RE: [AMRadio] Re: How can we rid the HF bands of AM ?
> > You like fiddlin', and that's fine. But, for me (and I think some > others here agree) there's nothing finer than saying "rig here is > homebrew" and getting that "man, that's a good sounding rig" report in > return. The feeling is indescribable. You get a lot of bang for the buck with home brew. You get all the fun of planning the design, including things you like such as protection circuits, front panel layout, metering, etc. You get to design it just how you want it. Then you get to select parts, I go with WAY oversize and over rated parts. Then there is the fun of actually building the thing, nice paint, parts placed so they look nice, say in a line and centered, symmetrical panel layout, controls labeled, etc. Then you get to test it, and make any improvements to make it work real well, Then you get to use it, over and over. I am almost all home brew, two tube type superhet receivers, and two and a half transmitters, (the pair of 4d32's rig is half done), home made antenna's. I need to build a multi band exciter deck to drive the various rigs, and an audio driver setup, eq, compression, mixing, mike amp, power output. Then I will be all home brew except for the microphone. The receivers were more fun than anything else, because they are small and easy to work on, a lot less metal work, more experimentation Another advantage to well made home brew is its reliability, since its all been built robustly (unlike commercial 'ham' gear), it just works and works, even after mental burnouts like not connecting the antenna to the correct rig... Brett N2DTS
Re: [AMRadio] Re: How can we rid the HF bands of AM ?
You like fiddlin', and that's fine. But, for me (and I think some others here agree) there's nothing finer than saying "rig here is homebrew" and getting that "man, that's a good sounding rig" report in return. The feeling is indescribable. I can relate to that. First time we cathode-modulated Dennis W5FRS's homebrew 250TH amp with an Altec 1570B tube amp, we were ecstatic over the reports. I think the one that got me was "sounds just like a broadcast station". We did tweek the amp quite a bit to get the modulation linear, It was originally running AB2, and we had to increase the bias and drive, and load it a little less, but it sure did sound sweet. Some pice are here: http://rawfire.torche.com/~opcom/dbrady1/index.html Fire is best served in it's natural state? ;-) Say HI to Dennis for me. I've worked him a few times on 80m CW down at 3.546Mc and once or twice on 7.160Mc AM and just the other day, we -almost- had a QSO on 7.050Mc CW, from my Viking II at around 50w. It's the rig that serves as the exciter for the 250THx250TH rig. I tried to sell a 450TH, appearing as if it was unused, no scratches on the base - asked in here for $50 for it, in the metal spring-loaded shipping frame, in a box. No one bit. Put it on ebay for 7 days, and started it off at 9.95 and it sold for some 3X (plus shipping) what I was asking for it originally, in here. A 450TH is a very specialized tube today. Sometimes it takes just the right buyer. $50's cheep cheep for a new one, I think. I've got SEVERAL 450TL's that are eating up a lot of space in my shack. I could use the money, right now. They all have filament glow. I did go through a few of 5R4's in the modulator bias supply before I figured out that one of the 304TH's had an intermittent short from filament to grid, but only with HV applied. Oddly, whatever happened 'blew up' the filament in the 5R4 before any fuses or overloads could trip, and then the bias supply fuse blew.. This was in a supposedly good 304TH I bought from ebay. Due to the scarcity and high costs of 304TH's, I have changed to 3-500Z's now, and I need to re-do the bias supply for 0-30V instead of 0-300V! I think a 10:1 voltage divider/bleeder drawing about 100mA at 300V should do (The modulator bias power supply is rated 200mA). That way the rig stays more original, and the grid supply now has a 300 ohm resistance! I need to see about locating a 304TH rig I know of. I don't know if it'll ever be put back on the air, by the present caretaker of that rig... and it's just the final section. That thing used be be a pair of 304TH's (or was it TL's, John?) modulated by (4) 813's in push-pull, parallel. I full kilowatt DC input to the final, with something like 1100 or 1200v at 750 or 800mA. Somewhere in that area. As a