. Also if you have experience with another current transmitter I'd appreciate any input.

Tim in Bovey

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kkiddkkidd
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Re: Gates Air Flex20 vs. Nautel NV20lt

Post by kkiddkkidd » Tue Sep 27, 2016 5:16 pm

I am very partial to Nautel... Their equipment is top notch AND they appear to be very stable financially. Which we can't really say for the other US transmitter manufacturers.

Having not installed a new anything other than Nautel in several years, I can't speak to Brand A or B's current products.

One of Nautel's minor peons is a regular on these boards so getting help with a problem is pretty easy.
--
Kevin C. Kidd CSRE/AMD
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level42
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Re: Gates Air Flex20 vs. Nautel NV20lt

Post by level42 » Tue Sep 27, 2016 8:25 pm

I've done 3 GatesAir Fax installs and 3 Nautel NVLT installs recently. I'm kinda underwhelmed with the GatesAir product. I've had numerous issues with both...the most recent being that one of the Fax boxes keeps losing its metering calibration. External wattmeter will show that we are putting out correct TPO, while front panel of transmitter will show about 4kw less...or 2kw more. Have to perform a factory calibration procedure each time. Very frustrating.

The NVLT is a good product, but I HATE that they are still using flash for the GUI. I think it is ridiculous that they have not moved to HTML5 and do not seem to be heading in that direction. A recent flash update broke all of the GUIs and required an update that took the stations off the air for a bit. I haven't lost any parts in the NVLTs, but the FAX boxes have lost several PA modules.

My dollar would be with Nautel based on experience.

Lee_Wheeler
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Re: Gates Air Flex20 vs. Nautel NV20lt

Post by Lee_Wheeler » Tue Sep 27, 2016 8:39 pm

I am similarly situated and at some point I am going to have to replace my circa '81 to '87 fleet of Continental and Harris transmitters.

I do a fair amount of contract installation work and my installations tend to track what my local RF Specialties shop is offering. For 20 years or so it was almost exclusively BE stuff but the local RF Specialties bailed on BE, perhaps with good reason, and pretty much exclusively sells Nautel so the last few years the installation work has been primarily Nautel gear. I have had a couple of opportunities to specify gear over the last year and it has been Nautel that I have recommended.

I do have a bit of a sour taste in my mouth with one of the Nautel VS2.5 installations that I have done and it has, from day one, been blowing PAs. The client has spent more replacing PA modules than they paid for the transmitter in the first place and Nautel keeps blaming it on bad grounding, their fall back position on everything. There is no better grounded station in the country than this one and I went so far as to add a 1/4 wave stub on the output flange a month ago and it blew the same modules again last weekend. The 4 year warranty doesn't seem to mean anything if they say it is lightning damage.

At the end of the day I am basing my recommendations primarily on who I figure is going to be around in another 10 years and my calls for parts at Gates Air lately, even for more current Vistamax products, have not been terribly fruitful. Gates Air no longer has the Harris Corp financial safety net in my mind and for that matter BE seems to have had some ownership turmoil as well. My gut tells me that Quincy, Illinois may soon go from being the world capitol of broadcast transmitters to not making any at all. I know absolutely nothing about their internal financial positions but I have seen companies come and go long enough to trust my instincts. They don't answer the phone at Sparta Electronics anymore.

The constant software updates get tiresome with Nautel but the I have a couple of VS300 exciters and a NV10LT as a four frequency backup for the group and they have generally worked well. I do have some trouble with the NV10LT wiping out the 3.6 GHz data link that feeds it audio if the TPO goes over about 4 kW. It doesn't appear to be cabinet radiation but then again the dummy load is a perfect match and the antenna isn't since it is cut to 98 MHz and we just force 93 to 104 MHz into it and the match is anything but perfect. It is tough to trouble shoot when the spurious stuff wipes out the programming and it has to be on the air to see it. Since my spectrum analyzer doesn't go to 3.6 GHz I don't have anything to see it with anyway.

My recommendations at my home stations, as much as I would like the ability to hop in the truck and drive to Quincy for emergency parts, will be to go with Nautel. For the most part I can plug them in, turn them on, and pretty much forget about them but the BEs and the Harris boxes that I have installed over the years haven't had much trouble either.

My 2 cents,

...Lee

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Deep Thought
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Re: Gates Air Flex20 vs. Nautel NV20lt

Post by Deep Thought » Tue Sep 27, 2016 10:38 pm

My experience with Nautel lately has been if it mounts in a rack, you'll probably have trouble with it (mostly third-party power supplies and PA devices) but if it is an old-school sits on the floor like a refrigerator-sized box you probably won't. They have been cutting costs on the "cheap stuff" and will probably abandon the lower power levels soon like they've done with AM. That said, you probably won't find a better >5KW transmitter anywhere, and if you are considering IBOC they are the only way to go.

