Re: question for psk users
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There was a question posted about power level and IMD when
transmitting PSK31. I recent built a pskmeter kit and checked out my signal. I found that the 5-bar rule of thumb for the K3 is good for up to about 70 watts. IMD remains below -27db. Above 70 watts drive must be reduced. But you shouldn't ever use that kind of power on psk, anyway. I drive my amp with 25 watts, so I just leave it there and run psk barefoot. That's plenty of power. Glen W6GJB ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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On May 1, 2012, at 9:23 AM, GLEN BROWN wrote: > Above 70 watts... But you shouldn't ever use that kind of power on > psk, anyway. I'm curious why you think this. 73 de Eric, KG6MZS ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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In reply to this post by Glen, W6GJB
Eric KG6MZS asked why wouldn't you run more than 70w on PSK
Because with the close spacing of signals in the various PSK sub-bands, a signal of more than about 50watts will completely annihilate all the other PSK signals and make that sub-band unusable for everyone else. The rule of thumb for being polite on PSK is to operate 25-30w max. I won't claim that there aren't some who are operating more (you Cuban stations know who you are), but many/most of us will avoid QSOs with people who are obviously running 50w+ 73s Jon, WB2RYV ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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I'm very ignorant on the subject, having made exactly one PSK QSO in my life. But wouldn't
propagation, antennas, etc. all have a bearing on signal strength at a given location? Dipole vs. beam makes a greater difference than 25 vs 50 watts. On 5/1/2012 8:46 PM, Jon Perelstein wrote: > Eric KG6MZS asked why wouldn't you run more than 70w on PSK > > Because with the close spacing of signals in the various PSK sub-bands, a > signal of more than about 50watts will completely annihilate all the other > PSK signals and make that sub-band unusable for everyone else. The rule of > thumb for being polite on PSK is to operate 25-30w max. I won't claim that > there aren't some who are operating more (you Cuban stations know who you > are), but many/most of us will avoid QSOs with people who are obviously > running 50w+ > > 73s > Jon, WB2RYV -- Vic, K2VCO Fresno CA http://www.qsl.net/k2vco/ ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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In reply to this post by Jon Perelstein
On 5/1/2012 8:46 PM, Jon Perelstein wrote:
> Because with the close spacing of signals in the various PSK sub-bands, a > signal of more than about 50watts will completely annihilate all the other > PSK signals and make that sub-band unusable for everyone else. This is urban myth that keeps getting propagated and eventually everyone believes it as gospel. It's only basis in fact is that folks using el-cheapo radios can find it difficult to separate small signals from big ones. That's nothing new -- it's been true as long as radio has existed, and it's why it's worth spending money on better receivers. It's why I dumped my S38D in 1957 for a BC348, and why I was thrilled when an OT loaded me an SX101 a year later. It's why I bought an Omni A in 1980, an Omni V in 2003, then a K2, then an MP and finally a K3 a few years ago. And it's a big part of why the serious DXpeditions all use K3s. There are MANY factors that contribute to signal strength, including antenna efficiency and gain, antenna pattern, propagation, and yes, transmit power. Of those factors, transmit power is the SMALLEST. The difference between 50W and 500W is 10 dB. The difference between a short indoor random wire with no counterpoise and a resonant outdoor dipole will often be 15-20 dB. A 3-el Yagi is typically good for another 5-6 dB, add 3 more dB for making it twice as long. What is FAR, FAR more important to prevent interference is making sure that your signal is CLEAN -- no sidebands produced by audio distortion, or by distortion in a poorly adjusted rig or power amp. 73, Jim K9YC ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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Jim Brown wrote:
