Dan, Jim is right on the money. According to my excel spreadsheet, 443T075/448.075 thru 444T/449.075 are bad when high side injection is not used.
This question comes up periodically: "Why does my receiver self-quiet when I key the transmitter?" It just so happens that there is a harmonic of the transmitter that falls very close to a sensitive spot of the receiver. The range above is +/- 10Hz at the harmonic(s) in question. There is allot of math involved and many pages of expiation are needed for an adequate explanation. The solution is easy however; order your rx crystal for high side injection. Scott Scott Zimmerman Amateur Radio Call N3XCC 612 Barnett Rd Boswell, PA 15531 ----- Original Message ----- From: <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Friday, April 13, 2007 8:25 AM Subject: Re: [Repeater-Builder] Mastr II mobile in repeater service Noise in receiver > Did you order a receive crystal on the high side injection for the new > frequency? The GE receivers can do some strange things with a low side > injection crystal in the 443.xx range. > > 73 - Jim W5ZIT > > -----Original Message----- > From: [EMAIL PROTECTED] > To: [EMAIL PROTECTED] > Sent: Wed, 11 Apr 2007 2:51 PM > Subject: [Repeater-Builder] Mastr II mobile in repeater service Noise > in receiver > > Ok all you helpful folks. I need some ideas. > I have a UHF mastr II tuned to the ham band. I am using a NHRC-3/M2 > controller. I have a 2 meter remote base on the 2nd port of the > controller. I have both audio delay boards installed. I am running a > TS-64 ctcss board in full encode/decode. My output is 25watts out of > the cavities. I am using a set of TX/RX Varinotch cans. I am running > a ARR preamp. > The problem I have is this. Sometimes on the receive signal it > sounds "crunchy". A signal will be full quieting and then it will > get "crunchy" and then slowly clear up. On weaker signals > the "crunchy sounding audio will just stay that way. I thought maybe > this was caused by the AD but it was still there when i removed the > delay board. > This system was on 444.450/449.450 for abt 7 years with no problems. > I moved and had to change the frequencies to 448.450/443.450. I also > had a IFAS board fail a few months ago and swapped it out with one I > had from another UHF Mastr II. > Thoughts? ideas? places to start? Bring it on!! I need to make this > thing work rght or take it off the air. > > Dan > ________________________________________________________________________ > Check Out the new free AIM(R) Mail -- 2 GB of storage and > industry-leading spam and email virus protection. > > > > > > Yahoo! Groups Links > > > > > > -- > No virus found in this incoming message. > Checked by AVG Free Edition. > Version: 7.5.446 / Virus Database: 269.4.0/759 - Release Date: 4/12/2007 > 7:58 PM > >
