Any reasons? Thanks, Michael H. Cox michaelh...@gmail.com
-----Original Message----- From: "JOHN MACKEY" <jmac...@usa.net> Date: Sun, 03 Jan 2010 21:55:33 To: <Repeater-Builder@yahoogroups.com> Subject: Re: [Repeater-Builder] Mastr II mods and parts I would not recommend that duplexer for a repeater. ------ Original Message ------ Received: Sun, 03 Jan 2010 08:47:16 PM PST From: Michael Cox <michaelh...@gmail.com> To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Mastr II mods and parts > 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 >
