> One of the things we often fail to implement is the transmit bandwidth > being adjusted much like the receiving bandwidth on the other end. In a > contest situation likely the receiving station is using a 1500 to 1800 Hz > receiver bandwidth with likely band pass tuning such that the lower 300 to > 500 Hz of that is attenuated. This makes for an effective receive > bandwidth of some 1300 Hz or so. > > Now then with our transmitter setting for a "full width" normal SSB > bandwidth of say 2.6 or 2.8 KHz and a low end roll off of say 120 Hz this > make for an effective bandwidth of some 2600 Hz. Yes our transmitter > power is spread over that bandwidth. Wouldn't it make more sense to > concentrate the transmitter power over say 1300 Hz rather than 2600 Hz? > In doing so one gains almost 3 dB of effective power increase with > actually no increase in PEP. Plus the other folks on the band will > appreciate the narrow signals. > > Yes of course it will sound pinched up but in reality there is little > information in the male voice spoken range below 400 Hz and little above > 1500 to 1800 Hz. But hey, some of the compressed and processed signals > only serve to occupy the full 2600 Hz of bandwidth, with what? It's not > pretty for sure. So if you want a screaming DX pileup busting signal, > squeeze in the bandwidth and don't worry about the EQ or the special > purpose mike. Your good sounding SSB mike into that transmitter bandwidth > will do the job just fine and the neighbors on either side of your > frequency will appreciate your efforts. > > 73 > Bob, K4TAX > > > ----- Original Message ----- > From: "Lu Romero" <lrom...@ij.net> > To: <"Elecraft List <elecraft"@mailman.qth.net> > Sent: Tuesday, April 27, 2010 9:56 AM > Subject: Re: [Elecraft] W2IHY 8 band equalizer and EQ Plus > > >> Here Here! (or Hear Hear): >> >> Jim, are you a disciple of Frank Foti? :) >> >> I like Julius' gear, and I have worked with the EQPlus >> device at the NQ4I Multi Multi station on Rick's Orions. >> This box does make those radios sound quite good, especially >> with just a hint of "Delay" dialed in. >> >> I do find that the noise gate on the K3 has a "crackling" >> sound when muting and unmuting, making somewhat useless to >> me (if you pay attention to that nuance... I do. Otherwise, >> it works just fine) Lyle has done a great job with the TX >> chain on the K3... I would like to see some handles on >> Attack and Release as well as ratio, but then that could be >> painful to use if you dont know what youre doing. RF >> Clipper's attack and decay characteristics are rather >> generalised. >> >> The best way to fix audio ambient noise issues is through >> your environment's acoustics instead of "fixing it in the >> mix" with processing and gating. >> >> Folks shouldnt forget that we are transmitting into a very >> noisy medium. High dynamic range defeats intelligibility. >> SENSIBLE "compression" (RF Clipping) settings are your >> friends, as you then reduce the dynamic range (the >> difference between the loudest and the softest sounds in a >> given audio waveform) and have more "modulation density" to >> rise above the ambient noise on the band. >> >> Tailoring your frequency response to concentrate power in a >> given voice range will go a long way to making your signal >> "pop" out of the noise. Close talk the mic as much as >> possible and reduce the mic gain as Jim describes. >> >> A good example on how all these parameters work together to >> make your signal stand out can be gleaned by downloading >> VE3NEA's excellent "Voice Shaper" simulator program (its >> free). Use your favorite air mic and play with it for a >> while to get an understanding of how gates, >> compressor/limiters and EQ affect your signal in QRM and QRN >> conditions. >> >> Try to pay attention to the natural acoustics in your >> operating position, if you can. Curtains help, hard walls >> hurt. Carpet helps, Terrazo floors hurt. Try to set your >> operating position and/or microphone somewhat at an angle >> between hard reflecting walls to reduce phase cancelling or >> adding from the reflecting walls/surfaces. >> >> Personally, I am not a believer in ESSB. But different >> strokes for different folks, and I wont criticise folks who >> practice this "voodoo" until they become 8kHz wide and QRM >> me or I am able to understand them when listening to their >> SSB signal in AM mode (all that bass often creates a "pseudo >> carrier"). >> >> You would be surprised how well you can be heard using the >> built in features provided by Elecraft in the K3. It takes >> practice and a commitment to resist the temptation to "turn >> it up to eleven". >> >> -lu-W4LT- >> >> >> Date: Mon, 26 Apr 2010 10:57:04 -0700 >> From: "Jim Brown" <j...@audiosystemsgroup.com> >> Subject: Re: [Elecraft] W2IHY 8 band equalizer and EQ Plus >> To: "Elecraft List" <elecraft@mailman.qth.net> >> Message-ID: <20100426175705.d90c957...@gw1.nlenet.net> >> Content-Type: text/plain; charset="us-ascii" >> >> On Mon, 26 Apr 2010 16:18:01 +0000, Lance Collister wrote: >> >>> It very effectively cuts out the background blower noise >> >> Some of the major causes of audible background noise are 1) >> working too >> far from the mic; 2) running the mic gain too high; 3) using >> too much >> compression/processing; and 4) not rolling off the low >> frequencies. >> >> In a noisy environment, it always helps to work close to the >> mic. It is >> ALWAYS good practice to use the minimum mic gain needed to >> get good >> modulation, use no more than about 10dB of >> compression/processing, and >> roll off the low frequency content. It's good engineering >> practice for the >> highest quality broadcast stations, and it's good practice >> for ham radio. >> >> Indeed, the only difference between what's right for >> broadcasting and for >> ham radio is WHERE to cut the low end and HOW MUCH money to >> spend on >> compression/processing. Many years ago, I sold processing >> systems for >> broadcast stations that cost upwards of $10K in today's >> dollars, and I >> helped the chief engineers of those stations adjust them. I >> suspect that >> W8JI and K4TAX have similar experience. Before I spent ANY >> money on an >> outboard box for a ham rig, I would first follow all of >> those elements of >> good engineering practice. >> >> 73, >> >> Jim Brown K9YC >> >> >> >> ______________________________________________________________ >> Elecraft mailing list >> Home: http://mailman.qth.net/mailman/listinfo/elecraft >> Help: http://mailman.qth.net/mmfaq.htm >> Post: mailto:Elecraft@mailman.qth.net >> >> 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:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