pulse Radar tube, the 304's will -certainly- handle the current! Just for grins and giggles, try putting 2 50 ohm resistors in series to ground, and then the grid to the center of the two 50 ohm resistors. It's helped other rigs. I will try that. I am not sure of the effect it will have with the grid tank feeding a low resistance load of 100 ohms, but it will point me in the right direction. It provides a voltage divider network. Anything stray, goes to ground. I'm looking at these conditions (they represent much more power than I will legally use, but should be good for figuring. There were no figures for 2500V or less.) Plate Modulated Class C Amplifier [CCS] Plate Voltage . 3000 V Grid No. 2 Voltage 500 V Grid No. 1 Voltage -200 V Peak Grid No. 1 Voltage 340 V Grid No. 1 Current 12 mA Plate Current . 600 mA Grid No. 2 Current 145 mA Driving Power . 12 W Power Output (approx) . 1390 W Maximum Frequency . 110 MHz My question, is from these, how do I figure the impedance of the load presented by the grid circuit to the grid tank? The same way you would for the plate tank. R=E/I R=340v/12mA R=28.3k Ohms The power dissapated is a tad over 4w, so (4) 100kohm, 1-watt resistors with a parasitic choke wired around 'em would be plenty, I would think. Run that in series with the grid drive to the pin. Do the same for G2. Seperate 120v circuits? Yes, indeed COL Tucker apparently did not want to install a big ugly 240V outlet, so he apparently used a pair of 20-amp 120V outlets connected to 240V in the breaker box. Of note in this rig, is that neutral is bonded to ground. period. That is, there is no ground prong on the plugs and it is not possible to separate neutral from ground in this rig without a major rewiring job. So, I will have to take care that I do use a 4-wire grounding 240V plug, and see that I rea
Re: [AMRadio] Re: How can we rid the HF bands of AM ?
Patrick Jankowiak wrote: Hey Geoff, You are right, I won't be totin' the Tucker KW or even the BTA-250.. For me the AM is a hobby and a love for doing things in one of the old and respected ways. No General yet, maybe soon. I have alot of fun just fiddling with them. You like fiddlin', and that's fine. But, for me (and I think some others here agree) there's nothing finer than saying "rig here is homebrew" and getting that "man, that's a good sounding rig" report in return. The feeling is indescribable. The Transmitters/restorations are on hold as I am doing a major clean-out of my lab. Each weekend we have been hauling 800 lbs of junk to the landfill, it is -most- politically incorrect. nothing of interest here, unless someone wants old 9-track computer tapes and stuff like that. You never know what someone will buy on ebay. At worst, it hangs around your shop another week. At best, you have something that someone else thinks is an antique relic and is 'just the part' they need to finish out their collection. *shrug* hey, it could happen ;-) I tried to sell a 450TH, appearing as if it was unused, no scratches on the base - asked in here for $50 for it, in the metal spring-loaded shipping frame, in a box. No one bit. Put it on ebay for 7 days, and started it off at 9.95 and it sold for some 3X (plus shipping) what I was asking for it originally, in here. The worst than can happen is, it hangs out for a week. For what was lost, well that is true to a degree and 3 or 6 dB does not make that much difference at the other end, but I guess I am looking at the old Tucker rig and knowing its audio and RF power supplies are good for 3KW DC each. COL Tucker built it for military communications from Dallas to Austin. I mean, the thing was/is capable of who knows how much audio input on top of the KW DC. I'm thinking of the peak power. It just seems a shame to idle it out along the wireless in 2nd gear. The upside is that it will probably last forever. Think of the money you'll save on spares ;-) The status on that beast is that there is a parasitic oscillation in the final's grid circuit, between the 4-1000 control and screen grids, at about 140MHz. Plate tuning, current, and neuralization setting do not matter or vary much at all with this issue and the grid current and screen current interact alot. I found that a 50 ohm resistor in series with the grid helped. Maybe I need to increase that value or I don't know.. The screen grid is heavily bypassed directly at the G2 terminals on the socket, and an RF choke is optionally in series