>> Because with the close spacing of signals in the various PSK sub-bands, a >> signal of more than about 50watts will completely annihilate all the other >> PSK signals and make that sub-band unusable for everyone else. > >This is urban myth that keeps getting propagated and eventually >everyone believes it as gospel. [...] The reason why a strong signal will "annihilate all the other PSK signals" is that most users are trying to receive an entire 2.5kHz bandwidth in one gulp. This means that even one strong signal within that bandwidth will activate the AGC and drive all the other signals down. Regrettably most PSK users don't understand what is happening, so they have to rationalize it into simpler terms like "It's a crime to be loud." >There are MANY factors that contribute to signal strength, including >antenna efficiency and gain, antenna pattern, propagation, and yes, >transmit power. Of those factors, transmit power is the SMALLEST. And propagation is by far the BIGGEST factor in making someone's signal loud, for the most innocent of reasons. >What is FAR, FAR more important to prevent interference is making sure >that your signal is CLEAN -- no sidebands produced by audio distortion, >or by distortion in a poorly adjusted rig or power amp. IMD is certainly another important factor. Naturally, IMD will show far more clearly on a strong signal than a weak one so once again this gets rationalized into "strong = IMD". But PSK's big, unacknowledged 'elephant in the room' will always be the habit of receiving in a 2.5kHz bandwidth. Unfortunately this is deeply engrained in the PSK culture. -- 73 from Ian GM3SEK http://www.ifwtech.co.uk/g3sek ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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They like being able to watch all 20 conversations in the bandwidth at the
same time, and see new signals pop up without having to be tuning around. Move the pointer and click on the new signal to answer. The 2.5 is a "mini-band" by consensus. The audio out in reality is an IF. So there are rules to keep things nice in the 2.5. One of them is to run little enough power so you don't push down other signals in the passband by hitting RX AGC's, AND so you don't add power to the inevitable IMD products in one's own TX. Power for PSK does seem to be such a waste, after watching a signal decode perfectly that I could not hear in the passband noise with my ears. PSK is kind of like living in an apartment building with thin walls. For decorum and peace, need to keep the levels down. 73, Guy. On Wed, May 2, 2012 at 4:05 AM, Ian White GM3SEK <[hidden email]>wrote: > But PSK's big, unacknowledged 'elephant in the room' will always be the > habit of receiving in a 2.5kHz bandwidth. Unfortunately this is deeply > engrained in the PSK culture. > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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In reply to this post by Jon Perelstein
Guys,
This rational is bogus. The PSK users have to get used to decoding one signal at a time with narrow filters if that's what is necessary. To expect to have 2 or 3 KHz free of strong signals is crazy. Dealing with this reality puts the burden on the receiving end. No way can you control what the rest of the wold does. This isn't the Magic Kingdom. Given that PSK is a narrow bandwidth mode, why not use that to your advantage? Other modes deal with strong adjacent signals, why not PSK? You bought a K3 for its high dynamic range and high adjacent signal handling capability. Why not use it for this purpose? Of course the argument ignores all the laws of physics and propagation. I suggest you run some VOACAP prediction calculations with 25 watts and look at what you can't work with 25-75 watts. You may not be interested in working the other side of the world, but others are. PSK isn't magic. 73 de Brian/K3KO On 5/1/2012 11:46 PM, Jon Perelstein wrote: > Eric KG6MZS asked why wouldn't you run more than 70w on PSK > > Because with the close spacing of signals in the various PSK sub-bands, a > signal of more than about 50watts will completely annihilate all the other > PSK signals and make that sub-band unusable for everyone else. The rule of > thumb for being polite on PSK is to operate 25-30w max. I won't claim that > there aren't some who are operating more (you Cuban stations know who you > are), but many/most of us will avoid QSOs with people who are obviously > running 50w+ > > 73s > Jon, WB2RYV > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > > > ----- > No virus found in this message. > Checked by AVG - www.avg.com > Version: 10.0.1424 / Virus Database: 2411/4972 - Release Date: 05/01/12 > > > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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In reply to this post by alsopb
Oh brother!