Gates Air and BE are not the way to go unless you're prepared to buy two of everything and hope one works.

Forget about any of the "tier 2" and below manufacturers like Armstrong, although BW Broadcast seems to be serious about playing in the discount bin so you might look at them for things like low power backups.
Mark Mueller • Mueller Broadcast Design • La Grange, IL • http://www.muellerbroadcastdesign.com

davek
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Re: Gates Air Flex20 vs. Nautel NV20lt

Post by davek » Wed Sep 28, 2016 4:12 am

May I add a third suggestion, apart from Gates and Nautel?

Have a look at the Rohde & Schwarz THR9 Liquid Cooled series of FM transmitter.
https://www.rohde-schwarz.com/us/produc ... 45698.html

It's efficiency is comparable to the Harris/Nautel product. Depending on how your current transmitter is cooled you might enjoy good savings on the amount of electricity required to cool the transmitter; the liquid cooling system only uses a couple of hundred watts to drive the pumps and fans. With no blower it is very quiet, and it removes the need to worry about filtering outside air, or bringing humid air into the cabinet, or running expensive air conditioning if your cooling is closed-loop.

The pumps can be either mounted externally in it's own rack, or internally within the transmitter cabinet. Personally I prefer external pumps for ease of maintenance access.

I've had experience with digital television version of this transmitter and can vouch for their reliability, excellent construction quality, and ease of installation. As a company Rohde & Schwarz seem to be very well established and offer a commitment to fully support their products at least 10 years after end-of-life. I'm not associated with R&S in any way other than being a happy customer. :)

TPT
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Re: Gates Air Flex20 vs. Nautel NV20lt

Post by TPT » Wed Sep 28, 2016 7:13 am

Happy with my Nautel 10NVLT--the critter even kept humming along with one phase down (just dropped to half power--I put the backup kilowatt on, though, to be safe.) Haven't had any real problems with my VS-2.5. Did have a VS1 loose display and internet connectivity (and apparently a module) but that's a bad site--antenna on a tall AM tower,grounding, etc.

On the other hand had a Gates Air 5 arrived with three phase installation instructions written for European 440 volts (strange it wouldn't work out of the box) and has the same power output metering weirdness described above (box thought it was overpower, so reduced power down to a few watts) Exciter been back twice to be finagled. Gates Air: Keeps you cool in the winter, warm in the summer...

taylorengineer
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Re: Gates Air Flex20 vs. Nautel NV20lt

Post by taylorengineer » Wed Sep 28, 2016 7:45 am

I work for stations which have both the Flex and GV series Nautel radios. You can't go wrong either way!
We have two Flex40s and a FAX20. The FAX has been with us for around 4 years with only a hard to find/replace fuse lost. The Flexivas have been around for 2 years and have never lost any parts but have needed power recycled a couple of times after utility power mayhem.
One Nautel has lost a RF pallet after 2 years of operation - the other, none. Firmware updates are not for the faint of heart - I have only had a single update session go smoothly. Usually an update will stall and simply need to be restarted - one trashed the OS had required replacement of the CF card in the controller.
The older GV40 has developed a touch screen issue which is unresolved at this point. I currently have no control from the local touchscreen - I have to use the controller buttons or the remote GUI.
We still have a couple of tube transmitters but those will be gone as soon as budgets permit. It is getting hard to find decent tubes, especially rebuilts. As others have pointed out, a solid state design will dribble out at least some RF no matter what happens, short of a total power failure, and that makes their purchase worth it alone.

lewiscallaway
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Re: Gates Air Flex20 vs. Nautel NV20lt

Post by lewiscallaway » Wed Sep 28, 2016 9:09 am

I second timinbovey about the software updates. The Nautel is rock solid, but I haven't had a good experience upgrading the software. It's kind of a "if it ain't broke don't fix it" deal. Ours wiped out the computer and we had to buy an all new board.
Otherwise, it's a great transmitter!

taylorengineer
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Re: Gates Air Flex20 vs. Nautel NV20lt

Post by taylorengineer » Wed Sep 28, 2016 12:00 pm

Lee_Wheeler wrote:
I do have a bit of a sour taste in my mouth with one of the Nautel VS2.5 installations that I have done and it has, from day one, been blowing PAs. The client has spent more replacing PA modules than they paid for the transmitter in the first place and Nautel keeps blaming it on bad grounding, their fall back position on everything. There is no better grounded station in the country than this one and I went so far as to add a 1/4 wave stub on the output flange a month ago and it blew the same modules again last weekend. The 4 year warranty doesn't seem to mean anything if they say it is lightning damage.



