When I opened the 10GHz transverter diecast box I found some rainwater had indeed entered the box. Part of this was due to the fact I had not fully tightened down the four lid screws and part due to the fact that I hadn't applied sealer to the lid/box seam.
With the water removed, the box dried out and the dessicant bags replaced I set about upping the transmit power. I had suspected that the DB6NT transverter tx gain pot had been turned way down to accommodate my usual 2W of 144Mhz drive. With the pot readjusted I was easily able to get 10W output as indicated on the remote meter in the shack. This using 100mW on 144MHz in the shack.
After scraping the old sealant off the box seams I replaced the lid, screwing the four holding screws down tight. Then I used a mastic gun to squeeze Down Corning 745 non-corrosive sealant along all the box seams.
A quick test and up went the mast again.
All appears well, but with 6m open to North America, it didn't have any on air tests as I preferred to call a VO. Unfortunately It seems the opening was not reaching thisart of the East Anglian coast as all I hear was the one VO and I couldn't make myself heard to him!
So I went away to do some measurements on a commercial 2m preamp ready for a published review in Radcom........