[Repeater-Builder] Re: Rebuilding a Stationmaster
--- In Repeater-Builder@yahoogroups.com, "Chris Curtis" wrote: > > I found this online: > > http://www.srgclub.org/CollinearAnt-Repair-SMaster.html > > probably not what the original poster was looking for though. That was precisely what I was looking for! Thanks!! > > Chris > Kb0wlf > > > -Original Message- > > From: Repeater-Builder@yahoogroups.com [mailto:Repeater- > > buil...@yahoogroups.com] On Behalf Of n3ssl > > Sent: Thursday, September 10, 2009 12:34 PM > > To: Repeater-Builder@yahoogroups.com > > Subject: [Repeater-Builder] Re: Rebuilding a Stationmaster > > > > Hi Group, > > I think the guy is talking about the new station master made by celwave > > RFS. No, mine is definitely not new. :) About all I can ID on it is the "Phelps Dodge" label. They were bought by Celwave/RFS I hear, but this one predates that. rj
[Repeater-Builder] Rebuilding a Stationmaster
Hi all, The repeater-builder website mentions rebuilding a Stationmaster that has developed noise by taking it apart and resoldering the sections. I have a Stationmaster that has developed that noise so I brought it down the hill. The replacement antenna cured the noise, but it's not the same class of antenna so my coverage area is not what it was nor will that antenna survive the winter. Now comes the project of actually rebuilding the broken antenna. Upon starting to take it apart though, a big question came up. Are there Stationmaster models that can and models that can't be rebuilt? I don't have the model designator of mine. The antenna predates my association with the site (in the context of maintaining it anyway) and the label is largely faded away. I can read "Phelps Dodge" and "Super Stationmaster" but that's about it for the label. The antenna is for 2 meters and is 21 feet, 6.75 inches long from the bottom of the metal base to the top of the metal topcap. The thing that worries me as far as being able to take it apart is that there seems to be something like epoxy between the radome and the metal base. There's a black substance at the junction of the radome to the base and upon taking the three screws out of the side of the metal base I can see the layer of metal, the layer of the black stuff, the layer of the radome and then the inner metal that the screw goes into. Can someone who's taken these apart tell me if that black substance is indeed bonding the parts together and I'm stuck looking for a new antenna, or with all the screws out and just a little more force will it indeed come apart? Thanks for any pointers and 73 rj kb6ytd
[Repeater-Builder] Re: wp-639 rexolite
--- In Repeater-Builder@yahoogroups.com, Gary Hoff wrote: > > I have in face tuned a WP-639 and would guess for that freq swing from > 146.97 to 146.88 it will be very little movement of the rod assuming the > pass tuning is correct. Remember, the rexolite rod is tuning the notch > and that > notch is relative to the pass setting of the invar rod. It is extremely > sharp and > has to be moved only very slightly to find the deepest part of the > notch. Thank you! That is exactly the info I was looking for. Looking at the charts on the spec sheets I suspected it would be relatively sharp and a small amount of movement. I hadn't found the sharp notch yet so before I spent a lot of time looking for something that wasn't there I wanted to ask someone who had been there. So now I know I need to go hunting and do so quite carefully. Again, thank you! [...] I would tune it for you for nothing but I have > no Idea where you are located and I'm sure there are others who would also if > you would give a location so someone could respond. Thanks for the offer but I don't get to Idaho often. :) I'm in the far North of California, West of Redding. rj - kb6ytd > Gary - K7NEY > > hbbcara wrote: > > > > Hi again, > > > > In my first post I miswrote a thing or two and much confusion as to my > > question ensued. Hopefully I've written this more clearly. Thank you > > to all who responded to my earlier question and my apologies for > > wasting your time by having you answer the wrong question. > > > > I have a wp-639. I'm its at least third owner and don't know its > > previous history. It's got a factory sticker marked 146.97 / 37. I > > don't know anyone who currently has the correct equipment locally and > > I don't have the budget to take it to a radio shop so I've used > > alternate methods of tuning similar to mentioned on the repeater > > builder website. I've gotten it tuned to work OK with my repeater on > > 146.88 / 28 but I'm guessing it could be better. > > > > In tuning the pass adjustments, there was a definite "sweet spot." Go > > a quarter or a third of a turn off of that and there was a definite > > difference. But I didn't find that "sweet spot" in tuning the reject > > and I wonder how wide of an adjustment it usually is. What I mean is, > > for example the pass tuning went from "not very good" to "good" to > > "not as good" within about one turn of the knob. In tuning the reject, > > should I be looking for that pattern while moving the rexolite over an > > inch of travel, a half-inch, two inches or ? > > > > So my question is not how to tune it but as I tune it, how much should > > I expect to have to move the rexolite rods to notice the "not good > > good not good" pattern? Or will it even be there? > > > > I suppose the question is only to those who have tuned a wp-639 for a > > standard 600kc split. Someone who hasn't tuned a `639 will be basing > > their answer on a comparison to something they have tuned, which may > > not be all that comparable. > > > > For the sake of brevity I won't post the method I used to tune it > > unless someone wants to know it. > > > > Again, thanks to those who answered earlier and thanks in advance any > > who answer this. > > > > rj > > > > >
[Repeater-Builder] wp-639 rexolite
Hi again, In my first post I miswrote a thing or two and much confusion as to my question ensued. Hopefully I've written this more clearly. Thank you to all who responded to my earlier question and my apologies for wasting your time by having you answer the wrong question. I have a wp-639. I'm its at least third owner and don't know its previous history. It's got a factory sticker marked 146.97 / 37. I don't know anyone who currently has the correct equipment locally and I don't have the budget to take it to a radio shop so I've used alternate methods of tuning similar to mentioned on the repeater builder website. I've gotten it tuned to work OK with my repeater on 146.88 / 28 but I'm guessing it could be better. In tuning the pass adjustments, there was a definite "sweet spot." Go a quarter or a third of a turn off of that and there was a definite difference. But I didn't find that "sweet spot" in tuning the reject and I wonder how wide of an adjustment it usually is. What I mean is, for example the pass tuning went from "not very good" to "good" to "not as good" within about one turn of the knob. In tuning the reject, should I be looking for that pattern while moving the rexolite over an inch of travel, a half-inch, two inches or ? So my question is not how to tune it but as I tune it, how much should I expect to have to move the rexolite rods to notice the "not good good not good" pattern? Or will it even be there? I suppose the question is only to those who have tuned a wp-639 for a standard 600kc split. Someone who hasn't tuned a `639 will be basing their answer on a comparison to something they have tuned, which may not be all that comparable. For the sake of brevity I won't post the method I used to tune it unless someone wants to know it. Again, thanks to those who answered earlier and thanks in advance any who answer this. rj
[Repeater-Builder] Re: wp-639 -- How far should I expect to move the invar rods?