----- Original Message ----- From: "briana" <[hidden email]> To: <[hidden email]> Sent: Wednesday, May 02, 2012 7:45 AM Subject: Re: [Elecraft] question for psk users > Guys, > > This rational is bogus. The PSK users have to get used to decoding one > signal at a time with narrow filters if that's what is necessary. To > expect to have 2 or 3 KHz free of strong signals is crazy. > > Dealing with this reality puts the burden on the receiving end. No way > can you control what the rest of the wold does. This isn't the Magic > Kingdom. > > Given that PSK is a narrow bandwidth mode, why not use that to your > advantage? > > Other modes deal with strong adjacent signals, why not PSK? > > You bought a K3 for its high dynamic range and high adjacent signal > handling capability. Why not use it for this purpose? > > Of course the argument ignores all the laws of physics and > propagation. I suggest you run some VOACAP prediction calculations > with 25 watts and look at what you can't work with 25-75 watts. You > may not be interested in working the other side of the world, but others > are. > > PSK isn't magic. > > 73 de Brian/K3KO > > > > > > On 5/1/2012 11:46 PM, Jon Perelstein wrote: >> Eric KG6MZS asked why wouldn't you run more than 70w on PSK >> >> Because with the close spacing of signals in the various PSK sub-bands, >> a >> signal of more than about 50watts will completely annihilate all the >> other >> PSK signals and make that sub-band unusable for everyone else. The rule >> of >> thumb for being polite on PSK is to operate 25-30w max. I won't claim >> that >> there aren't some who are operating more (you Cuban stations know who you >> are), but many/most of us will avoid QSOs with people who are obviously >> running 50w+ >> >> 73s >> Jon, WB2RYV >> ______________________________________________________________ >> Elecraft mailing list >> Home: http://mailman.qth.net/mailman/listinfo/elecraft >> Help: http://mailman.qth.net/mmfaq.htm >> Post: mailto:[hidden email] >> >> This list hosted by: http://www.qsl.net >> Please help support this email list: http://www.qsl.net/donate.html >> >> >> ----- >> No virus found in this message. >> Checked by AVG - www.avg.com >> Version: 10.0.1424 / Virus Database: 2411/4972 - Release Date: 05/01/12 >> >> >> > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > 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:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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In reply to this post by KC6CNN
On May 2, 2012, at 7:16, Gerald Manthey <[hidden email]> wrote:
> I find that once I set the my ALC right, Exactly... 73, Joel - W4JBB ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
Re: question for psk users
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In reply to this post by gm3sek
On 5/2/2012 4:05 AM, Ian White GM3SEK wrote: > But PSK's big, unacknowledged 'elephant in the room' will always be > the habit of receiving in a 2.5kHz bandwidth. Unfortunately this is > deeply engrained in the PSK culture. That is a side effect of the "click on the waterfall" mentality driven by software design. One is seeing the same attitudes creeping into operation on other digital modes modes including AFSK. 73, ... Joe, W4TV ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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In reply to this post by John E. Reiser
Agree w/"Oh brother". Guess the panadapter should go also (for those other modes)...
