Gentle people, I've been sitting quietly on the sidelines, watching this thread progress. And I think that maybe it's time for me to jump in with my own opinions on digital vs. analog. (Whether it be P-25 or D-Star)
Although I'm usually very open to newer technology, this digital (or better said, "digitized") voice thing has me very concerned. As a public safety worker, I shudder to think that maybe some day I might need assistance and call for back-up, only to have my meaning misunderstood because a few syllables were dropped because of the CODEC. For example: how many people have told someone else on their cell phone that "you sounded like you just went under water?" (Especially with Nextel?????) Or suddenly had your call discontinued - with no prior warning/indication? As ham radio operators, one of our missions is to pass critical traffic... we cannot fulfill that mission if the traffic cannot be properly received in the first place, whether it is because we cannot ourselves discern the message or it is obscured because of "artificial" means. My question is: why make it more difficult on ourselves to accomplish this mission by adding another layer of fallibility into the picture? Now in regard to the testing/repairing these D-Star systems... I didn't become a ham until later in life, although I've always had an interest in radio. But since I have, I continue to strive to be more than just an "appliance operator"... I need to be able to understand how it works, and if within my means, troubleshoot and/or repair it. Based on the earlier statement that the only way to test/repair these stations is to "box and ship" it back to the manufacturer, I feel we as Amateurs are taking a huge step backward, both for ourselves and for our hobby. I also feel we are doing the Amateur Radio Service itself a huge disservice, since one of the basic tenets of the Service itself is to "Expan(d) the existing reservoir within the amateur radio service of trained operators, technicians, and electronics experts." [Part 97.1(d)] OK, flame-proof suit on... You may fire when ready, Gridley! 73 de Mark - N9WYS -----Original Message----- From: Repeater-Builder@yahoogroups.com On Behalf Of Steve S. Bosshard (NU5D) Sent: Thursday, September 20, 2007 1:53 PM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Making room - testing DSTAR I take care of a pretty large EDACS system. There is a simulator built into my COM120B just for EDACS and LTR - even decodes pocsag paging. This is never used in setting up the base station/repeaters. The procedure uses simple deviation and receiver tests. Same with subscriber units - most (but certainly not all) problems can be caught in conventional mode. On the repeater receiver a sniff point on the discriminator output allows basic receiver testing. This does not simulate DSTAR but gets to a go/no go point. Kind of like the first DPL - I had to buy an aftermarket board and wire it to my CE50 service monitor - would encode and if the light went out on receive - would decode as well. I doubt any manufacturer will make a test set for a low volume product because there are not enough folks wanting to pay for a DSTAR tester. Next problem - if the thing is broke - I am not gonna go probing around surface mount chips with my simpson and weller - better to box and ship. Anyhow that another 2 cents - might make payroll if this keeps up... 73, Steve NU5D Mike Morris WA6ILQ wrote: > > And one more point - and it's a major one.... > > You can get P25 test equipment. > > Show me one piece of test equipment - an IFR, an HP, a General Dynamics > (the folks that made some of Motorolas R-series of service monitors) > or any > other test equipment manufacturer that makes a dstar tester. Not even > the manufacturer has one. > > So haw do you verify that a dstar system is actually working right? Yahoo! Groups Links
