Paul N1BUG wrote: > Nate, > > Thanks for bringing that to my attention!
No problem, it's a head-scratcher. > That is weird. The info I have in the document came from a Decibel > Products catalog. We now have three freq ranges for the DB4076, all > from manufacturer documents. Hmmmmm. Since "official" info > conflicts, I guess all I can (or should?) do is add a note about the > situation and list the various frequency ranges we have. Heh. "Your mileage may vary." > I will add what specs that document provides on the 4075 while I'm > at it. I'll add a note about the Z and W suffix which I wasn't aware > of either. I'm getting the impression it's going to be like the "Linksys WRT-54GS", yeah, there's six models of that router now, or more, all with different hardware guts. Uggh. > Sounds like you had a fun project there! I haven't forgotten that I'd measure those cables, but have been busy and the duplexer's in use at the moment. I'll get it before the end of the week. Usually when it comes to projects like this, they ARE fun for me, but it's like drinking from the fire-hose. "I are just a dumb ham." My friend in this case, is an RF engineer with at least 20+ years in the industry, so I look at the instrument and say, "Wow that looks bad." and think to myself, "Wonder how you fix that?" He says with ease... "Ahh... this shows us that the length of the cables to the 'tee' are wrong. Here, let me grab about six random length cables that are shorter/longer than the ones installed and we'll figure out which direction it needs to go!" Five minutes later, the thing's doing factory spec on the desired frequency with a "perfect" pattern and a custom-made cable. At that point I'm usually dumbfounded... "Um, could you explain that... I mean, I think I get why that worked, but..." Then he dumbs it down for me... "Okay, if that's a pass cavity pair, and we're feeding it into a T, what does that make this cable and T? A transmission line... and what do transmission lines do?" Etc... etc. (Thank God I read the whole chapter on transmission line theory in the ARRL Antenna Book and barely understood all of it. @*#&@# Smith Charts!) And then I leave, go home, and think about it for a couple of months, and then one day the light-bulb goes on and I call him all excited... "HEY! I understand why that worked now!" And he laughs and tells me something else I didn't know... But in the meantime, he's shown me enough information to "experiment" on my own, which is what it's all about. Then I go find some crappy cans that we'd never use on a hill, and set them up on my IFR and start playing. It's just like little kids... you can hand 'em a ball and they'll throw it around, but it takes a bit more effort to teach them to play baseball! I hunted for two years to find that damn IFR at a "reasonable price" (yeah, test gear that costs more than I paid for my first car is "reasonable"? ha!) so I could go home and "play" after these sessions. Prior to that I was just frustrated... I'd learned something, but I knew I'd forget all about what I'd learned by the next time I was anywhere near a tracking-generator/spectrum analyzer combo (or service monitor). When "hobby" mixes with "professional experience"... it makes my brain hurt, because I get forced into learning something -- pros won't let you remain a dumb-ass for long. You eat up too much of their time. But yeah, it's "fun"... I guess. :-) I keep hearing all sorts of comments from pros who say things like, "I'd sure like to put this thing on the Vector Network Analyzer." Never seen anything done on one of those, but everyone you run into says they're the "only way to fly" when tuning something up. Someday I'll see one in action, hopefully. They seem to only reside in labs that are well-equipped and inaccessible to most normal folk. (Yeah, someone on here pointed out that older models sometimes do go cheap on FleaBay, but I'd get it home and stare at it stupidly wondering where to start with it. Haha. I'll stick with the IFR and proper loads on the ports on the cans... that get's me close enough for government work for the time being.) I still want to hunt down a nice 10 GHz disciplined clock source to feed the gear in the "basement lab" -- why? Because I can... well, if I find the right deal and it doesn't come right after the tax man. :-) Nate WY0X
