Will this Duplexer work with the Mastr II repeater? http://cgi.ebay.com/UHF-50W-6-CAVITY-DUPLEXER-FOR-REPEATER-FREE-TUNING_W0QQitemZ350300447727QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item518f88a3ef
On Sun, Jan 3, 2010 at 9:32 AM, WA3GIN <wa3...@comcast.net> wrote: > > > For fun we operated a 400 watt erp repeater with two antennas and no > duplexer. We were able to achieve about 100db attenuation by using the roof > equipment penthouse. The transmit antenna was mounted on the top of the > penthouse and the receive antenna was installed diagonally from the transmit > antenna on the roof below the penthouse. Each antenna was physically > separated by the penthouse structure. Transmit performance was good and > receiver performance was good about 270 degrees minus the abstructed zone. > No feedback or other issues. Eventually, we installed TXRX 6 can duplexer > and utilized the penthouse antenna. Receive coverage regained 360 degree > coverage. So, it is doable if you have the right antenna site. > > Best, > dave > wa3gin > > > ----- Original Message ----- > *From:* Kevin Custer <kug...@kuggie.com> > *To:* Repeater-Builder@yahoogroups.com > *Sent:* Sunday, January 03, 2010 11:12 AM > *Subject:* Re: [Repeater-Builder] Mastr II mods and parts > > > > Michael Cox wrote: > > Thank you for your help. I appreciate it! I've put a couple of questions > inline below. > > Well - you'll need a duplexer no mater the price... <grin> >> > > I was under the impression that if I had two antennas, I could get by > without a duplexer. Thanks for the heads up. > > > While two antennas will work, and you'd initially think there is a cost > savings using two antennas, that isn't always the case. > > The determining factor usually ends up being the length and size of > feed-line necessary to get from the repeater to the antenna. On UHF, unless > the feed-line length is really short, you'll want to use some type of > hard-line cable. The cost of this cable, depending on type and length, can > be costly. It may be less costly to use one antenna and a duplexer then to > install two antennas and have two runs of feed-line. In addition, you'll > usually end up with a better balanced system using one antenna because using > two can cause a disparity if both antennas don't have the exact same pattern > - which could be difficult to achieve depending on the tower space > available. In installations where you have to pay rent on tower space - > it's usually by far cheaper to purchase a duplexer. > > RE: Power Amplifier > > Are these what I'm looking for? > > > Generically - Yes. > > It looks like there is a UHF and a VHF version of the PA. Is that > correct? > > > Yes. > > Are they not compatible with each other? > > > No. > > VHF and UHF are two totally different bands. You cannot use a UHF PA on a > VHF repeater and vice-versa. The third one you listed is a Mobile PA - not > something you'll want. > > You want a UHF Station PA like the second one you listed - but it isn't the > exact one either. The one you want requires 200 mW of drive - not 20 watts > - but, the correct one looks very similar to the one in your number two > listing. > > I don't presently see a good candidate on eBay - but they show up all the > time. > > Duplexer - used WACOM Products WP-678 (or similar), also available from >> eBay. >> > > I couldn't find any on eBay. Any guesses what I'd be paying for something > like this? > > > $250 plus shipping. > > > > >> Controller - I recommend a NHRC model that plugs into the "Systems" >> board, or, one of the Pion & Simon models that plug into the card cage. >> >> http://www.nhrc.net/ge-stuff.php >> http://www.pionsimon.com/products.htm >> > > > It looks like I can use the NHRC-4/M2 to make it a linked repeater. If I > go with the Ham repeater, I'll most likely do that. That would require, if > I understand correctly, another radio connected in, so that will have to be > done later with future funds. :) > > > Correct. > > > If I decide to make it a GMRS repeater, I won't have to worry about that > and will go with the PSE508-2, as its a little less expensive. > > > Also a good choice. > > Kevin > > > > -- ----------------------------------------------- Michael H. Cox michaelh...@gmail.com
