Sartori was a consulting engineer at Texas Instruments when he wrote the article. In those days it was possible to have a semiconductor company manufacture custom devices on a small lot or sample basis. Therefore, he had access to a gold mine of resources few others had. However, custom devices were generally derived from an existing devices with some specifications differences. At some point in time, Sartori left TI and pursued other venues. I haven't looked at specific devices but it seem that with advances in component technology, it might be possible to improve or replace the original circuits. It would be a race against time however as the whole semiconductor industry is going to strictly surface mount devices in ever smaller packages. Thre could be even more opportunities as the package sizes change but the question is would an average Ham be able to handle it?
-------------- Original message -------------- From: "Jim Pruitt" <[EMAIL PROTECTED]> > > "Jim Pruitt" made an utterance to the drakelist gang > ---------------------------------------------------------------------- > Hello Neil. > > First, there was an article by SARTORI (the guy that later produced the > solid tubes commercially) in a 197x (1975 or 6 I think) QST article and was > written specifically for making solid state tubes for the Drake B and C > line. I looked very hard at it at the time. I had a friend that was an > executive for Tektronix. He pointed out to me that the specific transistors > were not that hard to find but that Sartori had spec'ed the hard to find > cases (TO220) for the transistors he used. I was recently told that Sartori > did that because he worked in the industry and got the transistor maker to > make them special for him so most people (including me) would have a hard > time finding them in the cases he recommended in the article. I recently > ran across a mod on some site (I thought it was WB4HFN but maybe not) where > the article took the 6EV7 vox tube (for the T4XB) (found it-- > http://www.geocities.com/maxmartin3/drake/tr4xc.html ) > which used simple 2N5485 and MPSA42 along with a string of 4 43v transcient > voltage suppressor diodes, a 12v zener and a 1N4007. My T4XB used to and > still eats that particular tube. > > The regulator tube for the T4 was even simpler but used a 150v (I think) > zener diode but those are getting hard to find now but they are out there. > > Anyway, there have been articles about making solid state replacements for > tubes. The one in QST that I mentioned above and I also remember an article > in Ham Radio Magazine that did the same thing but aimed at the R390 or KWM2 > (can not remember which but a Collins radio). Those transistors were even > harder (for me) to find. I think the article was in the early 80's. > > I purchased some blue LED builbs in #47 and #53 style holders from www. > superbrightleds.com ( http://www.superbrightleds.com/BA9S6_specs.htm ) in > their BA9 and BA7 models. The price was not bad. I think around $3 per > bulb but do not remember for sure. > > One of the individuals ( N9OO )on this list sells a blue LED light bar for > the TR7 at http://home.wi.rr.com/n9oo/products/tr7lamp/d7lamp.html . > > The filter material is not hard to get WA9TGT sells them ( > http://www.wa9tgt.com/Dial_Filter_Page.html ) and are quite cheap ($10 for 4 > sets) so if you do not have a local source these guys can sure help you out. > > I have not found a source for solid tubes or the parts to make them, at > least not on a reliable scale. > > Thank you. > > Jim Pruitt > > ----- Original Message ----- > From: "neil" > To: "DrakeList" > Sent: Sunday, November 26, 2006 1:45 PM > Subject: Re: [drakelist] WTB Solid tube solid state tubes for B and C line > > > > > > neil made an utterance to the drakelist gang > > ---------------------------------------------------------------------- > > Jim Pruitt wrote: > > > > > > "Jim Pruitt" made an utterance to the drakelist > gang > > > ---------------------------------------------------------------------- > > > I am again trying to find some solid tubes. I have seen none advertised > on > > > here for quite some time and wonder if anyone has any lying around that > they > > > would like to part with for the B or C line. > > > > Speaking of which... I've wondered how hard it would be to make some > > things like this (assuming, for discussion, that you could get some > > appropriate 7 or 9 pin bases to build on)? > > > > Diodes are obvious, and I suppose an FET could be rigged to work as a > > triode, but how would you replace a more complex (multi-grid) tube? > > Dual-gate mosfet or some combination of parts? > > > > Also - anyone tried using bright blue LEDs instead of bulbs + blue > > filters for the dial and meter illumination? My filters are shot... > > > > Neil > > KX2Y > > ---------------------------------------------------------------------- > Submissions: [email protected] > Unsubscribe: [EMAIL PROTECTED] - unsubscribe drakelist in body > Hopelessly Lost: [EMAIL PROTECTED] - help in body of message > Zerobeat Web Page: www.zerobeat.net - sponsored by www.tlchost.net > ----------------------------------------------------------------------