with the screen to the chassis connector to no effect. This oscillation happens no matter if the grid drive connector is shorted, open, or terminated, so this tells me it is in the control grid circuit somewhere. Nothing's been changed from the original design there, so it is further mysterious. Just for grins and giggles, try putting 2 50 ohm resistors in series to ground, and then the grid to the center of the two 50 ohm resistors. It's helped other rigs. Also, I need to rig a 220V 30A outlet and power cord for it. I keep popping the 120V breaker when running up the final and modulation sides together (the unit has two 120V plugs presently). Seperate 120v circuits? As far as audio, I'm willing to help anyone who wants better quality sound from their AM rig. I'm not a great RF expert at all but I am OK with increasing the fidelity/reducing distortion in audio amps. But.. one works hand in hand with the other. In fact, John/WA5BXO and I have been discussing (at length, and credit to John for sticking with me and my dumb questions ;-)) audio, it's effects on the transmitted carrier, how much voltage is neeed to fully modulate the carrier and what is needed in the way of a reactor to sucessfully couple the audio to the B+ line to the final amplifier. This conversation encompassed power supplies, through the modulator and the final. All components are cruicial. John and I also talk, from time to time, at length about asymetrical audio. I've achieved it, somewhat. Sometimes technology is overwhelming. For less than $100, I bought not only a digital camera that takes amazing 3.2megapixel pictures, but it also has a 'movie' mode. No audio, but the movie mode is pretty awesome. "Hel-l-l-l-l-o test. one, two, three, four." http://w5omr.shacknet.nu:81/~w5omr/pictures/2005-08-08/000_0049.MOV The 'noise' you see is a box-fan at full speed. It was over 100° here, that day. At this moment I'm limited to NVIS type antennas, but I have a tower to put up. another project. I hope a tower will get me better shortwave listening due to a higher antenna (and give me a place to put a 6M beam for FM). Mike/WA5CMI has been on 6m lately. He's in Garland, not too far from you. Maybe y'all could hook up and check out 6m together. he's probably monitoring either 50.4 or 50.125 - give a holler for
Re: [AMRadio] Re: How can we rid the HF bands of AM ?
peter markavage wrote: Don't see this as "silly" but as imperative, or something similar to it, as vital to the amateur radio service as we move further into the 21st century. But, to get back to the real thread, Don, KYV, said it about as clear as you can get it: "Run a certain plate voltage and load the transmitter enough that plate voltage multiplied by plate current calculates to 1000 watts. Carefully watch the scope so that the negative modulation peaks just barely approach baseline, and make sure the positive peaks do not show evidence of flat-topping. Simple laws of physics" It's not rocket science. Pete, wa2cwa Patrick was speaking of legalities. I'm sure all of us here, know how to load a rig to a kW. What he's asking is: How do we go about getting our old '1kW DC Input to the final' rating back from the Feds? And, as noble as that sounds, I'm afraid that you'd have a better chance of picking up a 250TH at your local corner store market. You know, the one that has a tube-tester in it? Just like those days of tube testers in the local stores, so too are the days of running a legal 1kW DC input power level gone. --- 73 = Best Regards, -Geoff/W5OMR
Re: [AMRadio] Re: How can we rid the HF bands of AM ?
Not rocket science at all, just the fact that most people don't have a scope, and many of them do not understand how to read them or where to use them. Get them to understand what a mask it Pete. 73 Jim W5JO Don't see this as "silly" but as imperative, or something similar to it, as vital to the amateur radio service as we move further into the 21st century. But, to get back to the real thread, Don, KYV, said it about as clear as you can get it: "Run a certain plate voltage and load the transmitter enough that plate voltage multiplied by plate current calculates to 1000 watts. Carefully watch the scope so that the negative modulation peaks just barely approach baseline, and make sure the positive peaks do not show evidence of flat-topping. Simple laws of physics" It's not rocket science. Pete, wa2cwa
Re: [AMRadio] Re: How can we rid the HF bands of AM ?
