800 MHz vs 900 MHz CLB Stations

The following thread was recently posted on the msf5000 Yahoo! Group and was slightly edited for publication here:

I am looking for a good model number for a 900 MHz ham repeater and am finding conflicting information.

I have access to a C65CXB-7106AT. According to the MSF photo tour on Repeater Builder, this is a Compastation, 100-W, 806-960 MHz, digital capable, 120-vac, programmable squelch, 25 kHz, 3-channel, tone-remote, newer version repeater [Editor's note: some of this information is NOT correct in this e-mail]. See text from the Repeater Builder page below:

"Model Number Decoding:

The MSF model number follows the "old" format. This information is directly from the Digital-Capable Instruction Manual. Digital-capable implies the ability to run secure (encrypted) communications. Secure is NOT possible or available on 896 MHz stations; the Digital-Capable station for that band is called Analog Plus. (Motorola 896 MHz stations cover the 900 MHz amateur band.)"

Are all the 806-960 MHz stations considered "896 MHz stations" or do they come in two splits or more? If there are numerous splits, how do I determine I have an 896 MHz split?

Thanks for your help.

900 MHz stations (Motorola calls them 896 MHz) were either analog (Cx5CLB...) or analog-plus (Cx5GFB...). They use the "5" digit for 800-960 MHz, unlike the newer equipment that uses "5" for 800 and "7" for 900 (i.e. Spectras and MaxTracs). That's why the article says they follow the "old" format which was in effect until the mid to late 1980s.

It would seem that the UHF and 896 MHz stations were the only stations made with analog (CLB) controllers. These need the R1801 suitcase programmer.

800 MHz stations WERE secure-capable, hence they used the Cx5CXB... model numbers.

The 896 MHz stations were not capable of secure or encrypted communications, hence they're not fully "digital" in this sense. The GFB station does use a similar digital SSCB as CXB stations. Motorola chose the name "analog-plus" for the GFBs because they can only do analog communications but use the newer RSS programming technology.

So, an older EPROM-programmed station on 900 would be C85CLB... while a newer RSS-programmed station on 900 would be C85GFB...

The 800 MHz stations receive 806-825 MHz and transmit 851-870 MHz. There is only one band-split for 800.

The 896 MHz stations receive 896-902 MHz and transmit 935-941 MHz. These WILL accept programming and tune to the 902-903 MHz receive and 927-928 MHz transmit bands for amateur repeater use (25 MHz split). There is only one band-split for 896.

Of course, Motorola also made "SP" units that could transmit or receive at other frequencies. For example, an SP unit could be used as a base station, transmitting at the low end and receiving at the high end, which would be opposite of what a repeater would need.

The only way for sure to figure this out is to check the part numbers on the RF tray and/or the power amp. These would have different numbers for the 800 MHz or 896 MHz bands. You could also read the codeplug information with RSS, or key the station and measure the output frequency.

A follow-up posting added this bit of information:

There were many CLB 800 MHz MSF stations made for both conventional and trunking operations.

Here are some model numbers and applications:

C65CLB7106A/BT = 800 conventional repeater
C65CLB5103A/BT = 800 trunking repeater

C65CLB7206A/BT = 896 conventional repeater
C65CLB5203A/BT = 896 trunking repeater

The C65 stations are all 75 Watt models. There were also C85 stations at 150 watts.

Note the difference that a 7100 or 5100 series number is an 800 station whereas a 7200 or 5200 series number is an 896 station.

The difference between the 7XXX conventional and 5XXX trunking stations is primarily in the control tray where the conventional stations usually have a tone remote board or sometimes a DC remote board, the trunking stations have trunk control module.

The following model numbers are listed in the 896 MHz repeater manual, 6881064E70:

C65CLB5203AT 75w trunked repeater
C85CLB5203AT 150w trunked repeater
C65CLB7206AT 75w repeater tone remote control
C85CLB7206AT 150w repeater tone remote control
These are all EPROM programmed 896 MHz stations.

Any C?5CXB station is for the 800 MHz band.
Any C?5GFB station is for the 896 MHz band.
These are all RSS/PC programmed.