RE: [AMRadio] UTC S-21 specification
Complete info here. http://www.amwindow.org/tech/htm/modtran/utc/sseries.htm -Original Message- > From: Mark Foltarz > Sent: Thursday, July 25, 2002 9:59 PM > > Does any one happen to have the specs for a UTC S-21 ?
Re: [AMRadio] Audio response and Long distant QSO's (was: Suggestions Please)
Hello Jeff: Nice to hear from you.My website has the replys mixed up so I hope this dosnt go world wide, HI. Will look forward to working you again especially on 160 this winter (?) 73 for now. DE Charlie, K0NG Quoting "Jeffrey J. May" <[EMAIL PROTECTED]>: > Hi Charlie, > I am now living in SW Miss..about 130 miles NE of New Orleans...hope all > is well with you..73..Jeff..W0XV..ex W0ONM > - Original Message - > From: <[EMAIL PROTECTED]> > To: > Sent: Wednesday, July 24, 2002 8:33 PM > Subject: Re: [AMRadio] Audio response and Long distant QSO's (was: > Suggestions Please) > > > > > > > > Jeff: You are too logical!! Wideband for strong signals, narrowband for > > weak signals. Almost all AM signals in Nebraska are weak so I > > guess that makes me "narrow minded". By the way, there are several > > systems that automatically adjust either audio or IF bandwidth > > depending upon signal strength (AVC) or signal to noise ratio. > > I have used both until DSP came along. Good luck in your > discussion. > > > > 73 DE Charlie, K0NG > > > > Quoting Jeff Edmonson <[EMAIL PROTECTED]>: > > > > > > > > > > > : If you have to ask, then you are probably using too much. If you are > > > : listening, you probably aren't using enough. If all you think about > is > > > : comparing AM to SSB, then you are just looking for a silly argument. > > > > > > Trust me, Bill, this is not someone "trolling" for a fight in a group. > > > > > > I'm serious when I ask, though - what's the purpose of trying to run > > > audio, starting at 50Hz, on a noisy HF band like 160, 75 or 40m? > > > > > > honestly, from across the nation, those transmitters who have that much > > > low-end response are the same people who want that low-end response > > > enhanced, and in periods of QRM/QRN and selective fade, it's more of > > > a determent to be able to copy, than an enjoyable, enhanced audio > > > performance. I'm absolutely sure that the later is the goal intended, > but > > > for talking cross-country on noisy bands, SORRY!, it's just not gonna > > > happen. > > > > > > Now, it's possible to have GREAT audio and still filter and tailor the > > > audio so that it's not out of the passband, such as that of Don Chester, > > > K4KYV. I'm hoping that Don can come in here, and remind me how it > is/was > > > he was peaking the audio at around 3kc, and then rolling the whole thing > > > off at 3.5kc (or slightly higher). And, what's the bottom end? > > > > > > ___ > > > AMRadio mailing list > > > AMRadio@mailman.qth.net > > > http://mailman.qth.net/mailman/listinfo/amradio > > > > > > > > > > > ___ > > AMRadio mailing list > > AMRadio@mailman.qth.net > > http://mailman.qth.net/mailman/listinfo/amradio > > > > ___ > AMRadio mailing list > AMRadio@mailman.qth.net > http://mailman.qth.net/mailman/listinfo/amradio >
Re: [AMRadio] UTC S-21 specification
"UTC Special Series transformers are specifically designed for amateur and popular-priced PA service. These units are finished in a rich, commercial type medum gray enamel. A recessed terminal strip is provided, permitting above chassis or breadboard wiring in addition to standard chassis type." S-21 Universal Modulation, Any Class B primary, Any Class C secondary, 110 watts G7 Case, sold for $21 in 1963. (From Elmar/Masters Catalog) Must say, the input and output impedance rating appears rather strange. No turns radios or impedance specified, nor current ratings. G7 Case: 4-5/8 x 4-5/8 x 5-1/2" 8 lbs. Perhaps someone else has better detail. 73 de Bill, AB6MT [EMAIL PROTECTED] - Original Message - From: "Mark Foltarz" <[EMAIL PROTECTED]> To: Sent: Thursday, July 25, 2002 6:58 PM Subject: [AMRadio] UTC S-21 specification > Hello Group, > > Does any one happen to have the specs for a UTC S-21 ? > > TNX > DE KA4JVY > Mark > > __ > Do You Yahoo!? > Yahoo! Health - Feel better, live better > http://health.yahoo.com > ___ > AMRadio mailing list > AMRadio@mailman.qth.net > http://mailman.qth.net/mailman/listinfo/amradio