Don't see this as "silly" but as imperative, or something similar to it, as vital to the amateur radio service as we move further into the 21st century. But, to get back to the real thread, Don, KYV, said it about as clear as you can get it: "Run a certain plate voltage and load the transmitter enough that plate voltage multiplied by plate current calculates to 1000 watts. Carefully watch the scope so that the negative modulation peaks just barely approach baseline, and make sure the positive peaks do not show evidence of flat-topping. Simple laws of physics" It's not rocket science. Pete, wa2cwa On Sun, 7 Aug 2005 17:53:34 -0500 "Jim Wilhite" <[EMAIL PROTECTED]> writes: > No Pete, only the ARRL can be silly. Bandwidth proposal > - Original Message - > From: "peter markavage" <[EMAIL PROTECTED]> > To: > Sent: Sunday, August 07, 2005 4:47 PM > Subject: Re: [AMRadio] Re: How can we rid the HF bands of AM ? > > > >I can see Congress spending the time, with all their own local > issues and > > world issues, to petition the FCC to give hams more RF. Now we're > being > > silly. > > Pete, wa2cwa > > > > On Sun, 07 Aug 2005 16:12:38 -0500 Geoff <[EMAIL PROTECTED]> > writes: > >> Jim Wilhite wrote: > >> > >> >> [EMAIL PROTECTED] wrote: > >> >> > >> >> > >> >>> how do we get the old "KW Input" for AM back now? > >> >>> probably impossible.. > >> >> > >> >> > >> >>> You might start with your congresspersin. > >> >> > >> > > >> > We have a couple of hams in congress. Why not email them, > >> especially > >> > hams in their district. One very good argument for going to DC > > >> input > >> > is the accuracy of measurement. > >> > >> > >> Amen. Hey, I'm all for running a full kW DC input again, and > more > >> power > >> to those of y'all that can pull it off. I'm plagued with a bad > rash > >> of > >> neighboritis. > >> > >> But, still.. for accuracy of measurment, how hard is it to > calculate > >> > >> 500w DC input? (uh, gee.. 2500v x 200mA =... Cornbread?) ;-) > >> > >> Besides, Jim - given that Class C finals are 75% efficient (on > >> average), > >> what's 75% of 500w? > >> > >> (just to point you in the right direction, 500w DC input is > -half- > >> of > >> what we -could- run, given that 1500w PEP is 'generically > >> considered' to > >> be 100% modulation of the product of 75% of a 500w carrier.) > >> > >> Can I be an instructor now, Don? ;-) > >> > >> So, we're NOT down 25% of what we -could- run as some lamented.. > > >> it's > >> realistically only 50%. > > >> The saying back in those days was: > >> "They'll get my kilowatt when they pry my D-104 from my cold dead > > >> fingers" > >>and > >> "When AM Kilowatts are outlawed, then only outlaws will be > running > >> AM > >> Kilowatts". > >> (which in some cases isn't that far from the truth ;-)) > >> > >> Think about it, fellas. Asymetrical Audio. Run 500w DC input - > > >> have > >> enough power to modulate the carrier - run 3kW pep > >> output, and tell the eff cee cee that "my carrier power is 375w! > > >> I'm > >> LEGAL!" No, really - DO IT! Currently, (as Jim aptly > >> pointed out) who's gonna measure? How could that measurment > stand > >> up in > >> court? Where are they measuring, at the Final, > >> or at the Antenna? > >> > >> I think, that if a good, solid, well-built/constructed AM rig was > > >> operated in a gentlemany manner, then that person doesn't draw > >> that much negative attention to himself and be nice, polite.. > >> Gentlemanly (sorry, I just ain't heard no female AM'ers) and > >> you'll > >> fly under the radar as long as you maintain. And, you could be > >> running > >> a kW DC input. (which, btw, is 750w of carrier, and > >> only 3kW PEP if modulated with a sine-wave to 100% but who talks > in > >> > >> sine-waves?) > >> > >> --- > >> 73 = Best Regards, > >> -Geoff/W5OMR
Re: [AMRadio] Re: How can we rid the HF bands of AM ?