My 2 cents,

...Lee
Curious about your transmitter story, Lee.
Nautel has specific grounding designed for their transmitters...at least the GV40. It is a single point on the back of the cabinet that is isolated from the cabinet. They tell you ground at this point only. (Obviously, the transmission line is also grounded.)
I have always run a piece of 4 inch strap to the cabinet(s)but installed my transmitter as Nautel recommended. I have had no lightning issues and know of no other stations suffering from lightning damage on a regular basis.
If it is not a grounding issue what do you think is causing the problem?

Lee_Wheeler
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Re: Gates Air Flex20 vs. Nautel NV20lt

Post by Lee_Wheeler » Wed Sep 28, 2016 12:36 pm

taylorengineer wrote:
Curious about your transmitter story, Lee.
Nautel has specific grounding designed for their transmitters...at least the GV40. It is a single point on the back of the cabinet that is isolated from the cabinet. They tell you ground at this point only. (Obviously, the transmission line is also grounded.)
I have always run a piece of 4 inch strap to the cabinet(s)but installed my transmitter as Nautel recommended. I have had no lightning issues and know of no other stations suffering from lightning damage on a regular basis.
If it is not a grounding issue what do you think is causing the problem?
Pictures make it easy:
Main Ground in Transmitter Room.jpg
Bonded to tower ground, the AM ground system, and the isocoupler. There is another 1/4 wave stub at the input to the isocoupler.
VS 25 Ground.jpg
The braid is silver soldered to the strap.
Stub on VS 25 Transmitter.jpg
1/4 wave stub at the transmitter output.
Surge Protector.jpg
A.C. line surge protection.
They have gone through 8 or 10 pallets at this point and they are always 1 and 2. My gut tells me there is a problem with the combiner.

...Lee

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kkiddkkidd
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Re: Gates Air Flex20 vs. Nautel NV20lt

Post by kkiddkkidd » Wed Sep 28, 2016 3:29 pm

I would highly recommend boxing that little dumpling up and sending it back to the factory for repair. I have 2 VS2.5's and a couple VS1's and none have ever lost a pallet outside of a MAJOR lightning strike.

Do you have Jeff Welton's contact info?

Later,
--
Kevin C. Kidd CSRE/AMD
WD4RAT
AM Ground Systems Company
http://www.amgroundsystems.com
KK Broadcast Engineering
http://www.kkbc.com

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Deep Thought
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Re: Gates Air Flex20 vs. Nautel NV20lt

Post by Deep Thought » Wed Sep 28, 2016 8:24 pm

That braid is highly reactive at "lightning frequencies". I would replace it with at least a 2" copper strap.

Also, how is the tower itself grounded? The AM ground radials are not enough.
Mark Mueller • Mueller Broadcast Design • La Grange, IL • http://www.muellerbroadcastdesign.com

taylorengineer
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Re: Gates Air Flex20 vs. Nautel NV20lt

Post by taylorengineer » Thu Sep 29, 2016 7:41 am

Lee_Wheeler wrote:
taylorengineer wrote:

They have gone through 8 or 10 pallets at this point and they are always 1 and 2. My gut tells me there is a problem with the combiner.

...Lee
What does Nautel tech support say about the same modules failing every time? Do they give a reasonable explanation for why the same two pallets are the only ones affected by "improper" grounding?
Is there visible lightning damage to the pallets?

Lee_Wheeler
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Re: Gates Air Flex20 vs. Nautel NV20lt

Post by Lee_Wheeler » Thu Sep 29, 2016 4:42 pm

The station in question is about 250 miles away from me and I have not been directly involved in the conversations and I have not actually had the opportunity to replace any of them myself. Based on the verbal description I am going to say that they just short out without visible damage but I can't swear to that. I did the installation of the VS2.5 and a J1000 and then did a follow up installation last month of a VS1 for a translator. I actually had no idea that they had gone through so many amplifiers until they told me when I was there for the translator installation. I knew of one pair that went early on but since I don't have day to day involvement I never heard back after that. Nautel apparently did suggest the 1/4 wave stubs as the sure fire cure.

I as pretty appalled when I learned the extent of the problems.

To Mark's question, the tower is a series fed AM but the base strap is bonded to rods as well as the radials, one set at the tower base and another set next to the service entrance where the neutral bond is made.

...Lee

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