What to do about this?

We’ve been informed by a local amateur radio group that they are testing and plan to deploy an ATV 900mhz AM & FM repeater. They provided us the following info:

the first am atv transmitter will be centered at 907 and take up from 902 to 908 mhz and the new fm digital one will take up around 18 mhz and will be centered around 917 and run from 908 to 926 mhz we are losing a bit of power from the combiner so its only running 900 watts in to the 1 1/4 feed line but the 10db gain antenna will sure help


We understand they are governed by FCC part 97 but is there anything we can do to prepare for or minimize interference from this device?

Are they within their rights to do this?

try a different polarity then they are running. otherwise your screwed. are they really running 900 watts?

Can I really run a different polarity though if I have 4 other towers within 10 miles of this place?

All my towers are running 900Mhz integrated APs.

Since the interference source is in the same band you are going to be hosed I think, no matter what polarity. That much power is going to make your AP’s deaf to the rest of the world. Maybe someone will say otherwise, but I think you are hosed.

integrated AP’s are only H-Pol i thought. even so. 900 watts will overpower everything. i would check the FCC rules and regs make sure theyre allowed to broadcast with that much juice.

We don’t know how many watts is reaching the antenna, if several hundred feet of feed line then maybe only about half the 900W is making it.

Certainly they are within the FCC rules, because they are licensed by the FCC to use the band, and you are not, you must accept any interference caused by them, and what sucks is you cannot cause interference to them.

You just need to wait until the ATV repeater goes on line, and see if you can work around it. If not your option is to change bands.

They can run up to 1.5kw pep, with no EIRP restrictions under fcc rules.

Alabam wrote:

They can run up to 1.5kw pep, with no EIRP restrictions under fcc rules.



does that come with a side of lube?
VLAN1 wrote:
[quote="Alabam":1fhi6jgu]
They can run up to 1.5kw pep, with no EIRP restrictions under fcc rules.



does that come with a side of lube?[/quote:1fhi6jgu]


definately not! :lol:

I just went through this on our tower. They are totally within their rights as they have a license and we don’t.

We were able to work around it as they did not deploy the digital channel. If they had we would have lost the entire 900 band.

Plan on moving to another band or abandoning that tower.

What exactly is the function of their deployment?

Amateur TV Repeater.

TV repeater for what purpose though?

http://www.dxzone.com/cgi-bin/dir/jump2.cgi?ID=2949

I’m not seeing where the benefit to anyone outweighs the damage of shutting down hundreds of not thousands of Internet connections.

I won’t lie, I am not a HAM fan. The HAM’s in my area have towers that could topple at any moment and their arrogant attitude towards Part 15 ISM use is sickening.

IMHO WISP’s should ban together to get the FCC to reign in HAM operators sharing the ISM. They shouldn’t have a “right” to use it anymore than we do and should be restricted to the same EIRP we are.

The federal government provides millions and millions in RUS loans and grants for people like us to bring broadband to the rural areas. I have to rely on 900mhz for most of my customer base due to tree coverage.

The thought that a HAM could come to my area and essentially shut off 500+ 900mhz customers doesn’t sit right. And for what? so they can read a bulletin or broadcast off an antique Amiga computer?

Give me break.

Good points about these guys. I agree - they should have power restrictions same as us.

But hey - don’t knock the Amiga. I was raised on a Commodore 64, and followed it with the Amiga.

It was way ahead of its time - great multitasking at only 7mhz!

:slight_smile:

jwcn wrote:
I'm not seeing where the benefit to anyone outweighs the damage of shutting down hundreds of not thousands of Internet connections.

I won't lie, I am not a HAM fan. The HAM's in my area have towers that could topple at any moment and their arrogant attitude towards Part 15 ISM use is sickening.

IMHO WISP's should ban together to get the FCC to reign in HAM operators sharing the ISM. They shouldn't have a "right" to use it anymore than we do and should be restricted to the same EIRP we are.

