Gareth describes a very creative application with frequency agile receivers scanning various commercial repeater inputs.
In the ham world we've applied scanning repeater receivers to our six-meter repeaters, which allow us to comply with the current 600KHz and original 500KHz "legacy" repeater offset. We also scan the 52.525 simplex channel for activity... One six-meter repeater receiver scans both input offsets and stops on the active frequency. Since the application uses a Midland Mobile as the six-meter repeater receiver we also use a priority look-back scan function to ensure the formal repeater frequency input always captures the repeater. In the case of the 600KHz & 500Khz repeater inputs there is no additional duplexer hardware required. Both frequencies "sneak through" the same pre-selector/duplexer filters without any modifications. The use of Scanning Receivers can be very creative... but also quickly get out of hand if you're easily excited. cheers, s. > "Gareth Bennett" <[EMAIL PROTECTED]> wrote: > > We have used a similar, and unique way of linking multiple sites here in NZ, > > Utilising four sites and multiple CTCSS, We utilise One repeater per site, Vertex Standard VXR-9000, programmed to scan all four frequencies (That site repeater input frequency, and the other three repeater sites output (TX) frequencies. > > Once valid activity has been detected, TX is on the single allocated frequency for that site location. > > The VXR-9000 has a tone panel integral to the repeater, so can decode/encode 16 CTCSS or DCS codes. > > Needless to say frequency co-ordination is very important, as each repeater site is also listening on the output frequencies as well. To make this work for our client, separate TX and RX antennas were required, as well as some clever filter engineering. > > What I am saying is that a repeater that has multiple channels, and that can also scan, can replace your link receiver in some instances. > > All the best for 08' > > Cheers > _________________________________________________________________ > > Gareth Bennett > > > This email is confidential, if you received this message in error, or you > are not the intended recipient, > please return it to the sender and destroy any copies. > Thank you. > > > ----- Original Message ----- > From: Kerincom > To: Repeater-Builder@yahoogroups.com > Sent: Saturday, January 05, 2008 5:04 PM > Subject: Re: [Repeater-Builder] Linking two shared repeaters > > > Each of my repeaters operate on different frequencies .e.g. Repeater #1 rx 483.9mhz and TX on 489.1mhz 5.2 meg split. > #2 may be on rx 490mhz and TX on 495.2mhz > Correction my #2 repeater link receiver is tuned to #1 output frequency (489.1mhz) .and transmitt on the #1 input frequency (483.9mhz). > Yes each on my clients on the private have a separate ctcss frequency assigned to their radios for TX and rx so they can only hear their own cars. > > > Thank You, > Ian Wells, > Kerinvale Comaudio, > 361 Camboon Road.Biloela.4715 > www.kerinvalecomaudio.com.au > > -------Original Message------- > > From: Jim Brown > Date: 5/01/2008 12:36:06 PM > To: Repeater-Builder@yahoogroups.com > Subject: Re: [Repeater-Builder] Linking two shared repeaters > > I think I understand what you are saying Ian. Your > #2 repeater has it's input frequency on the #1 > repeater's output frequency. That way you would only > require one extra receiver (on a third frequency) and > precedence circuit at the #1 repeater site. The #2 > site would have to have it's output on the third > frequency to make it all work. > > I think you have simplified the system down to the > minimum required hardware to make it work. CTCSS > Transmitted only while an input is present would round > out the system requirement. Your multi-user CTCSS > controllers should keep things private as different > users use the different tones. > > Sometimes thinking outside the box can make for a real > worthwhile reduction in hardware. > > 73- Jim W5ZIT > > --- Kerincom <[EMAIL PROTECTED]> wrote: > > > Hi again Jim > > With your thinking below .My remote private site > > should work in the same > > sort of way as what you are suggesting except while > > s2 has a signal on it > > it sends this signal to both s2 users and back to s1 > > repeater at the same > > time.In return the signal works the same as your > > first 3-5 lines below.I > > only require one link radio on the remote sites and > > not one at each end of > > the link .However with our open we have a separate > > link repeater paired with > > the s1 (explained better in my response to skip) so > > the link system works at > > the same time as the central site repeater.In the > > open system we don't link > > the TX frequencies directly from site to site > > .I.e.(s1tx to s2rx)(s2tx to > > s1rx) due to a error in frequency allocation,which > > will be fixed and which > > we expect to link directly with our private system > > as we wont get the sites > > frequencies licensed so close together next time > > > > Thank You, > > Ian Wells, > > Kerinvale Comaudio, > > 361 Camboon Road.Biloela.4715 > > www.kerinvalecomaudio.com.au > > > > -------Original Message------- > > > > From: Jim Brown > > Date: 4/01/2008 8:25:48 AM > > To: Repeater-Builder@yahoogroups.com > > Subject: Re: [Repeater-Builder] Linking two shared > > repeaters > > > > Ian, here is my thinking. When site 1 has a signal > > on > > the repeater input, the signal from site 2 is > > blocked > > because of the circuit that gives precedence to the > > local site repeater receiver. When a site 1 user > > unkeys, there will be no CTCSS tone coming back from > > site 2 to key the site 1 repeater. The combination > > of > > the precedence circuit and CTCSS requirement for > > both > > repeaters keeps the system from locking up. The same > > circuit would be required between the receivers at > > site 2 as in site 1. And both repeaters would have > > to > > be configured to only transmit a CTCSS tone when a > > user keys the input, not during the squelch tail. > > > > 73 - Jim W5ZIT > > > > --- Kerincom <[EMAIL PROTECTED]> wrote: > > > > > I will have a look at the circuit and see .The > > > problem we found with link > > > setup 1 upper design is we could not have one link > > > radio on one site and one > > > on another site as when the site 2 link stops > > > transmitting and rx site 1 > > > tail retrips site 2 and keeps them on .Another > > > problem was while s1 link in > > > transmitting s2 receiver is trying to pick up the > > > incoming signal and s1 > > > link transmission at the same time . > > __________________________________________________________ > Never miss a thing. Make Yahoo your home page. > http://www.yahoo.com/r/hs >
