Randy, I was thinking high VHF before, but the same precautions apply to low VHF. It happens that the interconnect boards are the same for low and high bands. I have a 6881013E60 service manual in front of me now. You should get a copy of this vital book, along with the 6881025E60 controls manual, before you go any further with this conversion. By the way, please advise the complete model number of your station. It should be something like "C71RCB-3106D" and may be on a narrow metal tag riveted to the top rear of the cabinet, or glued to the unified chassis. It's important for the readers of this list to know what you have, in order to suggest a course of action.
All of my experience with MICOR equipment has been with high band VHF base and repeater stations, and I will defer to others who have converted low band VHF stations to 6 meters. You should visit the MICOR modification pages on this site to learn valuable tips about 6m conversions. I would expect that both the PA and the harmonic filter would need some work for operation on the 6m band. The fact that your station was operating at 48.520 MHz is nice, since it must therefore be in the highest of the four band splits, and probably the easiest to convert to 6m. Yes, the transmitter interconnect board is also different for repeaters. Your base station probably has a TLN5893 board, which lacks the necessary filtering for full duplex service. The repeater station uses the TLN5894 board, which includes filtering components on each interface line. The base station board also has some circuitry for the antenna network that is not present on the repeater version. The good news is that the backplane board is the same for both stations. However, you should have the shield covers for both receiver and transmitter shelves, and all front module covers should be in place. The two shield covers are used on repeater stations only, and provide extra insurance against stray RF from the exciter shelf causing problems on the receiver shelf. Please don't be tempted to operate your repeater without all the shields and filtering elements in place; the MICOR is an excellent machine when it is properly configured, and taking shortcuts in this area will surely impair its operation and may interfere with other radio systems. 73, Eric Lemmon WB6FLY randyallenk wrote: > > Thanks Eric for your info. > I can see me now trying to get desense out of RX, thank you. I have the > 5648apr RX interface in it just like you thought. I have an old unit for > parts. It has 5646a1 in it. Can I swap them out? The old unit is nasty. But > if better to use that chassis, I could clean it real good. They both have a > 5644a back plane and I didn't check the xmit interface board for a number . > Is it different too? Any other ideas? can I mod it with some feed throughs or > ??? how about I buy one off somebody ready to rock? Will the 5646a1 I got > work ok? The interface boards look the same but I haven't seen both sides of > them. Any other goodies or tricks I should know about? I plan on using > external control and know of the mods for that, and I think I might have to > mod the receiver caps. It's a 50 MHz unit and I'm putting it on the ham > band. It was factory tuned to 48.520 that's close to 52, but all the reading > I've done says cap change, never even thought about the rx interface board. > Than ks for any help in advance > randy AG4ZQ > > > > > > Yahoo! Groups Links > > To visit your group on the web, go to: > http://groups.yahoo.com/group/Repeater-Builder/ > > To unsubscribe from this group, send an email to: > [EMAIL PROTECTED] > > Your use of Yahoo! Groups is subject to: > http://docs.yahoo.com/info/terms/ Yahoo! Groups Links To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ To unsubscribe from this group, send an email to: [EMAIL PROTECTED] Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
