I have tuned three of the Mitrek VHF units to 144.890 mhz following the instructions in the service manual and they all worked just fine with no modifications. 73 Jim wd0ekr
----- Original Message ----- From: Kevin Custer<mailto:[email protected]> To: [email protected]<mailto:[email protected]> Sent: Thursday, December 18, 2008 9:02 PM Subject: Re: [Repeater-Builder] Holiday Special - MICOR 2 meter receiver conversion from W3KKC Tom, You say you find similar operation on 4 or 5 units. By that do you mean they won't make book specification on any frequency below 146 MHz? If that is the case, I would believe something is wrong. I have seen many Mitrek high-band receivers that were tuned for 144 something and had very good sensitivity. Let me ask you this.... When tuned at 144.89, is the front-end tuning all "one ended", or is there adjustment to spare? In other words, can you tune the front-end without the fear of the tuning screws falling into the casting? If you have room left to go lower in frequency, then the front-end is not the problem, and you'll need to look elsewhere for the lack of sensitivity. Another question - do these 4 or 5 units tune and make book spec sensitivity on their original high-band channel? I guess what I'm saying is I doubt the problem is the front-end helical resonators, but if there is a need for a conversion I'm not opposed to looking into making a modification available, if it is needed. If there are others on the list that have had good luck with the Mitrek on frequencies below 146 MHz, please chime in and let us know what you have and how well it works. Kevin Hello Kevin You are correct on your freqs for xmit and rcv. The Mitrek units I have will only tune receive to 146.00Mhz. This leaves more than one meg to go to meet tolerance on 144.890. I have tried 4 or 5 units and find similar operation of all. This is the reason for my question about the Micor coils working for Mitrek. Thanks. 73 de Tom Manning, AF4UG ----- Original Message ----- From: Kevin Custer<mailto:[email protected]> To: [email protected]<mailto:[email protected]> Sent: Tuesday, December 16, 2008 8:44 PM Subject: Re: [Repeater-Builder] Holiday Special - MICOR 2 meter receiver conversion from W3KKC Tom, Do you mean 144.89 MHz? I would think your repeater would *transmit* on 145.490 MHz.... At any rate, no conversion is necessary for the Mitrek to make book specification sensitivity on 144.890 MHz. Kevin Good afternoon Kevin My need is to convert two or more Mitrek receivers to cover 145.49Mhzz, which is our receive freq for our repeater. Thanks. 73 de Tom Manning, AF4UG ----- Original Message ----- From: Kevin Custer<mailto:[email protected]> To: [email protected]<mailto:[email protected]> Sent: Tuesday, December 16, 2008 12:19 PM Subject: Re: [Repeater-Builder] Holiday Special - MICOR 2 meter receiver conversion from W3KKC Tom Manning wrote: Good morning Kevin I have a question. Will these coils also work in a Mitrek? Thanks. 73 de Tom Manning, AF4UG Hi Tom, To answer your question, the conversion will not work in the Mitrek. Unlike the MICOR, the Mitrek high-band unit that is most common has a lower tuning limit of 146.00 MHz as specified from the factory. This means that the units normally tune anywhere in the 2M ham band without modification. What frequency do you need to listen on? Kevin