Gpm (sent from iPod Touch - please excuse typos) On May 2, 2012, at 5:23, "John E. Reiser" <[hidden email]> wrote: > Oh brother! > > > ----- Original Message ----- > From: "briana" <[hidden email]> > To: <[hidden email]> > Sent: Wednesday, May 02, 2012 7:45 AM > Subject: Re: [Elecraft] question for psk users > > >> Guys, >> >> This rational is bogus. The PSK users have to get used to decoding one >> signal at a time with narrow filters if that's what is necessary. To >> expect to have 2 or 3 KHz free of strong signals is crazy. >> >> Dealing with this reality puts the burden on the receiving end. No way >> can you control what the rest of the wold does. This isn't the Magic >> Kingdom. >> >> Given that PSK is a narrow bandwidth mode, why not use that to your >> advantage? >> >> Other modes deal with strong adjacent signals, why not PSK? >> >> You bought a K3 for its high dynamic range and high adjacent signal >> handling capability. Why not use it for this purpose? >> >> Of course the argument ignores all the laws of physics and >> propagation. I suggest you run some VOACAP prediction calculations >> with 25 watts and look at what you can't work with 25-75 watts. You >> may not be interested in working the other side of the world, but others >> are. >> >> PSK isn't magic. >> >> 73 de Brian/K3KO >> >> >> >> >> >> On 5/1/2012 11:46 PM, Jon Perelstein wrote: >>> Eric KG6MZS asked why wouldn't you run more than 70w on PSK >>> >>> Because with the close spacing of signals in the various PSK sub-bands, >>> a >>> signal of more than about 50watts will completely annihilate all the >>> other >>> PSK signals and make that sub-band unusable for everyone else. The rule >>> of >>> thumb for being polite on PSK is to operate 25-30w max. I won't claim >>> that >>> there aren't some who are operating more (you Cuban stations know who you >>> are), but many/most of us will avoid QSOs with people who are obviously >>> running 50w+ >>> >>> 73s >>> Jon, WB2RYV >>> ______________________________________________________________ >>> Elecraft mailing list >>> Home: http://mailman.qth.net/mailman/listinfo/elecraft >>> Help: http://mailman.qth.net/mmfaq.htm >>> Post: mailto:[hidden email] >>> >>> This list hosted by: http://www.qsl.net >>> Please help support this email list: http://www.qsl.net/donate.html >>> >>> >>> ----- >>> No virus found in this message. >>> Checked by AVG - www.avg.com >>> Version: 10.0.1424 / Virus Database: 2411/4972 - Release Date: 05/01/12 >>> >>> >>> >> >> ______________________________________________________________ >> Elecraft mailing list >> Home: http://mailman.qth.net/mailman/listinfo/elecraft >> Help: http://mailman.qth.net/mmfaq.htm >> Post: mailto:[hidden email] >> >> 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:[hidden email] > > 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:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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In reply to this post by alsopb
Hey Briana,
To extend your philosophy, why not do away with the official sub-bands, too? Work CW everywhere, SSB everywhere, Am and FM everywhere? When one knows where to look for the typo of mode you want to work, life is easier. Having to scour the whole band for PSK signals makes no sense to me - or RTTY, or packet, or CW. Monty K2DLJ On May 2, 2012, at 7:45 AM, briana wrote: > Guys, > > This rational is bogus. The PSK users have to get used to decoding one > signal at a time with narrow filters if that's what is necessary. To > expect to have 2 or 3 KHz free of strong signals is crazy. > > Dealing with this reality puts the burden on the receiving end. No way > can you control what the rest of the wold does. This isn't the Magic > Kingdom. > > Given that PSK is a narrow bandwidth mode, why not use that to your > advantage? > > Other modes deal with strong adjacent signals, why not PSK? > > You bought a K3 for its high dynamic range and high adjacent signal > handling capability. Why not use it for this purpose? > > Of course the argument ignores all the laws of physics and > propagation. I suggest you run some VOACAP prediction calculations > with 25 watts and look at what you can't work with 25-75 watts. You > may not be interested in working the other side of the world, but others > are. > > PSK isn't magic. > > 73 de Brian/K3KO > > > > > > On 5/1/2012 11:46 PM, Jon Perelstein wrote: >> Eric KG6MZS asked why wouldn't you run more than 70w on PSK >> >> Because with the close spacing of signals in the various PSK sub-bands, a >> signal of more than about 50watts will completely annihilate all the other >> PSK signals and make that sub-band unusable for everyone else. The rule of >> thumb for being polite on PSK is to operate 25-30w max. I won't claim that >> there aren't some who are operating more (you Cuban stations know who you >> are), but many/most of us will avoid QSOs with people who are obviously >> running 50w+ >> >> 73s >> Jon, WB2RYV >> ______________________________________________________________ >> Elecraft mailing list >> Home: http://mailman.qth.net/mailman/listinfo/elecraft >> Help: http://mailman.qth.net/mmfaq.htm >> Post: mailto:[hidden email] >> >> This list hosted by: http://www.qsl.net >> Please help support this email list: http://www.qsl.net/donate.html >> >> >> ----- >> No virus found in this message. >> Checked by AVG - www.avg.com >> Version: 10.0.1424 / Virus Database: 2411/4972 - Release Date: 05/01/12 >> >> >> > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > 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:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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In reply to this post by Glen, W6GJB
You are assuming that everyone has the luxury of narrow roofing
filters and can filter out the week and reject unwanted strong signals. most PSK stations are not blessed with a K3 and are not able to suppress strong signals. before I had a K3 2.4 was the narrowes I could do. most afordable rigs today still stop at 3khz (FT950) and some even wider. You should use as little power as possible to conduct your QSO. where I come from that is the law. using high power to conduct a PSK31 qso is rarely necessary. most other PSK users are running less than 30 W and if you can hear them you probably don't need 100+ watts to talk back. I agree that it is needed in some cases but one should only shout when you need to and talk normal or even whisper if you can. David Moes VE3DVY > > The reason why a strong signal will "annihilate all the other PSK > signals" is that most users are trying to receive an entire 2.5kHz > bandwidth in one gulp. This means that even one strong signal within > that bandwidth will activate the AGC and drive all the other signals > down. > > Regrettably most PSK users don't understand what is happening, so they > have to rationalize it into simpler terms like "It's a crime to be > loud." ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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In reply to this post by Glen, W6GJB
You are assuming that everyone has the luxury of narrow roofing filters and can filter out the week and reject unwanted strong signals. most PSK stations are not blessed with a K3 and are not able to suppress strong signals. before I had a K3 2.4 was the narrowes I could do. most afordable rigs today still stop at 3khz (FT950) and some even wider. You should use as little power as possible to conduct your QSO. where I come from that is the law. using high power to conduct a PSK31 qso is rarely necessary. most other PSK users are running less than 30 W and if you can hear them you probably don't need 100+ watts to talk back. I agree that it is needed in some cases but one should only shout when you need to and talk normal or even whisper if you can. David Moes VE3DVY On Wednesday 02/05/2012 at 4:07 am, Ian White GM3SEK wrote: > > The reason why a strong signal will "annihilate all the other PSK > signals" is that most users are trying to receive an entire 2.5kHz > bandwidth in one gulp. This means that even one strong signal within > that bandwidth will activate the AGC and drive all the other signals > down. > > Regrettably most PSK users don't understand what is happening, so they > have to rationalize it into simpler terms like "It's a crime to be > loud." Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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In reply to this post by alsopb
Brian,
You are right! Now people will say, "look I worked this dx with 25 watts, so that is all you need". That translates to "you should only work the parts of the world to which the band is really, really open. Let the band tell you whom you should work". That is a mindset that can be fine for someone with a lot of empty space in their dxcc list, but amateur radio in general does not expect you to have a particular mindset like that. It may fit well for many newer hams that are also oriented toward digital modes because they are young and prefer relatively modern technologies. If they are expecting in the long run to just pick off a few more countries when conditions dictate, and eventually catch up with those who use the power needed to get the desired communication now, they might face negative surprises though. A few years ago QEX had a very technical article that examined various digital modes in the presence of simulated noise and propagation distortions. A simplified summary: Some kinds of signal distortions that are common with polar propagation are extremely detrimental to psk-31. Although psk is reputed to require much less power than other modes such as RTTY, under those polar propagation conditions RTTY proved vastly more successful for the same power level. It seems to me that RTTY is now much more popular than it was years