Watt Meters?

[roger460xvr]

What is a true peak reading meter? I have a Dosy pm 1000 that shows my Galaxy 959 doing 15 watts but my radio tech says he has it tuned and doing 30 watts. Why is the Dosy showing such low watts? Does the Dosy only show half of what its really doing?


Roger

 

[Tallman]

You want accuate? Get the bird meter. If you can't afford that this is next best: http://www.daiwa-industry.co.jp/radio/ham_e/products/meter/

He probably did not tell you it was peak watts. I don't think that board is capable of that power level.

 

[222DBFL]

Also there is the Telepost LP-100A. Good meter from what many have said. But again. Not cheap. Like Tallman said, Bird meters are good ones as well, but they aren't cheap either when you add in the freq/power reading slugs needed.
The Diawa meters seem to get pretty good reviews. Dosy meters are okay, and will do the job, but most aren't very accurate. JMO on those. I really like the LP-100A by Telepost myself and if I had the money would most likely have one of them. But that is just me. Also stay away from the MFJ meters. They are about junk.
Bird watt meter, Diawa, or the Telepost LP-100A would be your best bets. I know there are more out there, but these seem to rise to the top of most people's lists from what I have seen anyways. Hope you find one you like.
Only other meter I would suggest that won't break the bank and seem to work pretty good for the price is the Radio Shack SWR/power meters. I own one and it's always been pretty accurate. No it's not a bird meter, but they all have some degree of inaccuracy. JMO's. And I hope this helps and again, good luck finding one you like. But remeber most of the time, and I say MOST, of the time, you get what you pay for. Dosy meters have been synonymous with being over rated. Again. JMHO. Have a good day.

 

[Captain Kilowatt]

I have the Diawa CN-801 and the 801HP. Same meter except the HP model is rated to 3000 watts instead of only 2000 watts. Very good meters. You have to watch out for meters that claim to read peak or pep power. All peak reading meters require a power source to function usually in the form of a all wart power supply that plugs into the back of it and then to the AC wall outlet. Some meters only use power to light a meter lamp and despite having an average/pep switch on them do not read true peak power. All that switch does is switch a capacitor into the sample circuit to make the meter read higher. TRUE peak meters require a circuit that samples the power and properly drives the meter and this circuit has to get power from somewhere.

 

[roger460xvr]

What is a true peak reading meter? I have a Dosy pm 1000 that shows my Galaxy 959 doing 15 watts but my radio tech says he has it tuned and doing 30 watts. Why is the Dosy showing such low watts? Does the Dosy only show half of what its really doing?


Roger

thanks for the input ya so I guess my 959b from bells cb is not doing 30 watts,,,

 

[sonoma]

the best I have got out of a bipolar 959 is about 18 watts with my meters. you can get a little more out of a mosfet. I have never been one to worry about getting the high readings some get out of their meters. some techs ever re calibrate theirs so it will show more swing. i use a dosy and a pdc600 to check my radios with and it does just fine. also make sure you are going into a dummy load when you check the out put of the radio. going into a antenna will give you some false readings.

 

[543_Dallas]

thanks for the input ya so I guess my 959b from bells cb is not doing 30 watts,,,

Probably not. I have heard of people modifying them and installing dual finals. If that were the case 30 watts is possible.

I wouldn't worry about it too much if it's working. A watt meter is just a reference tool.

 

[Robb]

thanks for the input ya so I guess my 959b from bells cb is not doing 30 watts,,,

Probably is doing 30w.
I got the same results after peaking the TX coils on a 959 that has a MOSFET. Just because your meter cannot read peaks, it doesn't mean it isn't there.

Also, part of the test process with a meter is using a 50 ohm dummy load; not an antenna as the load. This can significantly change meter reactions to power readings.

 

[roger460xvr]

Probably is doing 30w.
I got the same results after peaking the TX coils on a 959 that has a MOSFET. Just because your meter cannot read peaks, it doesn't mean it isn't there.

Also, part of the test process with a meter is using a 50 ohm dummy load; not an antenna as the load. This can significantly change meter reactions to power readings.

Thanks Rob. I think you are very right on this idea because Screwdriver at Bells is supposed to be a very good technician. So its probably doing 30 but my Dosy is just not showing it. Thank you very much for the help. I'll purchase a dummy load and try it out.
Roger

 

[BBB]

I wouldn't worry so much about an expensive watt meter. Yes it is a good required reference tool to help keep an eye on your AM carrier so you don't blow up your PA section or amp, but it only shows part of the story.

Now a spectrum analyzer is the Truth Sayer when it comes to see how much power you can put out AND keep your signal in a usable bandwidth on a specific frequency. The beauty is that you will start to literally see your signal bandwidth increase (widen) as you start to overdrive your system. That increased over driven bandwidth and related off frequency spurs robs you of power on the frequency you actually want to talk on. Plus the unwanted spurs ultimately tax your amp if you run one.

I understand most casual CB operators will probably not fork out the cash for a spectrum analyzer, but the prices have really, really dropped over the last few years so they are now within reach.