Randy, I've experienced problems similar to what you describe on several MII and found it to be harmonic noise on the ptt (osc 10v) line. Installing a >10 uh inductor where the line enters the exciter pcb did wonders for mine. You may also want to install a pair of inductors on the 12v lines in the PA (at the feed through caps). The original GE design has this on a number of their PAs.
While, once I did have a spur that required me to move the entire mobile radio away from another mobile cased unit, I've never had a desense problem internally between the tx and rx in a mobile. NO6B may want to revisit his problem MII and look at the ptt line. He may be pleasantly surprised. -Steve ----- Original Message ----- From: wb8art To: Repeater-Builder@yahoogroups.com Sent: Thursday, December 13, 2007 4:44 AM Subject: [Repeater-Builder] Re: MastrII Mobil repeater spur Thanks Bob & Paul for the response. Yes it is the unit with the compensation line running between all ICOMS. This is kind of where I have been leaning to.. Course the consternation is that its been working for a long time without an issue or at least one on that freq. It may have just moved to a location to be noticed. I will purse it some more and Bob I suspect you maybe ahead of us on this. I have a station I am working on to replace the mobiles so may not worry about this to long. Question while on the topic. How do you guys generally connect the controller to a station? Do you get the Molex connectors and pins or what exactly? If so, you have a easy source on and nos. for the pins and plugs? Thanks Randy --- In Repeater-Builder@yahoogroups.com, "Paul Plack" <[EMAIL PROTECTED]> wrote: > > Randy, > > I'm trying to recall...is this a rig where one ICOM has the temperature compensation network, and develops a control voltage which is then distributed and shared by all the other ICOMs in the radio? If so, and the problem just showed up one day, perhaps there's some RF bypass cap or other component that's failed within the ICOM itself, allowing RF to travel that DC temperature control line. > > It's been 10 years since my last MII mobile conversion, so the memories are somewhat dusty, but I'd try another ICOM to see. > > 73, > Paul, AE4KR > > ----- Original Message ----- > From: wb8art > To: Repeater-Builder@yahoogroups.com > Sent: Wednesday, December 12, 2007 6:06 AM > Subject: [Repeater-Builder] MastrII Mobil repeater spur > > > One for the wonderfull experts here. I have been working to many > nights this week to be able to think straight. > > Our MastrII converted mobil developed a spur problem last nite. Were > on 145.43 and the spur was on 145.11. Very strong and subbing in a > standy unit produced the same results. The only components used in > both are the ICOMs and the stock tone card (used to encode tone > only). The fix was to pull the reciever ICOM (144.83)killing the > local rx. Guys what are your thoughts on this and the possible fix. > > Randy > Yahoo! Groups Links
