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 > -----Original Message----- > From: [email protected] [mailto:Repeater- > [email protected]] On Behalf Of DCFluX > Sent: Saturday, June 20, 2009 4:13 PM > To: [email protected] > Subject: Re: [Repeater-Builder] MastrII Receiver Failure > > Buy a couple of spares and keep them in the manual at the site. > > On Sat, Jun 20, 2009 at 1:48 PM, Adam Feuer<[email protected]> > wrote: > > Wow! Thanks for the tip. I changed out that FET and the sensitivity > is > > back to normal. I went to Radio Shack and used an MPF-102. > > > > Now the question: Do I put it back at the site with the Radio Shack > > device? (I'm not sure who makes their transistors) Or do I order > > something better? > > > > Thanks again! > > > > Adam N2ACF > > > > > > DCFluX wrote: > >> Replace the FET that is in the helical casting. on the RF Pre- > selector > >> board. It is a 2N4416, Radioshack carries the MPF-102 as a readily > >> available substitution. I'd use a J-310 if you have one. > >> > >> See: > >> http://www.repeater-builder.com/ge/lbi-library/lbi-4991g.pdf > >> > >> On Fri, Jun 19, 2009 at 11:27 AM, Adam Feuer<[email protected]> > wrote: > >> > >>> Hello All > >>> > >>> I've had a MastrII low band receiver (29.540) on the air for close > to 10 > >>> years now with no issues. It's been very sensitive and breaks > squelch at > >>> around .17uv. > >>> > >>> Recently, after a lightening storm, the receiver went deaf. I went > to > >>> the site thinking that the antenna might have got struck by > lightening > >>> but it turns out that the receiver now breaks squelch and around > 8uv. > >>> (or whatever is in between the 5 and 10uv setting on my IFR1200S) > The > >>> antenna checks out fine. > >>> > >>> Having only tuned these receivers up and never having to trouble > shoot a > >>> failure, I'm wondering if anyone knows of a "smoking gun" when it > comes > >>> to a MastrII receiver failure like this. I'm going to dig out the > book > >>> and see what I can find but any help or guidance would be greatly > >>> appreciated. > >>> > >>> Thanks in advance! > >>> > >>> Adam N2ACF > >>> > >>> > >>> ------------------------------------ > >>> > >>> > >>> > >>> Yahoo! Groups Links > >>> > >>> > >>> > >>> > >>> > >> > >> > >> ------------------------------------ > >> > >> > >> > >> Yahoo! Groups Links > >> > >> > >> > >> > >> > > > > > > > > ------------------------------------ > > > > > > > > Yahoo! Groups Links > > > > > > > > > > > ------------------------------------ > > > > Yahoo! Groups Links > > > > No virus found in this incoming message. > Checked by AVG - www.avg.com > Version: 8.5.339 / Virus Database: 270.12.73/2180 - Release Date: > 06/20/09 06:15:00