ago. Could it be that people have found out that the fabulous psk dx results often cited (and which I too have experienced) do not reflect a general ability to work all dx locations? Let me add a subjective observation (opportunity for debate!): After having had only a few home qth's, it seems to me that a given qth (large area, not street address) favors propagation to certain other areas. Being near the west coast, I am not at all surprised at seeing good propagation to JA and NZ, with bounces on salt water. A little more surprising is the fact that propagation to Washington State seems to be favored from my Phoenix area. (I am using a beam, so fixed antenna lobes is not the answer.) Anyway, my point is this: If everyone has favored propagation paths, for one reason or another, one can either focus on the easy directions, or use more power. Surely that applies to psk like any other mode. 73, Erik K7TV -----Original Message----- From: [hidden email] [mailto:[hidden email]] On Behalf Of briana Sent: Wednesday, May 02, 2012 4:46 AM To: [hidden email] Subject: Re: [Elecraft] question for psk users Guys, This rational is bogus. The PSK users have to get used to decoding one signal at a time with narrow filters if that's what is necessary. To expect to have 2 or 3 KHz free of strong signals is crazy. Dealing with this reality puts the burden on the receiving end. No way can you control what the rest of the wold does. This isn't the Magic Kingdom. Given that PSK is a narrow bandwidth mode, why not use that to your advantage? Other modes deal with strong adjacent signals, why not PSK? You bought a K3 for its high dynamic range and high adjacent signal handling capability. Why not use it for this purpose? Of course the argument ignores all the laws of physics and propagation. I suggest you run some VOACAP prediction calculations with 25 watts and look at what you can't work with 25-75 watts. You may not be interested in working the other side of the world, but others are. PSK isn't magic. 73 de Brian/K3KO ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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In reply to this post by alsopb
At 07:45 AM 5/2/2012 -0400, you wrote:
Hi, Brian is right. Just as you should drive according to conditions you should operate according to conditions. Under certain propagation conditions all signals are received within a narrow signal strength range. Under these conditions it possible to set the receiver to operate with a wide 3 khz BW and click and read many PSK signals at the same time with the ability to pounce when a QSO ends. These conditions are not due to all the stations operating at 20W ERP .... and almost any receiver works well under these ideal PSK conditions. However more often than not there is a large signal strength range which doesn't allow operation with a 3 khz BW ... and the difference in station signal strength at the receiver is most often due to differences in propagation rather than the power the station is running. Under these conditions the operator needs a better receiver and an operating practice that is more 'nimble' hi hi. As Brian put it you can't change propagation nor can you control the power the other operator is using or the direction he points his directional antenna hi hi. If you want to check the PSK band during a time with both strong and weak signals you need to be able to move and adjust your bandwidth like a maestro !! A pan adapter is a great tool under these conditions. Of course one could simply stay narrow and call CQ ... but it is more fun to use the dodge and pounce technique hihi Jim, VE3CI >Guys, > >This rational is bogus. The PSK users have to get used to decoding one >signal at a time with narrow filters if that's what is necessary. To >expect to have 2 or 3 KHz free of strong signals is crazy. > >Dealing with this reality puts the burden on the receiving end. No way >can you control what the rest of the wold does. This isn't the Magic >Kingdom. > >Given that PSK is a narrow bandwidth mode, why not use that to your >advantage? > >Other modes deal with strong adjacent signals, why not PSK? > >You bought a K3 for its high dynamic range and high adjacent signal >handling capability. Why not use it for this purpose? > >Of course the argument ignores all the laws of physics and >propagation. I suggest you run some VOACAP prediction calculations >with 25 watts and look at what you can't work with 25-75 watts. You >may not be interested in working the other side of the world, but others >are. > >PSK isn't magic. > >73 de Brian/K3KO > > > > > >On 5/1/2012 11:46 PM, Jon Perelstein wrote: > > Eric KG6MZS asked why wouldn't you run more than 70w on PSK > > > > Because with the close spacing of signals in the various PSK sub-bands, a > > signal of more than about 50watts will completely annihilate all the other > > PSK signals and make that sub-band unusable for everyone else. The rule of > > thumb for being polite on PSK is to operate 25-30w max. I won't claim that > > there aren't some who are operating more (you Cuban stations know who you > > are), but many/most of us will avoid QSOs with people who are obviously > > running 50w+ > > > > 73s > > Jon, WB2RYV > > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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In reply to this post by Joel Black-2
