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Transmitting from a "fixed station" on 467 main channels.


leszek

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When reading the current rules (https://www.ecfr.gov/cgi-bin/text-idx?SID=1934d854137d118c6e9796bfe9d17edd&mc=true&node=pt47.5.95&rgn=div5#se47.5.95_11763) I see the following in 95.1763:

 

 

 467 MHz main channels. Only mobile, hand-held portable, control and fixed stations may transmit on these 8 channels. Mobile, hand-held portable and control stations may transmit on these channels only when communicating through a repeater station or making brief test transmissions in accordance with §95.319©. The channel center frequencies are: 467.5500, 467.5750, 467.6000, 467.6250, 467.6500, 467.6750, 467.7000, and 467.7250 MHz.

So it looks like "fixed stations" may transmit on those channels without talking to a repeater - am I reading this correctly?

Further in 95.1767:

 

 

(2) The transmitter output power of fixed stations must not exceed 15 Watts.

 

So I can have a fixed station that transmits on 467 main channels without talking to a repeater with up to 15W of power yes?

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Staff is listing applicable definitions. channel and power data for reference when members reply in this thread.

_________________________________________________________________________________________________


Definitions under section 95.303 >

 

"Fixed station. A station at a fixed location that directly communicates with other fixed stations only."

 

"Base station. A station at a fixed location that communicates directly with mobile stations and other base stations."

 

"Control station. A station at a fixed location that communicates with mobile stations and other control stations through repeater stations, and may also be used to control the operation of repeater stations."

 

"Mobile station. A station, intended to be used while in motion or during halts at unspecified locations, that communicates directly with base stations and other mobile stations, and with control stations and other mobile stations through repeater stations."

 

ALSO -

 

95.1763 sub c  "467 MHz main channels. Only mobile, hand-held portable, control and fixed stations may transmit on these 8 channels. Mobile, hand-held portable and control stations may transmit on these channels only when communicating through a repeater station or making brief test transmissions in accordance with §95.319©. The channel center frequencies are: 467.5500, 467.5750, 467.6000, 467.6250, 467.6500, 467.6750, 467.7000, and 467.7250 MHz."

 

 AND -

 

95.1767 sub a 2 "The transmitter output power of fixed stations must not exceed 15 Watts."

 

 

===========================================================================

 

Staff Inquiry:  Do any members at MyGMRS operate a "fixed station" that communicates ONLY with other fixed stations simplex on the 467 mains?

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We are experiencing simplex use on our input. The first interfering party sounds like a group of 5 to 6 persons on 2 to 4 watt hand held radios, to move boats and other marine activity. Unfortunately they have chosen the travel tone for PL. I deactivated the travel tone and ignored them until we were hit with another group, running a 50 plus watt repeater output on our input. This could not be ignored, so contact was made and the interference ended. Now we turn our sights on the group moving boats as well as some local commercial abuse. I am surprised that 15 watts is allowed on 467, since that is about 4 times more power than HT's trying to key a repeater.

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The issue is that if simplex fixed to fixed operation takes place on a 467 main with 15 watts or less transmitter power (not ERP) and the simplex user happens to choose an active repeater input code, a repeater could be triggered each time the simplex communications on the 467 main take place.

IF anyone wishes to use 467 mains for simplex fixed op's, repeater activation code research should be done locally to verify that no repeater activation will take place.

This FCC rule stipulation may turn out to be a problem, especially in large metro areas, and may have been an unfortunate protocol to adopt. 

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One thing about "Fixed Stations" that no one is taking into consideration is that they must use directional antennas.  Fixed stations are not used for talking to either one another, or mobile units directly.  A Fixed station would be used as a "remote input" device to go into a repeater.

 

A Fixed station could be a small base station set up to talk and hear through the main repeater, not talking directly to mobile units, or it could be a similar setup to what I have in my basement on a Ham service repeater.

 

I have what would be considered a "Fixed Station" set up on an Emergency Alert System decoder box.  When weather alerts, Amber alerts, local emergencies, etc. are decoded by the EAS, it keys up a 2 Watt transmitter, going into a 7 element Yagi antenna, that points to the UHF Ham repeater linking hub about 7 miles away from me.  This unit doesn't receive anything, it is transmit only, one channel, directly into the repeater... a "Fixed Station".

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The way the FCC has this latest rule written is very poorly worded, and confusing. This is not what the original ruling meant, and I am going to contact the FCC about having the wording modified a bit to clear things up. (However, they seem to very much like muddy wording.)

 

Let me try to make the Fixed vs. Base station thing a bit more clear for beginners on the forum....

 

A repeater system is an un-attended automatic signal relaying device that picks up a communication on one channel, and relays it on another channel.

 

A Fixed station is a low-powered stationary device that is used to communicate with other units in its group through the one single repeater system which it is set up for.

 

A Base station is a high-powered station, likely using an omni-directional antenna at a high elevation, that can be used to communicate via repeaters, or directly with mobile and portable units, or other base stations.