Re: [AMRadio] UTC S-21 specification
UTC S-21 specs: Universal Modulation Transformer. Secondary carries class C current. Any modulator tubes to any RF load. 110 Watts, Veritcal mount with hole in chassis required to access connection strip. Original cost $ 18.00 73, W4AWM
[AMRadio] UTC S-21 specification
Hello Group, Does any one happen to have the specs for a UTC S-21 ? TNX DE KA4JVY Mark __ Do You Yahoo!? Yahoo! Health - Feel better, live better http://health.yahoo.com
Re: [AMRadio] Suggestions Please
remember that this xformer is rated at fifty watts, the 12th edition of the RADIO Handbook has a nice 100 watt (max) modulator using pr of 811 Not (A) 1250 volts to do this, also the Z is very high, something like 7500 ohms on the output side. - Original Message - From: <[EMAIL PROTECTED]> To: Sent: Wednesday, July 24, 2002 3:57 PM Subject: Re: [AMRadio] Suggestions Please > > Hello all, > > Related to this thread -- I have several ART-13 mod. transformers: P-P 811s > to 813 final. They don't look like they have a lot of core cross section. > Still, it might be fun to build something up using one. Has anyone had > good results with this mod iron? I don't expect a high powered rig; just > somehting different from my DX-100 or Viking II. I thought I'd build up > the modulator, get that working, then move onto an RF deck. > > Any thoughts? > > Thanks and 73, > > Ed N3CMI > > > ___ > AMRadio mailing list > AMRadio@mailman.qth.net > http://mailman.qth.net/mailman/listinfo/amradio > --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.374 / Virus Database: 209 - Release Date: 07/09/2002
Re: [AMRadio] Suggestions Please
Thanks, Bill! That's good information and the web site is nicely done. I'm getting some ideas now! Next, to find the time... 73, Ed N3CMI
Re: [AMRadio] Suggestions Please
Hi Bill, Thanks for your thoughts. I hadn't considered the possibility of it being a toroid. That would help to explain the size. I'm going to build u pa modulator deck and wee how it works out. Thanks and 73, Ed N3CMI "Bill Smith" <[EMAIL PROTECTED]To: .com> cc: Sent by: Subject: Re: [AMRadio] Suggestions Please [EMAIL PROTECTED] man.qth.net 07/24/02 03:17 PM Please respond to amradio They are supposed to work quite well, and are deceptively small. Probably torroidal. Have some also, but no plans at present. 73 de Bill, AB6MT [EMAIL PROTECTED] - Original Message - From: <[EMAIL PROTECTED]> To: Sent: Wednesday, July 24, 2002 12:57 PM Subject: Re: [AMRadio] Suggestions Please > > Hello all, > > Related to this thread -- I have several ART-13 mod. transformers: P-P 811s > to 813 final. They don't look like they have a lot of core cross section. > Still, it might be fun to build something up using one. Has anyone had > good results with this mod iron? I don't expect a high powered rig; just > somehting different from my DX-100 or Viking II. I thought I'd build up > the modulator, get that working, then move onto an RF deck. > > Any thoughts? > > Thanks and 73, > > Ed N3CMI > > > ___ > AMRadio mailing list > AMRadio@mailman.qth.net > http://mailman.qth.net/mailman/listinfo/amradio ___ AMRadio mailing list AMRadio@mailman.qth.net http://mailman.qth.net/mailman/listinfo/amradio
Re: [AMRadio] Audio response and Long distant QSO's (was: Suggestions Please)