No Pete, only the ARRL can be silly. Bandwidth proposal - Original Message - From: "peter markavage" <[EMAIL PROTECTED]> To: Sent: Sunday, August 07, 2005 4:47 PM Subject: Re: [AMRadio] Re: How can we rid the HF bands of AM ? I can see Congress spending the time, with all their own local issues and world issues, to petition the FCC to give hams more RF. Now we're being silly. Pete, wa2cwa On Sun, 07 Aug 2005 16:12:38 -0500 Geoff <[EMAIL PROTECTED]> writes: Jim Wilhite wrote: >> [EMAIL PROTECTED] wrote: >> >> >>> how do we get the old "KW Input" for AM back now? >>> probably impossible.. >> >> >>> You might start with your congresspersin. >> > > We have a couple of hams in congress. Why not email them, especially > hams in their district. One very good argument for going to DC input > is the accuracy of measurement. Amen. Hey, I'm all for running a full kW DC input again, and more power to those of y'all that can pull it off. I'm plagued with a bad rash of neighboritis. But, still.. for accuracy of measurment, how hard is it to calculate 500w DC input? (uh, gee.. 2500v x 200mA =... Cornbread?) ;-) Besides, Jim - given that Class C finals are 75% efficient (on average), what's 75% of 500w? (just to point you in the right direction, 500w DC input is -half- of what we -could- run, given that 1500w PEP is 'generically considered' to be 100% modulation of the product of 75% of a 500w carrier.) Can I be an instructor now, Don? ;-) So, we're NOT down 25% of what we -could- run as some lamented.. it's realistically only 50%. The saying back in those days was: "They'll get my kilowatt when they pry my D-104 from my cold dead fingers" and "When AM Kilowatts are outlawed, then only outlaws will be running AM Kilowatts". (which in some cases isn't that far from the truth ;-)) Think about it, fellas. Asymetrical Audio. Run 500w DC input - have enough power to modulate the carrier - run 3kW pep output, and tell the eff cee cee that "my carrier power is 375w! I'm LEGAL!" No, really - DO IT! Currently, (as Jim aptly pointed out) who's gonna measure? How could that measurment stand up in court? Where are they measuring, at the Final, or at the Antenna? I think, that if a good, solid, well-built/constructed AM rig was operated in a gentlemany manner, then that person doesn't draw that much negative attention to himself and be nice, polite.. Gentlemanly (sorry, I just ain't heard no female AM'ers) and you'll fly under the radar as long as you maintain. And, you could be running a kW DC input. (which, btw, is 750w of carrier, and only 3kW PEP if modulated with a sine-wave to 100% but who talks in sine-waves?) --- 73 = Best Regards, -Geoff/W5OMR __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
RE: [AMRadio] Re: How can we rid the HF bands of AM ?
From: Patrick Jankowiak <[EMAIL PROTECTED]> how do we get the old "KW Input" for AM back now? Run a certain plate voltage and load the transmitter enough that plate voltage multiplied by plate current calculates to 1000 watts. Carefully watch the scope so that the negative modulation peaks just barely approach baseline, and make sure the positive peaks do not show evidence of flat-topping. Simple laws of physics. kyv
Re: [AMRadio] Re: How can we rid the HF bands of AM ?
Jim Wilhite wrote: My point exactly Geoff: PEP is a calculation for most hams who don't have a scope (most don't). Input is a different story. RMS reading can be taken off meters with a single tone signal and using the plate voltage times the current gives you a 10% (depending on the meters and shunt) accuracy. This, however, is not true of PEP, as you have so aptly pointed out. Even today's PEP wattmeters are not that accurate (better than in the past, but not good enough). After all who really understands that when calculating the RF safety margins, use of 33 1/3% duty cycle for SSB is appropriate? Well, seriously - as the man said, petitioning the FCC for more RF power out for Ham Radio operators is like screwing for virginity. I understand fighting to preserve freedom, but the analogy is lost in translation by the tree-huggers, hippy's, love-children, etc... when they say that fighting for peace is like screwing for virginity. It was kinda neat however, glomming the websites for the San Fransisco event a month ago, where a bunch of women protested the war, with their "Boobs, not Bombs" slogan, and showed up, topless, someplace downtown San Fransisco. (where else ~sigh~ ) (don't ask me for the url - google knows. ;-)) --- 73 = Best Regards, -Geoff/W5OMR
Re: [AMRadio] Re: How can we rid the HF bands of AM ?
