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Author Topic: Repeater antenna as passive repeater?  (Read 2439 times)

SOFAR

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RE: Repeater antenna as passive repeater?
« Reply #15 on: May 23, 2019, 04:54:46 PM »

'how can I tell which three members of eHam not to ignore myself...'


Huh?
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KX4QP

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RE: Repeater antenna as passive repeater?
« Reply #16 on: May 24, 2019, 06:50:27 PM »

I figure there must be three (maybe more) members of this forum who are willing to talk to someone without calling them a troll when they try to answer the question they were asked.

Else, I'd be interested in how I get tagged as a troll for trying to answer the question.  This was a somewhat useful thread with some technical information being passed in non-technical language.  Then suddenly someone called me a troll.  It's a little confusing...
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K7RJB

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RE: Repeater antenna as passive repeater?
« Reply #17 on: June 01, 2019, 01:31:34 PM »

It's even more irritating that you feel the need to respond to questionable posts.
Get some thicker skin.

If you can't bounce a signal around the mountain you need to try EME, IRLP, Allstar, Echolink or some other method to get into the remote system.

None of these solutions are free, easy, or discovered without some experimenting.

Weak signal work on a hand held is frustrating at best.
A 4 element beam will give a nice boost and concentrate power where it is most effective for your purposes.
4 pieces of welding rod and a broom handle will get you started.
Get up as high as you can, wave that thing around and bounce some signals.
Use good Coax.

If you can't hear it, you are unlikely to hit it even if you lobbed a nuke at it.

I am able to hit multiple repeaters over 75 miles away with just a Comet GP6 and ~40w.
It's really frustrating when I can hear a station but they can't hear me, and I know it's not my antenna.

A good antenna with a small radio, is better than a big radio with a crappy antenna.
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K0UA

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RE: Repeater antenna as passive repeater?
« Reply #18 on: June 01, 2019, 06:29:42 PM »

Passive repeater is two yagi's back to back with coax (minimal) in the middle.  One yagi pointed at the repeater, one yagi pointed downhill at your house, short good quality coax in the middle.  This is much like the mine scenario outlined by another poster or the yagi upstairs pointed at repeater and the 1/4 wave magnet mount in the basement.  You don't have a lot of signal to work with, BUT. If you go up on the ridge and take your HT and hook it to a yagi, and you can work the repeater with ease, THEN and ONLY then can you consider the passive repeater idea. Which still may not work, but would be worth a shot. Of course IF a yagi on a pole back at your house would work, which we still don't know if it would or would not work that would be simpler to make and maintain, then two antennas up on the ridge.  It is just an idea which CAN work, but no guarantee it will work after you have put in all that effort.
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73  James K0UA

KX4QP

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RE: Repeater antenna as passive repeater?
« Reply #19 on: June 02, 2019, 04:46:23 AM »

I haven't been able to schedule a half day to drive up to the ridge and try raising the repeater in question direct, though I have a four-day weekend coming up (4th through 7th of July).  I should be able to get in from up there; I routinely key repeaters at similar distances with this radio without major terrain blockage (there's one on a TV tower that I can get into from forty-plus miles, if I'm on a hilltop, and the ones on the ridge are reachable from thirty miles or more if there isn't a hill in the way).  I'm not sure how much difference it will make being on 440 band; all the ones I use regularly are in 2m, but with good line of sight it shouldn't matter.

As noted, I haven't heard the repeater in question from home, but I don't spend hours listening to the HT at home (should probably try that soon).  If I get a bounce with a Yagi, it would seem I might be able to hear things I can't hear with the Nagoya 771 that's on the HT now, since the Yagi's gain applies on receive as well as transmit.  I need to get a piece of coax that fits the HT connector before I can experiment with a Yagi on that radio, however.  I may see if I can get one from someone in my club at the next meeting (next weekend) or at Field Day (three weeks).  If not, there's time to order in a piece from Amazon or GigaParts.
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KX4QP

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RE: Repeater antenna as passive repeater?
« Reply #20 on: July 04, 2019, 06:36:36 PM »

Today (with the day off from work for the holiday) I managed to get out with my HT and find where I can and can't reach the Fancy Gap repeater that networks with my club's weekly net (KF4OVA on 442.425, + offset, PL 107.2).  I spent about an hour driving around little back roads, turning around for end of road and avoiding private roads, looking for locations where I could key the repeater from my HT and where Google Maps terrain view seemed to indicate I might be able to also "see" my home.  The long term goal is seeking a location where I might be able to put up a passive repeater and reach "around" Sauratown Mountain to that repeater (the ones actually on Sauratown Mountain don't have the required connectivity).

