[Today,\u00a0 no running]<\/p>\n
I have been reading up on duplexers in support of my recent acquisition of a large set of band-pass VHF filters.\u00a0 At one time\u00a0 in the past I was interested in building a 2-meter repeater.\u00a0 But I have kind of left that idea behind.\u00a0 There are already a lot of repeaters available to me and most of them go unused.<\/p>\n
But, now that I have some cavity filters I would at least like to play with them a bit.\u00a0 Unfortunately I don’t have a signal generator in the 100-180 Mhz range.\u00a0 All I have is CW\/AM down to 144 Mhz and FM up to 148 Mhz.\u00a0 I guess I could work with that a bit and see if I can find the passband on one of these filters.\u00a0 It would be comforting to know they will work in the right frequency range after all.<\/p>\n
The www.repeater-builder.com website is a great resource for anyone interested in building a repeater.\u00a0 And there is a Yahoo group for aspiring repeater builders.<\/p>\n
I still don’t think I am interested in building a repeater.<\/p>\n
For anyone who doesn’t know, a repeater is a radio receiver and transmitter that work at the same time.\u00a0 Stuff coming in on the receiver is piped out through the transmitter.\u00a0 It is common to have both the receiver and the transmitter share the same antenna.\u00a0 Since the receiver is listening for faint signals and the transmitter is generating a loud signal on the same antenna, the repeater has to have a mechanism to keep the signals separate.\u00a0 First the transmitter and receiver don’t operate on the same frequency.\u00a0 Second, a filtering system is used to keep unwanted signals from going into the wrong places.\u00a0 High Q cavity filters are used so that the two signals can be relatively close together.\u00a0 And the filtering system is called a duplexer.\u00a0 On the 2-meter amateur band the traditional frequency separation is 600 kHz.<\/p>\n
The purpose of a repeater is to extend the range of small systems.\u00a0 Generally you put the repeater at a high, prominent point where it can hear signals from small hand-held transmitters.\u00a0 And the repeater transmitter likewise covers the range back to the hand-held units.\u00a0 Instead of having then a walkie-talkie range of a mile or two you can get extended range of the elevation and higher transmit power.\u00a0 But the users still just use walkie-talkie sized equipment.<\/p>\n
<\/p>\n","protected":false},"excerpt":{"rendered":"
[Today,\u00a0 no running] I have been reading up on duplexers in support of my recent acquisition of a large set of band-pass VHF filters.\u00a0 At one time\u00a0 in the past I was interested in building a 2-meter repeater.\u00a0 But I have kind of left that idea behind.\u00a0 There are already a lot of repeaters available […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5,6],"tags":[],"class_list":["post-625","post","type-post","status-publish","format-standard","hentry","category-ham-radio","category-operating"],"_links":{"self":[{"href":"http:\/\/w0ep.us\/OM\/index.php?rest_route=\/wp\/v2\/posts\/625","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/w0ep.us\/OM\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/w0ep.us\/OM\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/w0ep.us\/OM\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/w0ep.us\/OM\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=625"}],"version-history":[{"count":4,"href":"http:\/\/w0ep.us\/OM\/index.php?rest_route=\/wp\/v2\/posts\/625\/revisions"}],"predecessor-version":[{"id":629,"href":"http:\/\/w0ep.us\/OM\/index.php?rest_route=\/wp\/v2\/posts\/625\/revisions\/629"}],"wp:attachment":[{"href":"http:\/\/w0ep.us\/OM\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=625"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/w0ep.us\/OM\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=625"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/w0ep.us\/OM\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=625"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}