MCS2000 Power Output

[Motradio]

MCS2K folks -

Just got an Ebay special UHF MCS2000. Was supposed to be a medium power radio, but showed up a 100-110W (L code) radio. Tossed it onto a power supply, added a couple of channels and noticed the 25amp supply hits current limit mode. So switched the mode to low power and it seems to be putting out about 30 watts or so into a dummy load but drawing about 20 amps (A bit unstable at that) at 13.8V.

This doesn't sound like something is working right in the finals of this radio, but this is the first one that I have ever had so unfamiliar with it.

Does this sound like a problem, seems like way too much current for the power out.

Thanks for any help.

Sandy

[d119]

MCS2000's are some of the most inefficient radios when it comes to PA output. I'd go through the PA alignment with your wattmeter and the tuner software.

[Motradio]

Great, nothing ever really works as planned

Still sure seems like a lot more current then should be possibly be used, would seem like high power would be in the 40 amp range for the radio to put out anywhere near 100watts. Almost seems like should be 50/60 watts for that much current (20amps), even with bad efficiencies with it the way it is working now in Low power mode drawing what it does.

Guess I need to get a service manual now.

Sandy

[Thomas]

I notice my 30 watt 900MHz MCS2000 draws 2-3 amps more than my 50 watt 440 kenwood radio. I thought it was strange but it could be anything. I have no watt meter to verify power output or swr on 900MHz but signal reports are good.

[Motradio]

Thomas -

I would expect the higher frequency radios to have a bit more loss, but also could be that it's putting out more power then 30watts I think either something is badly out of tune with the power amplifier in the radio or something is burnt. Almost seems like about 1/2 of the power output it should be for the amount of current. At 20 amps and 13.8 volts that's a draw of over 270 watts for about 30-35w output. I am going to take a look today at the soft pots and see what is in there that might give something away as to bad tune or a codeplug that installed that might not have been with the original radio that might mess up the tune.

Sandy

[N4KVE]

A hundred watt MCS2000 will not be working efficiently if the transmit is set too low. 60 watts is about it for the transmitter to remain happy. GARY N4KVE

[Motradio]

I don't think its a matter of power being set too low, the main concern is high current draw for very little output, say 20+ amps at 30 or so watts on low power, on high it current limits at close to 30 amps but kicks the limiter before I can get a reading. I did try the tuner software and on low setting it seemed to be optimal. I don't know about the configuration of the output but almost seems like its running on 50% output but with full current draw.

I also noticed an unstable amount of current draw when keyed, maybe 3-5 amps of fluctuation.

Sandy (on cell keypad, sorry if any typos)

[motorola_otaku]

Ebay special MCS, huh? Let me guess, "trumpsurplus" out of Arizona?

[Motradio]

Nope, not from them. Got a couple of MCS2000 speakers from them, but no radios. The guy that I got them from is solid and said no problem to return or repair.

Now on to the story, I just got in a nice Astron 50 amp supply and fired it up. Seems to put out 80 watts in HI and current is much less then the other POS Tenma power supply showed. One thing that I am now convinced that the POS 'Cross needle' meter is way off on current, by 5+amps when reading TX power.

The next suspect piece is the little Motorola Watt Meter, I have a couple of slugs and the both read the same, so I will be checking that too as it's been a long while since it's been used and seems like it may be reading a bit low.

I do really like the MCS2000, seems like a very nice radio and the few people I have talked to have commented how good the audio is. Waiting for a couple of VHF units and will get to work on figuring out how to cram a pair in my Excursion.

Thanks again for all the info and help to those that chimed in!

Sandy