I can see Congress spending the time, with all their own local issues and world issues, to petition the FCC to give hams more RF. Now we're being silly. Pete, wa2cwa On Sun, 07 Aug 2005 16:12:38 -0500 Geoff <[EMAIL PROTECTED]> writes: > Jim Wilhite wrote: > > >> [EMAIL PROTECTED] wrote: > >> > >> > >>> how do we get the old "KW Input" for AM back now? > >>> probably impossible.. > >> > >> > >>> You might start with your congresspersin. > >> > > > > We have a couple of hams in congress. Why not email them, > especially > > hams in their district. One very good argument for going to DC > input > > is the accuracy of measurement. > > > Amen. Hey, I'm all for running a full kW DC input again, and more > power > to those of y'all that can pull it off. I'm plagued with a bad rash > of > neighboritis. > > But, still.. for accuracy of measurment, how hard is it to calculate > > 500w DC input? (uh, gee.. 2500v x 200mA =... Cornbread?) ;-) > > Besides, Jim - given that Class C finals are 75% efficient (on > average), > what's 75% of 500w? > > (just to point you in the right direction, 500w DC input is -half- > of > what we -could- run, given that 1500w PEP is 'generically > considered' to > be 100% modulation of the product of 75% of a 500w carrier.) > > Can I be an instructor now, Don? ;-) > > So, we're NOT down 25% of what we -could- run as some lamented.. > it's > realistically only 50%. > > The saying back in those days was: > "They'll get my kilowatt when they pry my D-104 from my cold dead > fingers" >and > "When AM Kilowatts are outlawed, then only outlaws will be running > AM > Kilowatts". > (which in some cases isn't that far from the truth ;-)) > > Think about it, fellas. Asymetrical Audio. Run 500w DC input - > have > enough power to modulate the carrier - run 3kW pep > output, and tell the eff cee cee that "my carrier power is 375w! > I'm > LEGAL!" No, really - DO IT! Currently, (as Jim aptly > pointed out) who's gonna measure? How could that measurment stand > up in > court? Where are they measuring, at the Final, > or at the Antenna? > > I think, that if a good, solid, well-built/constructed AM rig was > operated in a gentlemany manner, then that person doesn't draw > that much negative attention to himself and be nice, polite.. > Gentlemanly (sorry, I just ain't heard no female AM'ers) and > you'll > fly under the radar as long as you maintain. And, you could be > running > a kW DC input. (which, btw, is 750w of carrier, and > only 3kW PEP if modulated with a sine-wave to 100% but who talks in > > sine-waves?) > > --- > 73 = Best Regards, > -Geoff/W5OMR
Re: [AMRadio] Re: How can we rid the HF bands of AM ?
You want high efficient AM transmitters, go here: http://www.classeradio.com/ Pete, wa2cwa On Sun, 07 Aug 2005 15:21:15 -0500 Geoff <[EMAIL PROTECTED]> writes: > > The way *I* see it, we only lost 500w. Run your AM rig at 500w DC > input > to the final, and let the audio fall where it may. > Perhaps some of the guys on the air will get more interested in > making > their final more efficient - find better ways to modulate their rigs > - > get some of the trashier sounding rigs off the air, by -helping- > that > ham with working on -his- rig. Get the ol' commraderie going, > again. > > I can build stuff... I just need to have someone around to talk to, > joke > with, laugh at.. er, with (hehe) .. I'm just not a good > self-motivator. > Besides, working a project together is what fosters friendships and > > forges bonds that keep you tied in a hobby together, for a > lifetime. > > Speaking of which, Patrick... you ever get your General Class > license? > I can't -wait- to hear some of that Big Iron you've got up there, on > the > air. > > > --- > 73 = Best Regards, > -Geoff/W5OMR
Re: [AMRadio] Re: How can we rid the HF bands of AM ?
My point exactly Geoff: PEP is a calculation for most hams who don't have a scope (most don't). Input is a different story. RMS reading can be taken off meters with a single tone signal and using the plate voltage times the current gives you a 10% (depending on the meters and shunt) accuracy. This, however, is not true of PEP, as you have so aptly pointed out. Even today's PEP wattmeters are not that accurate (better than in the past, but not good enough). After all who really understands that when calculating the RF safety margins, use of 33 1/3% duty cycle for SSB is appropriate? 73 Jim W5JO Amen. Hey, I'm all for running a full kW DC input again, and more power to those of y'all that can pull it off. I'm plagued with a bad rash of neighboritis. But, still.. for accuracy of measurment, how hard is it to calculate 500w DC input? (uh, gee.. 2500v x 200mA =... Cornbread?) ;-) Besides, Jim - given that Class C finals are 75% efficient (on average), what's 75% of 500w? (just to point you in the right direction, 500w DC input is -half- of what we -could- run, given that 1500w PEP is 'generically considered' to be 100% modulation of the product of 75% of a 500w carrier.)
Re: [AMRadio] Re: How can we rid the HF bands of AM ?
And then how about a nice 5 or 6 DB antenna? A nice 4 sq. on 75 won't cost much more than a 1KW, 100% mod. rig, is steerable, and legal. Byron, W3WKR
Re: [AMRadio] Re: How can we rid the HF bands of AM ?