The federal government provides millions and millions in RUS loans and grants for people like us to bring broadband to the rural areas. I have to rely on 900mhz for most of my customer base due to tree coverage.

The thought that a HAM could come to my area and essentially shut off 500+ 900mhz customers doesn't sit right. And for what? so they can read a bulletin or broadcast off an antique Amiga computer?

Give me break.



Hams do not share the band with part15 devices, they share the bands with part18 ISM devices. Hams must accept interference from any Part18 device, ISM devices are primary users of the band. Part18 devices do not receive, they radiate rf only. This was the case in 1985 with the band was allocated to Region 2.

Then along came Part15 devices, these devices are unlicensed and transmit rf at low wattage. These devices trashed up a previously quite band. Most hams have had problems from Part15 devices. Cordless phones, baby monitors, wireless garage door openers, radio controlled toys, cordless speakers,tv's, and countless other modern electronic gadgets. These devices cause hams interference from 50mhz to 240ghz, no wonder hams dislike them. Just about any device with a microprocessor and emits rf is a Part15 device anymore, even computers.

Motorola Canopy is not a ISM device, it's a Part15 device, a unlicensed device, limited to less that 1 watt transmit power. Just like all Part15 devices they must accept any interference from and can't cause harmful interference to any licensed users on the band.

I guess you researched the rules before you spent all that money and knew, or should have known you were deploying a part15 device, just like a cordless phone, or a garage door.

By the way hams quit using commodore computers in the 80's.

Where do you live I've always wanted to put up a ATV repeater....:lol:

Just kidding....

I agree the FCC should create a licensed spectrum with coordination for small wisp's.

That is not the point I am making. The point is, HAM’s should not be allowed to use ISM frequencies for anything but emergency communications during an emergency. Their license is far too general with too many loose ends.

Can you give some examples of part 18 devices?

jwcn wrote:
That is not the point I am making. The point is, HAM's should not be allowed to use ISM frequencies for anything but emergency communications during an emergency. Their license is far too general with too many loose ends.

Can you give some examples of part 18 devices?


There are hundreds of part18 devices, these devices radiate RF, but do not receive RF. ISM "industrial, scientific and medical".

A microwave oven, MRI machine, ultrasonic equipment, shrink wrap machines, neon lights, computed tomography (CT), UPC code readers, weather stations, alarm systems, security systems, and countless other devices that transmit rf, but do not receive it.

The Ham's operate 900mhz band under Part 97, WISP operate under Part 15 rules. If ham's use spread spectrum modulation then they are limited to 1 watt. Ham's are required to use only the amount of power necessary to maintain communications. They can use up to 1500 watts pep, but i do not know of any 900mhz stations getting more that 500w to the antenna.

Hams use the frequencies on a non profit basic, WISP are there to make money. The FCC seen fit to give WISP parts of the trash bands, blame the fcc not the hams. The rules are what they are, hams were using the band when wisp came along, if not for hams proving the band could be used for more than ISM devices, there would be no wisp on 900mhz and higher bands today.

I have a wisp as my internet provider, I do work for a wisp, I've been a ham for 25 years. I would be pissed if a ham shut down my internet cause cable or dsl is not available. You certainly can petition the fcc for proposed rule making, and try to change the rules, or you can get your ham license and have a voice to keep hams in your area from putting up a 900mhz repeater.

I am a ham, and I manage a wisp…


Tough being a wisp isn’t it? I grin and bear it myself because I understand the band restrictions. Don’t like how the 900 spectrum is trashed? Deal with it and move on… go licensed.

Most of the guys I work with are hams too. The old timers curse part-15 users, because they trash the spectrum. These guys remember when the part-15 spectrum was still regulated to part-97 use. When the FCC opened it up for part-15 use, they got all bent…and are still bent today.

I feel your pain, but again… move into a different band all together.

That is easier said than done. Is there a licensed band suitable for NLOS deployment? Better yet, one that the mom and pop WISP’s can afford?

Now I am interested in the 1watt DHSS limitation. What type of modulation is used at the higher powers?