That highly-modified Motorola MICOR amp would definitely fill in some of those dead spots in a repeater's coverage area! However, most of us would never be able to get a Repeater coordinated through our local coordination councils for that kind of output power. Mine is coordinated for 250 Watts, but a pair of 8877's probably couldn't be throttled back to that kind of "QRP" power. ALPHA 77SX HF amplifiers use a pair of 8877's, and they will do 5000+ watts output no problem. But a pair of 8877's are VERY expensive!
I have plenty of new, spare 8560A tubes, which is what the original VHF MICOR 250-Watt PA deck uses. I wonder if that KL7FB amp conversion article would give the plate line change info so that the original 8560 tubes could be used on 2-Meters? If anyone finds a link to the original article, please post it. I was able to find a web page with pictures of this KL7FB Motorola amplifier 8877's conversion, which makes reference to the original article, wherever it was published: http://home.cogeco.ca/~ve3kh/amplifiers.html Unfortunately, so far I've not been able to find the original article that he mentions. Thanks, LJ -----Original Message----- >From: kl7fz <[EMAIL PROTECTED]> >Sent: Feb 26, 2006 9:16 AM >To: [email protected] >Subject: [Repeater-Builder] Re: Micor 375 Watt TLD5082 question? > >There were several guys who did major conversions of these amps for >use in the ham band and at much higher power for use with EME. All >based on the initial work done by KL7FB, Chris. >Not for the faint-hearted though. The thing was basically gutted and >a new set of sockets and tubes installed (2 x 8877). Plate line was >modified, and the changes were noted and documented by several of the >the users. > To run the thing up to see what it would do at full power, special >terminations and power supplies were brought in. Somewhere around 6KW >out was noted. But normal use of the amp was on much smaller and in >some cases, portable power supplies that would yield full legal >power. Not much strain on the amp at that level and those expensive >tubes will last forever. > Last I heard there were six or seven of the things in use. > There was quite a bit of documentation on the web at one time. >Should still be out there. > Look for KL7FB or dual 8877 EME amp. > > This conversion would definately take care of the weak spots in your >repeater coverage! All you would need would be several remote >receiver sites to balance it out. ;) > > KL7FZ > > > > > > > > > > > > >--- In [email protected], Bryon Jeffers K0BSJ ><[EMAIL PROTECTED]> wrote: >> >> I have a Micor 375 Watt station that has the TLD5082 high power PA. >I have >> a fresh set of tubes in the station and on a commercial frequency >(156.???) >> it makes good power, about 400 watts or so.. I have tried to get it >to tune >> up on a 147.??? ham frequency but to no avail. I have heard of >these going >> down with no problem but this one just won't do it. I of course >checked MOL >> to see if the needed parts were available to convert it to the ham >band >> (TLD5081) but they are NLA... >> >> Has anyone converted one of these to the ham band and if so what >parts did >> you change? >> >> According to the manual the grid tuning cap and some other assorted >coils >> are needed, but I would like to hear from someone that has made one >of >> these work in the ham band... >> >> Thanks for your time! >> >> Bryon K0BSJ >> > > > > > > > > > > > >Yahoo! Groups Links > > > > > > > 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/
