Joel, I aggree the major is the equipment working. If it aint broke don't fix it.
Test gear measurments allow determining the source of a problem if there is a problem. If your ears say it aint working what is not working and in this case might not be the duplexer. Yes the test gear measurements do make a big difference. In a repeater there is so much that has to work. 73, ron, n9ee/r ps: with the start of this discussion has anyone said what type, model, etc of duplexer it is??? Might be a clue. >From: Joel <[EMAIL PROTECTED]> >Date: 2007/08/29 Wed PM 03:49:32 CDT >To: Repeater-Builder@yahoogroups.com >Subject: Re: [Repeater-Builder] Re: Duplexer input and output power > >Ok Skipp, and Jesse, So, I supposed that the specification of such, should be >presented by the manufacturers of the said, and with the said, right! Or >there is a general concept for duplexers, as in both examples, .1 to 3dB >Jesse, and Skipp input loss 15 to 35% And which will be more accurate to work >from dB or %. I always try to get a good balance when I'm tuning duplexers, >most times I ended up taking a loss on the power for a better result on the >receiver side, is this the best way to go? Or it depends on your situation, >whether or not the extra power would effect your weakest signal! (most times >a final touch up is done at the repeater site, it always make me feel like a >"perfectionist") Sometimes I still depend on my ears, then take a look at the >test gears, 99% of the time I go with my ears because the difference don't be >much when the duplexers are setup to the test gear figures. So, is the >figurers always the right thing to work with, or they are just guides for a >Tech with a bad hearing? v44kai.....Joel. ----- Original Message ----- >Fom: Jesse Lloyd To: Repeater-Builder@yahoogroups.com Sent: Wednesday, >August 29, 2007 12:54 PM Subject: Re: [Repeater-Builder] Re: Duplexer >input and output power >Ya, duplexers will have insertion loss. Typically you get more insertion >loss with more rejection, so its a balancing act. > >Insertion loss can range from .1 dB (very good) to 3 dB. > >Typically if I can get a duplexer to less than a dB I'm happy. > >Insertion loss (dB) = 10 log ( PIN / POUT ) > >So Pout = Pin x 10^(Insertion Loss/10) > >So for 50 Watts: > >.1 dB = 48.9 Watts >.3 = 46.7 >.5 = 44.6 >.8 = 41.6 >1 = 39.7 >1.2 = 37.9 >1.5 = 35.4 >2 = 31.5 >2.5 = 28.1 >3 = 25 > >Jesse > > > On 8/29/07, skipp025 <[EMAIL PROTECTED]> wrote: >Hi Joel, > >In the real world it depends on the duplexer type, size, quality, >operation and setup values, which may be fixed or adjustable. > >Just throwing out a generic rule of thumb... you will find many >duplexers lose about 15% to 35% of the input power. One would hope >for near zero loss but that will never happen. > >A common quality duplexer has adjustable probes or coax ports (the >name used is based on the duplexer type), which often trade what we >generic call insertion loss for increased performance. > >Loss through a duplexer is not always a linear graph of power in >vs power out. > >Just to put something out... be happy if a properly setup and >working duplexer delivers 75% to maybe 95% of the input power. >Be grateful if you receive better than 85% of the rated power. >A really "tight" duplexer might eat as much as 35% to 40% of >your input power and there are much worse possible examples. > >cheers, >s. > >> "Joel" <[EMAIL PROTECTED]> wrote: >> Is there a table or formula or ratio for power input to a duplexer, >> to the resulting output power of the said? For instance, if I put >> 10, 20, 50, 100 watts to the input, what should be the output, with >> a 50 Ohms at the load? >> >> example 10,20, 50, 100 watts in = x output @ 50 Ohms. "BASED >> ON A PROPERLY TUNED DUPLEXER" >> >> I think someone had a short for-instance on this, can't find it, >> and will like some insight on this. >> v44kai.....Joel. > > > > >No virus found in this incoming message. >Checked by AVG Free Edition. >Version: 7.5.484 / Virus Database: 269.12.10/977 - Release Date: 8/28/2007 >4:29 PM > Ron Wright, N9EE 727-376-6575 MICRO COMPUTER CONCEPTS Owner 146.64 repeater Tampa Bay, FL No tone, all are welcome.