Looks like there are two real possibilities.  First, the eastern end of Sauratown Mountain itself, and the saddle between it and Hanging Rock.  I had clean reception of the repeater's carrier where NC 66 passes through the saddle, and a good bit up the Sauratown Mountain side of on Taylor Road (go too far up on Sauratown Mountain Road and the interference from the 10-12 radio towers on the high part of the ridge gets too deep -- and most of the mountain is roadless, posted land).  The other possibility, less likely to be practical, is a ridge actually inside Hanging Rock State Park.

I did see what I took to be a ham antenna on a house near the intersection of Hwy 66 and Taylor Road -- it was a vertical with four ground plane rods, seemed to be sized for 10m or 6m (though possibly a CB base station antenna -- don't know how popular CB still is in north central North Carolina).  That location has good access to the Fancy Gap repeater, and I'm pretty sure I can reach it from home (unfortunately, I don't have the gear to set up a temporary echo unit at home to check that side of this access puzzle).  I wonder if there's a way to turn an address into a call sign, the way QRZ or the FCC database will turn a call sign into an address?
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K5LXP

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RE: Repeater antenna as passive repeater?
« Reply #21 on: July 06, 2019, 06:16:33 AM »

So what would be the plan for these two locations?  A remote base or link of some kind?

Mark K5LXP
Albuquerque, NM
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KX4QP

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RE: Repeater antenna as passive repeater?
« Reply #22 on: July 06, 2019, 04:40:10 PM »

So what would be the plan for these two locations?  A remote base or link of some kind?

Mark K5LXP
Albuquerque, NM

The plan was to start by putting a passive repeater up there somewhere (two Yagis, aimed appropriately, with a very short piece of feed line between), and mount a third Yagi at home, connected to my 8W HT (at least for a start).  If that didn't work, I had a nebulous idea for a solar charged two-HT improvised repeater (can be done for about $300-$400 including the solar panel and upgrade antennas for the HTs).

That plan became moot, at least for the near future, because, as I found out the day after my test expedition, the club net I've been trying to reach for the past four months has been semi-permanently moved to a single, non-networked repeater local to the club's center community (Thomasville, NC).  I'll need to start the testing over; this newly chosen repeater is almost exactly the opposite direction, and is much lower (20-50 feet AGL, AFAIK).  My passive would have to be on the inaccessible side of Sauratown Mountain, or on the near side of Hanging Rock (also inaccessible, and within the state park, if I could even reach that from home).  No more thousand feet of rock between me and the repeater, but still a couple hilly areas a couple hundred feet above sight line.
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K5LXP

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RE: Repeater antenna as passive repeater?
« Reply #23 on: July 08, 2019, 03:59:15 PM »


Looks like the jury is out awaiting a new survey.  I'd pretty much dismiss the idea of a passive repeater.  Microwatts aren't going to be enough to make the haul.  Something I'd be looking at is either finding another ham in the coverage area you've got line of sight to, or entertain the idea of linking up via internet connection to them, e.g. echolink and set up a remote base.

Mark K5LXP
Albuquerque, NM
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KX4QP

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RE: Repeater antenna as passive repeater?
« Reply #24 on: July 08, 2019, 04:31:49 PM »


Looks like the jury is out awaiting a new survey.  I'd pretty much dismiss the idea of a passive repeater.  Microwatts aren't going to be enough to make the haul.  Something I'd be looking at is either finding another ham in the coverage area you've got line of sight to, or entertain the idea of linking up via internet connection to them, e.g. echolink and set up a remote base.

Mark K5LXP
Albuquerque, NM


There was an Echolink-enabled repeater on the Piedmont Repeater System they're no longer using (they may get back to that one when the club's own repeater is back in operation after moving the equipment).  Unfortunately, it was off the air for at least several months (i.e. since before I got my license) before the club net was moved to the current repeater.  Almost every other member of the club is in range of the repeater they're now using.  I'm the odd man out because I chose a slightly more distant club that meets at a time I can attend, due to lack of a club (that I've been able to find) that's actually reasonably local to me, and the nearest club meets on weeknights, after my bedtime (getting home from a club meeting at 10:30 PM before a 4:00 AM alarm is asking for trouble on the next day's commute).

I suppose another option I could pursue is to bring a motion at a club meeting to change the night for the club's net, but I still don't want to have to drive a half hour or more home from a location where I can hear and key the repeater, well after dark.
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