Jim Wilhite wrote: We have a couple of hams in congress. Why not email them, especially hams in their district. One very good argument for going to DC input is the accuracy of measurement. Or maybe just tell them that running 1KW AM will "help BPL"...they seem to go for logic like that... 73 Bob W9RAN
Re: [AMRadio] Re: How can we rid the HF bands of AM ?
Jim Wilhite wrote: [EMAIL PROTECTED] wrote: how do we get the old "KW Input" for AM back now? probably impossible.. You might start with your congresspersin. We have a couple of hams in congress. Why not email them, especially hams in their district. One very good argument for going to DC input is the accuracy of measurement. Amen. Hey, I'm all for running a full kW DC input again, and more power to those of y'all that can pull it off. I'm plagued with a bad rash of neighboritis. But, still.. for accuracy of measurment, how hard is it to calculate 500w DC input? (uh, gee.. 2500v x 200mA =... Cornbread?) ;-) Besides, Jim - given that Class C finals are 75% efficient (on average), what's 75% of 500w? (just to point you in the right direction, 500w DC input is -half- of what we -could- run, given that 1500w PEP is 'generically considered' to be 100% modulation of the product of 75% of a 500w carrier.) Can I be an instructor now, Don? ;-) So, we're NOT down 25% of what we -could- run as some lamented.. it's realistically only 50%. The saying back in those days was: "They'll get my kilowatt when they pry my D-104 from my cold dead fingers" and "When AM Kilowatts are outlawed, then only outlaws will be running AM Kilowatts". (which in some cases isn't that far from the truth ;-)) Think about it, fellas. Asymetrical Audio. Run 500w DC input - have enough power to modulate the carrier - run 3kW pep output, and tell the eff cee cee that "my carrier power is 375w! I'm LEGAL!" No, really - DO IT! Currently, (as Jim aptly pointed out) who's gonna measure? How could that measurment stand up in court? Where are they measuring, at the Final, or at the Antenna? I think, that if a good, solid, well-built/constructed AM rig was operated in a gentlemany manner, then that person doesn't draw that much negative attention to himself and be nice, polite.. Gentlemanly (sorry, I just ain't heard no female AM'ers) and you'll fly under the radar as long as you maintain. And, you could be running a kW DC input. (which, btw, is 750w of carrier, and only 3kW PEP if modulated with a sine-wave to 100% but who talks in sine-waves?) --- 73 = Best Regards, -Geoff/W5OMR
Re: [AMRadio] Re: How can we rid the HF bands of AM ?
[EMAIL PROTECTED] wrote: how do we get the old "KW Input" for AM back now? probably impossible.. You might start with your congresspersin. We have a couple of hams in congress. Why not email them, especially hams in their district. One very good argument for going to DC input is the accuracy of measurement. 73 Jim W5JO
Re: [AMRadio] Re: How can we rid the HF bands of AM ?
[EMAIL PROTECTED] wrote: how do we get the old "KW Input" for AM back now? probably impossible.. You might start with your congresspersin. The FCC guy gave up on trying to get AM off the bands, quoting the same thing, and we're still here. Calling up your congress-critter might not be a bad idea, but what are we effectivly going to use to argue that we -need- to have 1kWDC input to the final, these days? If there's an emergency, you -certainly- won't be totin' yer RCA BTA1R out to a tornado/hurricane/(un)natural disaster site to setup emergency communications... and the remote site surely doesn't lend itself well to the kind of power requirements needed by an AM transmitter of any heft. The way *I* see it, we only lost 500w. Run your AM rig at 500w DC input to the final, and let the audio fall where it may. Perhaps some of the guys on the air will get more interested in making their final more efficient - find better ways to modulate their rigs - get some of the trashier sounding rigs off the air, by -helping- that ham with working on -his- rig. Get the ol' commraderie going, again. I can build stuff... I just need to have someone around to talk to, joke with, laugh at.. er, with (hehe) .. I'm just not a good self-motivator. Besides, working a project together is what fosters friendships and forges bonds that keep you tied in a hobby together, for a lifetime. Speaking of which, Patrick... you ever get your General Class license? I can't -wait- to hear some of that Big Iron you've got up there, on the air. --- 73 = Best Regards, -Geoff/W5OMR
Re: [AMRadio] Re: How can we rid the HF bands of AM ?
You might start with your congresspersin. 73, John, W4AWM