 

A Control station is either a fixed, base, or mobile station that has the necessary tone generators or other signalling device to control the repeater system, as in turn it on and off remotely, without having to travel to the repeater site.

 

All of this terminology is left over from the business radio service. Typical UHF Business mobiles have 2 channels, "Main", which is through the repeater, and "Talkaround" which is simplex on the repeater's output frequency.  The business office/secretary likely has a "Fixed Station" on her desk, which is a 1 or 2 Watt radio with a small directional antenna on the roof pointed to hit the repeater.  In a typical VHF business system, all radios would be simplex, and the "Base Station" would need to have a tall tower on site to communicate with the mobiles.

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Fixed stations are not used for talking to either one another

 

Staff is listing applicable definitions. channel and power data for reference when members reply in this thread.

_________________________________________________________________________________________________

Definitions under section 95.303 >

 

"Fixed station. A station at a fixed location that directly communicates with other fixed stations only."

 

So which one is it?

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50W from a mobile station is allowed on 467 when talking to a repeater.

indeed, I would not have a problem with a licensed user using 50 watt's into the repeater, If he was 30 to 40 miles out and such wattage was necessary for repeater access. I would also expect he turn down his power if he is inside of the standard service area and even 25 watts would be excessive. Some people just think it's all about wattage.

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...

Definitions under section 95.303 >

 

"Fixed station. A station at a fixed location that directly communicates with other fixed stations only."

... ...

95.1763 sub c  "467 MHz main channels. Only mobile, hand-held portable, control and fixed stations may transmit on these 8 channels. Mobile, hand-held portable and control stations may transmit on these channels only when communicating through a repeater station or making brief test transmissions in accordance with §95.319©....

I don't see any ambiguity here.  It seems clear "Fixed Stations" may not talk through a repeater and may use the 467mHz main channels. 

 

If you are having trouble following, here it is in plain text. Per 95.303 a fixed station may only talk to other fixed stations. and per 95.1763 sub c, a Fixed station is not allowed to transmit through a repeater, though it may transmit on the 467mHz main channel.

 

The only issue is the definition of a fixed station provided by @jones. However, note that definition cites no actual rules and is in direct conflict with the citing posted by @PastorGary.

 

As far as I can tell, unless someone specifically needed to use a 467 mHz main channel for direct communications between fixed points, and limit their power to 15 watts, there is no reason to ever declare a station as a fixed station rather than a base station. My guess is fixed stations would only make sense in areas where no repeaters were available. general line-of-sirte communications were possible and, for some reason, no other channels were workable .

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We believe that members of the Commission review posts in the forum occasionally. IP addresses and hosting company details are visible to the staff.

Therefore, until such time as the Commission will publicly clarify their definitions, in an official update, GMRS operators could potentially accept that Fixed to Fixed voice communications, following the protocols in 95.303, 95.1763 sub c  and 95.1767 sub a 2, are permissible as long as encode CTCSS or DCS does not cause local repeaters to activate. As with all such communications, operators should use only the amount of transmitter output power and ERP to reliably communicate under your set of circumstances.

 

Recommendation from the Staff:  If you personally research all official available Commission information and choose to use the 467 mains, fixed to fixed, PLEASE research active repeaters in your area and choose frequencies that are not in use for repeater input operations, as a courtesy to others.  FM modulation capture effect could block repeater operations for some users.

https://en.wikipedia.org/wiki/Capture_effect

We hope that the Commission will address the vague definition situation soon and be very tech specific in any future rules amendments.

 

Disclaimer:  It is your personal responsibility to read and interpret current FCC Rules and make up your own mind as to how to operate your communications equipment, based upon the best information available. The Staff at MyGMRS furnishes this forum for registered and licensed members to exchange ideas and opinions and the Staff assumes no responsibility or liability for the manner in which information shared here is used by members.

 

 

 

`

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The answer to the original question is simply, NO. 

 

Without regard to power or whether it is mobile, handheld, or fixed....it is not acceptable to transmit on the repeater input channels (high side) in GMRS unless you are talking to a repeater.

 

14 posts before yours, many quoting various sections of Part 95, and all point to this being a loophole in the new Part 95 making transmitting simplex on the 467 mains legal under specific conditions at this time. What are you basing your rather broad statement on? Since the many of the participants in this thread have offered verifiable proof to support their position, perhaps you'd like to do the same. I am certain we'd all like to know what special rules have prompted you to issue this sweeping pronouncement.

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There has been a technical breakthrough in tin can communications technology that has doubled the range of this backup system. It's called - 30 pound test monofilament fishing line.  So. if anyone wishes to upgrade their system with more range and reliability over conventional string, this is the way to go...

 

https://www.ebay.com/itm/Berkley-Trilene-Big-Game-30-lb-Tested-440-Yards-Green-Fishing-Line/322488205512?epid=1700861574&hash=item4b15cb80c8:g:0s4AAOSwuspY94av

 

 

:D .......... :rolleyes: .......... :)

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