Further to this, on the RX side of the equation if you vary your RF gain, you can sometimes see PSK traces "pop" out of the noise on your waterfall that you might not have noticed there before. I worked a station last week where I thought there might have been a signal in the noise on my waterfall but wasn't sure, parked my pointer on it and did manage to get bits and pieces of text, but when I adjusted the RF gain down, the noise dropped away exposing his signal more clearly and I was then able to actually work that guy. We were both running about 25-30 watts, he was around 7700 miles away and I have a compromise antenna. The notion of adjusting the RF gain down has been discussed on here before in the context of SSB and CW, but I bring it up again for those who may not have thought to try it with PSK. Now, regarding power, there were other signals near his on my waterfall (even within the confines of my narrowest filter (400)), but none were strong enough to reduce my receiver's sensitivity. Were there someone there running a dirty signal or a lot of power, this QSO would never have happened. 73 & Aloha Dave, AH6TD On May 2, 2012, at 2:50 AM, Joel Black wrote: > On May 2, 2012, at 7:16, Gerald Manthey <[hidden email]> wrote: > >> I find that once I set the my ALC right, > > Exactly... > > 73, > Joel - W4JBB > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > 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:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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In reply to this post by Glen, W6GJB
I have macros built in HRD that allows me to quickly center a PSK RX and
then I pop to mhy 200 hz filter to work them when every the adjacent signals are messing with my decode. I constantly change between many filter choices as necessary via macros in the software. I bought the 200 hz filter last year at Dayton after Wayne spent a few minutes of time with me explaining how to use the filters better to my advangate. Now I don't care what the other guys do because the K3 just does what it does best. ~73 Don KD8NNU On Wed, May 2, 2012 at 7:45 AM, briana wrote: > Guys, > > This rational is bogus. The PSK users have to get used to decoding > one signal at a time with narrow filters if that's what is necessary. > To expect to have 2 or 3 KHz free of strong signals is crazy. > > Dealing with this reality puts the burden on the receiving end. No > way can you control what the rest of the wold does. This isn't the > Magic Kingdom. > > Given that PSK is a narrow bandwidth mode, why not use that to your > advantage? > > Other modes deal with strong adjacent signals, why not PSK? > > You bought a K3 for its high dynamic range and high adjacent signal > handling capability. Why not use it for this purpose? > > Of course the argument ignores all the laws of physics and > propagation. I suggest you run some VOACAP prediction calculations > with 25 watts and look at what you can't work with 25-75 watts. You > may not be interested in working the other side of the world, but > others are. > > PSK isn't magic. > > 73 de Brian/K3KO > > > > > > On 5/1/2012 11:46 PM, Jon Perelstein wrote: >> Eric KG6MZS asked why wouldn't you run more than 70w on PSK >> >> Because with the close spacing of signals in the various PSK >> sub-bands, a >> signal of more than about 50watts will completely annihilate all the >> other >> PSK signals and make that sub-band unusable for everyone else. The >> rule of >> thumb for being polite on PSK is to operate 25-30w max. I won't >> claim that >> there aren't some who are operating more (you Cuban stations know who >> you >> are), but many/most of us will avoid QSOs with people who are >> obviously >> running 50w+ >> >> 73s >> Jon, WB2RYV >> ______________________________________________________________ >> Elecraft mailing list >> Home: http://mailman.qth.net/mailman/listinfo/elecraft >> Help: http://mailman.qth.net/mmfaq.htm >> Post: mailto:[hidden email] >> >> This list hosted by: http://www.qsl.net >> Please help support this email list: http://www.qsl.net/donate.html >> >> >> ----- >> No virus found in this message. >> Checked by AVG - www.avg.com >> Version: 10.0.1424 / Virus Database: 2411/4972 - Release Date: >> 05/01/12 >> >> >> > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > 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:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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