[1000mp] Inrad CW Mod Install

[John Tait]

Subject: Re: [1000mp] Inrad CW Mod Install

Very useful and succinct.
    Another one for Tech\Yaesu\1000MP\    {:o)
Thanks Ian... 
      John EI7BA



> It really isn't that bad - just lay off the full-strength morning 
> coffee!
> 
> If this is an older MP, here are a few things to make it easier...
> 
> 1. Build the little network of R1-R2-C1-C2 first. This network is very 
> simple if you use miniature components on a scrap of perf-board, which 
> can be stuck to the chassis beside the IF board (double-sided foam 
> "Sticky Fixers").
> 
> If you don't have the miniature components, you have to find some more 
> difficult and complicated way to mount them - so buy the parts that will 
> let you do it the easy way:
> 
> R1 470k or 500k mini trimpot.
> R2 10k mini trimpot
> C1-C3  0.1uF miniature ceramic disk or multilayer, 0.1in lead spacing.
> 
> Do not include C3 on the board - see below.
> 
> 2. Unscrew the fan from the PA unit, and lay them down separately on the 
> bench next to the transceiver. You don't have to un-plug all the wires 
> in order to do this. I can't remember exactly what you do need to 
> un-plug, but it wasn't much.
> 
> If you're not confident about being able to put everything back together 
> again, make notes or take digital photographs of where everything was, 
> at each step. (Roger's right about giving yourself enough time, because 
> re-assembly is easier to remember if you do it all in one session.)
> 
> 3. Don't bother with the green wire from the RF board - that was only 
> needed because Tom wanted to experiment with values for C3, and he found 
> that 0.1uF was uncritical.
> 
> The rest of us can simply find the existing C1216 using Tom's 
> photographs, bridge it with a 0.1uF cap, and then put the RF board back.
> 
> Make absolutely sure it really is C1216! There is only *one* component 
> that *exactly* fits Tom's description and photographs. Double-check 
> after you have soldered in C3.
> 
> 4. The RC network will need a ground wire, so while the IF board is 
> upside-down to solder a wire to C2148, also solder a ground wire to the 
> edge of the board. Replace the IF board, connect the two wires to the RC 
> network, and then stick the perf-board down to the chassis.
> 
> 5. When tweaking R1 and R2 for minimum clicks, use SLOW keying so you 
> can hear the separate clicks on make and break. Aim for the best balance 
> between the two.
> 
> 
> As I said, these hints are for the older MP. I'm not sure exactly how 
> they play for the 1000D or the MkFives, but hope there might be 
> something helpful for those models too.
> 
> 
> -- 
> 73 from Ian G3SEK