XPR 4550 Power Supply Question

[kenwoodgeek]

Hi there,

First time posting in the Motorola forum. I have been offered a Motorola XPR 4550 trade for one of my Kenwood NX units.

I have a power supply that I have been using in my room with all my Kenwoods for the past few years without issue. It's an Astron RS-12A 12 amp power supply.

I have been told the 4550 takes 14 amps, and I am concerned about how it will work on a 12 amp power source. My 13 amp Kenwoods work fine on it, but I'm not sure about going one more amp up.

Would it work? Would it cause damage? Would I lose transmit power?

Thanks in advance!

 

[N4KVE]

In DMR mode, even in hi power, it will barely draw 6 amps. But in analog hi power, yes it will take the 14 amps. So use it in low power analog, or buy a supply that will continuously deliver 20 amps. Good to have a little extra.

 

[MSS-Dave]

A little misleading......

In DMR mode it WILL draw just as much current as in analog mode. However, as it is a TDMA digital scheme, the duty cycle is reduced. You will not see maximum current draw unless you have a peak reading current meter. Same goes for your RF output. In digital mode, the radio transmits on 1 time slot rendering a standard wattmeter somewhat useless. NXDN is a FDMA digital scheme which doesn't "pulse" the RF output or the current input.

Your RS12A is undersized for high power ops so I'd suggest at least 15. Digital does wonky things if you can't provide enough PEAK current to the radio.

 

[N4KVE]

Thanks for that info. I always knew the tx power showed half of what it it actually was in analog, but did not know it was the same for current draw, DMR vs analog. Good to know. Thanks.

 

[kenwoodgeek]

Got it, thank you. I only run analog. I will pass on this trade and put the radio up for sale.

 

[MSS-Dave]

Got it, thank you. I only run analog. I will pass on this trade and put the radio up for sale.

Which NX Mobile? 800 or 820? Might be interested.

Sent from my SAMSUNG-SGH-I337 using Tapatalk

 

[kenwoodgeek]

It's an NX-800H. High power 45 watt version. Just got it a week ago out of a trade. I cleaned it up and it works great.

I already have another 800H, and I can't use it on my portable base power supply, because that supply is only 10 amps.

Please make me an offer. If I can avoid the trouble of putting it on eBay and paying selling fees, that would be ideal.