I associate them with A, B, and C batteries under the desk...
On Thu, Feb 17, 2011 at 6:27 PM, Michael Tondee <[email protected]>wrote: > I usually associate AM operation with the classic radio buffs or "boat > anchor" collectors. Obviously, judging by this thread, not everyone who > operates AM fits this category but I have to wonder what some of these guys > think when they hear one of the "newfangled Flex SDR's" on AM! > Michael > > On 2/17/2011 5:44 PM, Kevin Feeney wrote: > >> On 2/17/2011 4:46 PM, Michael Tondee wrote: >> >>> I was going to say, same reason people still use CW hi hi...but I must >>> admit CW is a lot more reliable from of QRP level communication than AM is. >>> Anyone tried a 1500 on AM yet?? >>> 73, >>> Michael, W4HIJ >>> >> >> I've heard a couple on AM, and they sound fine. And while AM is not as >> good for QRP as cw (or JT65!) it does do surprisingly well. For the last few >> weeks there's been an AM QRP net running in the northeast on Sunday >> afternoons and doing quite well. It was started off by some folks getting >> interested in the Retro75 kits, but has expanded to all kinds of tube and >> solid state rigs at this point including some throttled down flex units. >> >> AM doesn't suffer quite as bad as the numbers make it out to since they >> usually compare only one sideband. But in practice, with a proper receiver >> you receive both sidebands and combine their energy back into the recovered >> audio and get the advantage of spectral diversity in case one sideband is >> taking hits. There is still a lot of power going into the carrier with no >> intelligence, but OTOH, it does tend to quiet the frequency between words. >> >> As far as SSB with a pilot carrier sounding as good, I remain to be >> convinced. I think it depends on how you generate the SSB. Mechanical or >> crystal filters seem to do something to the audio in the passband, probably >> relating to the phase shifts needed to get the steep roll offs at the edges, >> that seems to affect how the audio sounds - and I'm no audiophile. Of course >> there are phase shifts in the receiver filter as well, and some folks prize >> the R390 and Drake receiver because of their LC IF filters over the 390A >> with the mechanical filters and the later Drakes with crystal filters >> because of their sound. People who use phasing exciters seem to have nice >> audio, and whatever 'magic' is used to generate AM in the Flex does a very >> nice job also. >> >> When I built large HF systems with Harris RF Communications in the 70's we >> had 1kw and 10kw transmitters that were capable of SSB, 4 ISB, full carrier >> AM, and pilot carrier (-26db) AM for use with the RF550 receivers with >> synchronous detectors. They sounded good, but not as good as a nice plate >> modulated AM signal, or a Flex. >> >> No matter what equipment you use, AM is fun. One thing I especially like >> about it is that it puts me in contact with folks who have often followed a >> similar path through ham radio - starting off in the era of AM and tubes, >> and with people who very often build and modify their own equipment and who >> really know what's going on inside of the box. It's a nice community. Plus >> it just plain sounds good. There's a time and place for punchy, 'space >> shuttle' audio with minimal bandwidth, but when I just want to hang out and >> chat with friends, I find it fatiguing and eventually annoying. I much >> prefer AM or FM for relaxed casual conversation. >> >> I purchased my Flex 5000 specifically with AM operation in mind. I like >> all modes, but good AM performance was on my requirements list and the Flex >> 5000 does a pretty good job at delivering. >> >> 73 de Kevin, WB2EMS >> >> >> >> > > _______________________________________________ > Flexedge mailing list > [email protected] > http://mail.flex-radio.biz/mailman/listinfo/flexedge_flex-radio.biz > This is the FlexRadio Systems e-mail Reflector called FlexEdge. It is used > for posting topics related to SDR software development and experimentalist > who are using beta versions of the software. > _______________________________________________ Flexedge mailing list [email protected] http://mail.flex-radio.biz/mailman/listinfo/flexedge_flex-radio.biz This is the FlexRadio Systems e-mail Reflector called FlexEdge. It is used for posting topics related to SDR software development and experimentalist who are using beta versions of the software.
