Duane and all, If you plan on converting a Mastr II to 220, realize that there is a Segment of frequencies that WILL NOT WORK full duplex in the same radio set. This is a VERY similar situation to the UHF Mastr II's.
On a UHF Mastr II it is a well known and documented fact that there are certain frequencies that will not duplex in the same radio chassis. This had been a mystery for some time. The resolve had always been to simply order the crystals "opposite side injection". That was the remedy and no one quite knew why it was the way it was, but that was the fix that worked. Well, one day that Kevin and I had nothing better to do. (Yea, Right!!!) We ran in to a similar problem on a 220 Mastr II conversion. This proceeded to turn into a lengthy 2 day research project into why this self-quieting phenomenon happens. This has been documented and will be written into an article once there is again a time where there is nothing better to do in the repeater-builder shop. Moral of the story: There is a band of frequencies from approximately xxx to xxx that is not useable in the 220 band. Unlike the UHF Mastr II, the 220 problem cannot be fixed by simply flipping the injection side of the receiver. (This leads to a whole new set of problems and calculations.) Again, all of this info will be made available for public dissection when time allows. Scott ----- Original Message ----- From: "Duane Brantley" <[EMAIL PROTECTED]> To: <[email protected]> Sent: Wednesday, April 27, 2005 1:17 PM Subject: [Repeater-Builder] Lookling to build a 220MHz repeater > > > Hello everyone, > > I recently purchased 4-cavity duplexer for a 220MHZ repeater. I'm > thinking about using a GE Mastr II mabile radio for the Rx/Tx part. > I'm very green at this and figuring this out on my own. Do I need 2 > Mastr II radios, or will one work? I will modify it for 220 service > once I know how many I need to get. Also, is the NHRC-3/M2+ a good > comtroller for $189? Or is there a better one. This will be a low > power repeater . Looking to run 30-50 watts. > > Thanks for the help, > > Duane > KD5NFQ > > > > > > > > > Yahoo! Groups Links > > > > > > > Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