--- In Repeater-Builder@yahoogroups.com, "Eric Lemmon" wrote: > > You don't move the Invar rods at all- those are the pass adjustments. [...] Just so we're talking apples and apples, the Invar rod is > in the center of the cavity, and it usually has a black knob on it. OK, so much for re-reading my post so I didn't write something embarrassing! I was calling an apple and orange. The question remains though, how much should I expect to have to move the plastic stick in the reject adjustment? And should I expect to hear a definite center? The duplexer came to me at least 3rd hand. I guess part of what (and why) I'm asking is, does it sound like the notch adjustment is working correctly? [...] > Since you have eliminated the original tuning with experimentation, > perhaps it would be a good idea to properly tune the duplexer with the appropriate test equipment. That would certainly be the best idea, but there are two problems. 1) The only guy I know in the area who had such equipment had his shop broken into recently and among other items taken were his spectrum analyzer and tracking generator. 2) It still doesn't answer the question of how far I should expect to move the adjustment. Using the right equipment would give a nice graphical display of what the adjustment was doing but I still wouldn't know if it was a matter of I was looking for the null in the wrong place or the adjuster wasn't working. > The tuning info is here: > Been there, read that. :) (And many other articles about duplexer tuning linked on the site. - thanks for your contributions, by the way) > 73, Eric Lemmon WB6FLY 73, and thanks for the quick reply, even though my nomenclature misnomer was embarrassing. :) rj > > -Original Message- > From: Repeater-Builder@yahoogroups.com > [mailto:repeater-buil...@yahoogroups.com] On Behalf Of hbbcara > Sent: Saturday, July 18, 2009 5:48 PM > To: Repeater-Builder@yahoogroups.com > Subject: [Repeater-Builder] wp-639 -- How far should I expect to move the > invar rods? > > > Hi all, > > In tuning the reject for a wp-639, how far should I expect to move the > invar rods to find the notch? > > In tuning mine (the poor man's way - system on the air receiving a weak > station) I didn't find a definite place I"d call a null. There was more > noise on the signal with the rod pushed most of the way in and less > noise with the rod most of the way out, but it was a gradual change. I > expected to find it noisy with the rod mostly in, noisy with the rod > mostly out and at some point in between a quieter spot. > > SO my question is, should I hear a definite "noisy-quiet-noisy" > pattern as I move the rods and if so, over how much motion of the rods > is it likely to fall? An inch? Half-inch? Three inches? Or would that > pattern only be noticeable with "the right equipment." > > (Some background - the duplexer is from an uncertain origin, but it has > a factory sticker saying 146.97 - 146.37 with the ports marked "high > input" and "low input." I'm using it on 146.88/28 so it shouldn't be an > "upside-down" issue.) > > Thanks for any info! > > rj >
[Repeater-Builder] wp-639 -- How far should I expect to move the invar rods?
Hi all, In tuning the reject for a wp-639, how far should I expect to move the invar rods to find the notch? In tuning mine (the poor man's way - system on the air receiving a weak station) I didn't find a definite place I"d call a null. There was more noise on the signal with the rod pushed most of the way in and less noise with the rod most of the way out, but it was a gradual change. I expected to find it noisy with the rod mostly in, noisy with the rod mostly out and at some point in between a quieter spot. SO my question is, should I hear a definite "noisey-quiet-noisey" pattern as I move the rods and if so, over how much motion of the rods is it likely to fall? An inch? Half-inch? Three inches? Or would that pattern only be noticeable with "the right equipment." (Some background - the duplexer is from an uncertain origin, but it has a factory sticker saying 146.97 - 146.37 with the ports marked "high input" and "low input." I'm using it on 146.88/28 so it shouldn't be an "upside-down" issue.) Thanks for any info! rj
