Would the "Boots" need type acceptance if offered by Elecraft? Does the 15 dB gain maximum rule apply? Are QRP amplifier kits legal in any case? Maybe Elecraft could offer a 1watt beacon kit based on the XG3. There seems to be a lot of interest in QRP beacons.
73, Rick Dettinger K7MW On Jun 25, 2011, at 3:14 AM, John Ragle wrote: > A few days back I inquired of the list if anyone knew of a small > post-amp that would prefilter the XG3 square wave and give it about 30 > dB boost. There were no answers. The problem seems to be that most QRP > or QRPp amps already require a few tenths of a watt input, and the 1 > mW > from the XG3 is just too tiny... > > I have been specifically thinking about using the XG3 (in its spare > time) as a 6 meter beacon. Just hooking it up to a "resonant" > antenna is > not (IMHO) legal, since antennas (think center-fed half wave doublets) > do not discriminate against ODD harmonics. FCC requires better...see > ยง97.307 Emission standards, section (e). > > I have been thinking this over, and it looks like the best answer is > to > build around a 20 dB gain block running in to a power module, such as > the MAR-6 gain block into a M57735 power module. The output from the > XG3 > would need to be low-passed before the gain block, since the usual > gain > blocks are quite wide band (e.g. DC-3 GHz, etc.). > > HOWEVER, a glance at the manual for the XV series transverters already > shows a transmit path designed and ready, in the schematic for the > XV50. > Aside from ~dozen SMD caps in the filtering (not needed!) connecting > the > mixer to the SGA7489 gain block, the needed component list is rather > short, about 26 parts, most of which are mundane. I asked Wayne if > Elecraft would bag up these parts and sell them to me as a partial > kit, > and his response was more or less positive, but he requested that I > poll > the list to see if there is any other interest: > > -----> A partial kit, no enclosure or circuit board, to assemble a 6 > meter post-amp for the XG3 that would produce 1-5 watts. <----- > > Note: the SGA7489 gain block is obsolete but the device remains in the > supply chain. > Note: the RA30H0608M power module is designed to put out 30 watts in > the > 68-88 MHz range. To drive it to this power level from the XG3 might > require cascading two gain blocks. A substitute part is the M57735 > mentioned above, designed for 25 watts at 50-54 MHz. > > I think that a post amp built "ugly style" around these ideas would > fit > into an Altoids tin. The only hitch is proper heat-sinking of the > power > module. The layout used for the XV50 takes care of the biasing. > > ***** > > So, I am asking the list: "Is there any interest out there amongst XG3 > owners in having Elecraft bag up a partial kit as outlined above?" > > ***** > > This note is also going directly to Eric at Elecraft, who holds the > reins for manufacturing... > > John Ragle -- W1ZI > > P.S. The schematics for the XV50 is included in my manuals for my > XV144, > which BTW works wonderfully... > > > > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[email protected] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
