Bob, et al Reply All bounced so there may be two postings of this repl;y
Since I had a dozen or so LM309Ks left over from a long ago production run, I replaced the board mounted regulator with the TO-3 chassis mounted 309K when I "upgraded" to the black box and completely eliminated worrying about dissipating heat from the regulator. Wiring from the 309 to the board was easy and neat and an in-line 3 pin Molex connector allows removal of the 'guts' to the lab bench & power supply for 'tweaking & tuning'. Phil, K3IB ----- Original Message ----- From: "Robert McGwier" <[EMAIL PROTECTED]> To: "Lyle Johnson" <[EMAIL PROTECTED]> Cc: <FlexRadio@flex-radio.biz>; "Jim Lux" <[EMAIL PROTECTED]> Sent: Friday, October 07, 2005 7:23 AM Subject: Re: [Flexradio] Eham Review > Ah. Thanks for clearing this up. Mine ALL had the linear regulator, > and we did in fact have to remove those and replace them with the > regulator on the other side of the board to mount to the heat sink. I > was wondering which of us had lost their minds. WHile it wasn't that, > I am clearly losing my memory! But the end analysis says, all of these > changes retrofit on the originial boards. > > Bob > > SDR-1000s were briefly produced with the switcher from the factory, as > > I recall. > > > > Later, some objected to the switcher RFI/noise and production > > SDR-1000s went back to linear regulators. > > > > Around that time the case appeared and made heatsinking it less of a > > problem. > > > > Enjoy! > > > > Lyle KK7P