700MHz Frequency List

[K6CDO]

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Another question, wouldn't the low power channels be simplex? They show as paired frequencies. Or would these be conventional repeaters installed in a command van-type vehicle for use at an incident scene?

The low power channels may be simplex or used in mobile / portable repeaters as long as the 2 watt limitation is observed.

Most portable radios natively operate at 3 watts. Mobile radios can be up to 35 watts. In response to a petition from the National Public Safety Telecommunications Council, the FCC has a rule making underway (FCC 13-40) in which (among other things) that 2 watt power limitation has been proposed to be raised to 20 watts effective radiated power. This would greatly increase the effective use of these channels.

 

[KB7MIB]

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Thanks all. I thought they were only simplex, but they can be used in low power portable/mobile repeaters as well.
Is there a prohibition from using the input as a simplex channel if there are no low power repeaters in use?

 

[Thunderknight]

Thanks all. I thought they were only simplex, but they can be used in low power portable/mobile repeaters as well.
Is there a prohibition from using the input as a simplex channel if there are no low power repeaters in use?

The biggest obstacle to that is you will find is a lot (all?) of mobiles/portables do not receive on the input side (e.g. can't receive 799-805). Therefore they can't be used for simplex on the input.

 

[KB7MIB]

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Ah, ok. I did not know that 700MHz radios didn't have receive capability in the input range.

 

[DaveNF2G]

Not many radios do simplex on repeater inputs in any radio service. The potential for interference to repeaters is too great, so the radios don't generally get built that way.

Ham radio might be the sole exception. Ham operators are expected to have the technical expertise to avoid interference with other users.

 

[KB7MIB]

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I've seen a few listings in the DB over the years where PS users have/had a 458 or 465 MHz frequency as a simplex channel, and I wondered if the same was done on 700 (or even 800) MHz with the low power channels.

 

[Thunderknight]

Not many radios do simplex on repeater inputs in any radio service. The potential for interference to repeaters is too great, so the radios don't generally get built that way.

Actually the inability to receive the "input" side on subscriber units is limited to 700/800. This is a function of RF design of the radio.
VHF and UHF radios can do it just fine because they are already designed to be broadband enough, as the pairings overlap with the total frequency range of the radio. (VHF has no pairing, so an input could be an output somewhere else, and in UHF, 453/458, 460/465, etc intermix across the split).

The reason 700 and 800 splits are reversed (700 is +30 MHz and 800 is -45 MHz for inputs) was done on purposes...it allows a common transmitter RF design...and keeps the required frequency range of the antenna together (794-824).

 

[DaveNF2G]

Wirelessly posted (Mozilla/5.0 (X11; Linux i686; U; en-US) Gecko/20081217 Vision-Browser/8.1 301x200 LG VN530)

I've seen a few listings in the DB over the years where PS users have/had a 458 or 465 MHz frequency as a simplex channel, and I wondered if the same was done on 700 (or even 800) MHz with the low power channels.

Some 458 and 465 frequencies are not paired with a 453 or 460 channel. They would be simplex only. For the ones that are normally paired, an agency would have to license both frequencies in the pair and then not put up a repeater.