How about a good
The most controversial accessory in Ham radio? Liberal, conservative, accurate, enhanced, embellished, average, peak reading, swinging peak, putt-putt, professional, production standard- what is the real story about SWR/wattmeters?
Hams talk on the air all the time about wattmeters. Old stuff like Heathkit, Nye Viking, Collins, Swan, Drake, etc. New MFJ, Palstar, Vectronics, Autek, Bird, Coaxial Dynamics, Diawa, Kenwood - and on and on. Everybody says theirs is accurate on the frequency that gives the highest reading. What is the real story? I only know about my experiences and conclusions with the inexpensive putt-putt meters and the inexpensive professional meters.
I then purchased an MFJ wattmeter. WOW! another mo-power boost of about 25%. I believe this is called inverse attenuation. Hmmmm? Perhaps a few of these products in series could produce the subject for an article about inverse attenuation in an upcoming issue of QST - say April 1 of any year. No, not really.
When I spoke with engineering types about the WOW! mo power, they assured me that one Bird meter was adequate and marketing had nothing to do with how they calibrated or set the one Bird wattmeter, used as a standard to set other Birds used in production line calibration of putt-putt meters. No error checking for their measuring instrument standard existed.
Well, that's about all there is for a standard when making putt-putt wattmeters. Wattmeters are measuring instruments. Mass producing measuring instruments requires diminishing tolerances down the reproduction line. If a terribly expensive HP instrument up the line is a standard for manufacturing the standards used in production lines to check the Coaxial Dynamics 81000A and Bird model 43 wattmeters and those are used as production line standards to make the putt-putt meters, then, ya-know, all of those accuracy tolerances (in-accuracies) need to be added up.
We received these and I put them out of the way until it was time to ship the first prizes. It is an attractive meter, heavier materials than putt-putt meters I have handled. So, I pulled one to be photographed and reviewed for an article in our review section. At the bench, using the Alpha 87A for power, I could not get a peak reading at any power level. It actually gave a lower reading for peak than for average. Well, trying to find the problem I removed the new meter and hooked up the meter we have been using on the bench in it's place. Worked fine, giving proper peak readings. Tried the new one again. Nope. Back in the box and set aside.
The second meter worked fine, gave proper peak readings at low power. At 1000+ watt power levels it had a high SWR situation that tripped the fault circuit in the 87A repeatedly, indicating a cold solder joint. Set aside.
The third unit demonstrated the same problem as the first. Next morning I tested all three units again. Same result. Three randomly selected units failed to produce satisfactory results. I returned all 10 units to the factory and sent email explaining the situation.
Hmmmmmmmmm, maybe I should call the ARRL and try to get the the one they tested that works and review it. I'm sure it was randomly selected by the factory through the normal ordering process for the ARRL review and test, just like our meters were.
I told him we like the nice looking product and had hoped to promote it and use 10 in our promotion. Paul said, "As the Russians say, 'tough shitsky'. I don't want to do business with you. You must be incompetent." I said, "Because we couldn't make your meters work?" "Yes."
Please don't jump to any conclusions by his "tough shitsky" or "incompetent" statements as Paul was directing those to me and we, not you, as in you people, right? Well OK then, it's settled, he did not mean you people or we Hams must be incompetent. He only meant you and we, as in me and us, I guess, because I and me and we or us couldn't make the wattmeters work properly.
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Well, I did call in Autek's time slot to inquire about buying 8 or 10 units for our Sweepstakes. The person I spoke with, Bill, displaying his superior human relations and marketing skills said, "I'm not interested "and hung up. Huhhhh? I guess I won't be buying wattmeters from him. How about just buying more Goldline microphones or perhaps a few of the new antique microphones Heil Sound now has available?
Time running out
After a few days I re-contacted them. They finally sent an email advising price and availability. Three weeks to ship their Bird 43 equivalent? One more call. I asked about stocking distributors or dealers, "none in the Wireless industry". None? "None."
One last chance
Take a look at the Coaxial Dynamics pictures. It has a graphical big improvement, a big white face taught band meter. We have been using the Coaxial Dynamics in series with a Bird 43 for a couple of years on our test bench. Both are fine meters. Slugs are interchangeable. http://www.coaxial.com/products/81000.htm
It appears that it is not economically feasible to produce a wattmeter that satisfies all and sell it at the prices demanded by the market today, $80 to $125. Consequently, because it can't really be done, some quality compromises and frustrations occur.
So, how about a good wattmeter? Mo power types are available everywhere. Good, you can get with professional field units from Coaxial Dynamics (best) or Bird (next best). Excellent, high accuracy lab instruments? - Probably not, too expensive.
Bob Hutchinson, N5CNN
If you would like to publish an article here contact Bob Hutchinson, N5CNN.