Nate, Several years ago, I chastised ARRL Labs for failing to report the basic 2-way radio performance parameters of 12dB SINAD sensitivity, voice deviation limit, CTCSS deviation limit, and center frequency accuracy. I did not get a satisfactory answer, but I suspect that there is a reluctance to disparage the performance of name-brand Ham radios.
Nearly every Amateur 2m radio I have tested has CTCSS deviation far in excess of the EIA/TIA recommended level of 750 Hz, and that level is not adjustable in most radios. Alinco radios are the worst in this regard, because the radios are made with fixed resistors that set the CTCSS deviation level, which usually is two to three times the proper level. An Alinco tech stated that the exact level wasn't important, only that it was "high enough!" I own several Alinco radios that were delivered with CTCSS deviation above 1500 Hz, and I modified them to bring their emissions within industry standards. Such blatant disregard for industry-recommended deviation levels is certainly not limited to any one manufacturer! My ICOM IC-207H mobile radio needed adjustment to bring the center frequency and deviation within ICOM specs, but the model received rave reviews from users who didn't realize how imprecisely the radios were tuned at the factory. I realize that not every Ham has the test equipment to verify on-spec performance of a new radio, but I would like to see much greater care taken in fixing the critical performance parameters, before the radio goes out the door. Moreover, I would like "Amateur-Grade" to mean simply that the radio will operate on Amateur bands, not that it has been "dumbed-down" to eliminate important performance adjustments in the name of reduced selling price! 73, Eric Lemmon WB6FLY -----Original Message----- From: [email protected] [mailto:[EMAIL PROTECTED] On Behalf Of Nate Duehr Sent: Wednesday, March 14, 2007 5:27 PM To: [email protected] Subject: Re: [Repeater-Builder] Re: fixed-audio? On 3/14/07, nj902 <[EMAIL PROTECTED] <mailto:wb0emu%40arrl.net> > wrote: > Another post suggested checking the frequency response of your > repeater. Definitely - do that. Try it a various deviations. You > may be surprised at how ugly it gets. Sure would be nice to see ARRL labs do a shootout of repeater controllers with tests like this one... they spend days and days (and page after page) testing out $10,000 HF rigs... You'd think they could put some hard numbers behind the performance of the various repeater controllers out there every couple of years from the lab as a small article in the VHF/UHF month/edition. What kinds of tests would YOU like to see done in a "repeater controller shootout" article? Maybe someone could write one up and submit it... obviously a giant chart of features is probably a must-have for such an article, too... Nate WY0X
