CDM Power control

[jorenwendschuh]

What do the CDM (Waris base) mobiles use for PA temperature limiting? Is there a thermistor of some kind, is it a firmware timer, or something else? Looking to put a CDM into an intermittent duty repeater, but would like know more about the radio first.

Also - in the CDR Repeaters - are they 'stock' CDMs? or are they modified in some way that replacing one is not as easy as just swapping a 'standard' mobile in.

Thanks!

[35echo]

There is a temp sensing IC U5502 on the board near the RFPA to monitor thermal conditions and adj the tx power accordingly. It also has a timeout timer that can be programmed in the cps. The CDR uses standard CDM mobiles. Alot of people use low power mobiles for the rx radio in uni-diretional repeaters.

Regards,

Allen

[SteveC0625]

What do the CDM (Waris base) mobiles use for PA temperature limiting? Is there a thermistor of some kind, is it a firmware timer, or something else? Looking to put a CDM into an intermittent duty repeater, but would like know more about the radio first.

Also - in the CDR Repeaters - are they 'stock' CDMs? or are they modified in some way that replacing one is not as easy as just swapping a 'standard' mobile in.

Thanks!

Can't answer your question about the temp limiting, but I can tell you that the CDR's use stock CDM's except that the UHF Tx CDR gets the 1.5 PPM stability model of the CDM, same as a base station application. (I just finished working on a proposal using the CDR and got that info straight from Motorola.)

[jorenwendschuh]

Thanks guys!

Can't answer your question about the temp limiting, but I can tell you that the CDR's use stock CDM's except that the UHF Tx CDR gets the 1.5 PPM stability model of the CDM, same as a base station application. (I just finished working on a proposal using the CDR and got that info straight from Motorola.)

How does one distinguish a 1.5PPM stable model from other CDM's? Is it in the model number or FCC ID?

[SteveC0625]

How does one distinguish a 1.5PPM stable model from other CDM's? Is it in the model number or FCC ID?

UHF CDM750 AAM25SKC9PW1

The "PW" is the high stability model. All others will have "AA in those two positions.

The 1250's have the "PW" in the same position.

UHF is the only band affected.

[jorenwendschuh]

Thanks!