On my exec II receiver, the "casting" is just screwed together. Correct?
Chris Kb0wlf > -----Original Message----- > From: [email protected] [mailto:Repeater- > [email protected]] On Behalf Of Jeff DePolo > Sent: Friday, June 26, 2009 9:00 PM > To: [email protected] > Subject: RE: [Repeater-Builder] MastrII Receiver Failure > > > Chuck's got you going down the right path. At 51 MHz, you probably > only > have to take one turn off of each of the first two coils. At 52 MHz or > higher, you might have to take off two. You need a lot of heat to get > the > casting open (hint: a soldering gun, even a 300 watt Weller, ain't > gonna cut > it). Removing the coils/caps once you have the casting apart is pretty > straightfoward, as is removing one turn from each. It's not that bad > of a > job once you've done one or two, but the first one may cause you some > grief. > You should find that after the mods the receiver is plenty hot and > should > easily beat spec by a few dB. The LO/multiplier stages don't require > any > mods. > > If you want to cut corners, you might first see what your effective > sensitivity is at your repeater site on 6m. You may find that the > noise > floor is elevated substantially, and that getting the "bench" > sensitivity > down from 1 uV to 0.3 uV isn't going to make a damned bit of difference > in > the real world. > > --- Jeff > > > > -----Original Message----- > > From: [email protected] > > [mailto:[email protected]] On Behalf Of Chris Curtis > > Sent: Friday, June 26, 2009 4:16 PM > > To: [email protected] > > Subject: RE: [Repeater-Builder] MastrII Receiver Failure > > > > > > > > You are correct sir, no mesh. > > Isn't that that pits. > > > > So I take it I'll be removing some windings from the underside of > said > > trimmer caps? > > Or is there an easier route to sensitivity? > > =] > > > > Chris, > > Kb0wlf > > > > > -----Original Message----- > > > From: [email protected] > > <mailto:Repeater-Builder%40yahoogroups.com> [mailto:Repeater- > > > [email protected] <mailto:Builder%40yahoogroups.com> > > ] On Behalf Of Chuck Kelsey > > > Sent: Friday, June 26, 2009 12:09 PM > > > To: [email protected] > > <mailto:Repeater-Builder%40yahoogroups.com> > > > Subject: Re: [Repeater-Builder] MastrII Receiver Failure > > > > > > Do the two front end trimmer caps still have some "mesh" > > left, or are > > > they > > > at minimum capacitance? That may be your problem. > > > > > > Chuck > > > WB2EDV > > > > > > > > > > > > ----- Original Message ----- > > > From: "Chris Curtis" <[email protected] > > <mailto:demoman%40rollanet.org> > > > > To: <[email protected] > > <mailto:Repeater-Builder%40yahoogroups.com> > > > > Sent: Friday, June 26, 2009 10:45 AM > > > Subject: RE: [Repeater-Builder] MastrII Receiver Failure > > > > > > > > > I have a mastr EXEC II receiver (33 split) that I can't get > > sensitivity > > > to > > > increase. > > > > > > I replaced the fet as outlined below on the mastr II query. > > > No joy though. > > > > > > I'm using an am/fm-1200s to tune the receiver. > > > > > > .5~1uv is where the receiver is coming to life. > > > > > > I have a couple vhf and uhf exec II receivers that tuned up > > nicely in > > > the > > > .19~.2uv range so I "think" I'm doing/reading it correctly. > > > > > > Original freq was in the 46~49mHz range. > > > Current crystal (icom sent to and received from Bomar) on 51.75mHz. > > > > > > Any tips/hints/tricks to get a little more sensitivity? > > > > > > Thanks for the bandwidth! > > > > > > Chris > > > Kb0wlf > > > > > > > > > > > > > > > No virus found in this incoming message. > > Checked by AVG - www.avg.com > > Version: 8.5.339 / Virus Database: 270.12.85/2193 - Release > > Date: 06/26/09 05:53:00 > > > > > > > > > > ------------------------------------ > > > > Yahoo! Groups Links > > > > No virus found in this incoming message. > Checked by AVG - www.avg.com > Version: 8.5.375 / Virus Database: 270.12.83/2191 - Release Date: > 06/26/09 05:53:00