Hi Charlie, I am now living in SW Miss..about 130 miles NE of New Orleans...hope all is well with you..73..Jeff..W0XV..ex W0ONM - Original Message - From: <[EMAIL PROTECTED]> To: Sent: Wednesday, July 24, 2002 8:33 PM Subject: Re: [AMRadio] Audio response and Long distant QSO's (was: Suggestions Please) > > > Jeff: You are too logical!! Wideband for strong signals, narrowband for > weak signals. Almost all AM signals in Nebraska are weak so I > guess that makes me "narrow minded". By the way, there are several > systems that automatically adjust either audio or IF bandwidth > depending upon signal strength (AVC) or signal to noise ratio. > I have used both until DSP came along. Good luck in your discussion. > > 73 DE Charlie, K0NG > > Quoting Jeff Edmonson <[EMAIL PROTECTED]>: > > > > > > > : If you have to ask, then you are probably using too much. If you are > > : listening, you probably aren't using enough. If all you think about is > > : comparing AM to SSB, then you are just looking for a silly argument. > > > > Trust me, Bill, this is not someone "trolling" for a fight in a group. > > > > I'm serious when I ask, though - what's the purpose of trying to run > > audio, starting at 50Hz, on a noisy HF band like 160, 75 or 40m? > > > > honestly, from across the nation, those transmitters who have that much > > low-end response are the same people who want that low-end response > > enhanced, and in periods of QRM/QRN and selective fade, it's more of > > a determent to be able to copy, than an enjoyable, enhanced audio > > performance. I'm absolutely sure that the later is the goal intended, but > > for talking cross-country on noisy bands, SORRY!, it's just not gonna > > happen. > > > > Now, it's possible to have GREAT audio and still filter and tailor the > > audio so that it's not out of the passband, such as that of Don Chester, > > K4KYV. I'm hoping that Don can come in here, and remind me how it is/was > > he was peaking the audio at around 3kc, and then rolling the whole thing > > off at 3.5kc (or slightly higher). And, what's the bottom end? > > > > ___ > > AMRadio mailing list > > AMRadio@mailman.qth.net > > http://mailman.qth.net/mailman/listinfo/amradio > > > > > > ___ > AMRadio mailing list > AMRadio@mailman.qth.net > http://mailman.qth.net/mailman/listinfo/amradio >
Re: [AMRadio] Audio response and Long distant QSO's (was: Suggestions Please)
: : I'm hoping that Don can come in here, and remind me how it is/was : >he was peaking the audio at around 3kc, and then rolling the whole thing : >off at 3.5kc (or slightly higher). And, what's the bottom end? : > : : I do it by using a rising pre-emphasis between curve in the mic preamp, : starting at 800 cps and peaking 8-10 dB at 3 kc/s and above.Also, I use : a D-104 mic (for highs) and a dynamic mic (for lows) mixed together in : phase. The low-pass cutoff is accomplished using passive L-C filters. With : the flip of a switch I can choose between a gradual hf cutoff filter at 5-6 : kc/s, a very sharp cutoff filtor at 3400 cps, or no lowpass filter at all. : The bottom end goes down to 30 cps or so, but the scope shows visible : distortion on a sinewave below about 40 cps. and at those low frequencies, it's rather difficult to hear the bass, anyway. So, would you say that decent (someone define "hi-fi" Ham AM Audio, please) audio could be well received from 50Hz to 4kHz, or less (on the High end)? : With the 3400 cps filter in the circuit, the response curve is flat from 40 : cps to 800 cps, then rises steadily up to about 2 kc/s and begins to : flatten off beyond 3 kc/s, but hits a brick wall at 3400 cps. I bought the : filter at a military surplus store in Washington DC back in 1973 ( I wish I : had purchased half a dozen of them). There is virtually no attenuation at : 3300 cps; at 3400 it is over 25 dB down, and at 3500 cps you can't detect : the signal on the oscilloscope. : The only other filter I have ever seen that has that sharp a cutoff is one : designed by W2WLR that he sent me to evaluate. On the air, when tuned onto your signal, you've got some good, loud CLEAN audio, Don. Your signal isn't as wide as some of the others who are trying to put 10kHz of signal into a 6kHz bandpass. Please, everyone - excuse the comparison, but it does indeed sound a lot like the 'rack audio' SSB guys who are adding pre-emphasis, tone-tailored audio into their SSB rig, AFTER the Balanced modulator, to get a 'wider' spectrum to pass their audio through, taking up sometimes MORE than the conventional AM signal space, and while doing that, complain that "that ol' AM mode takes up too my bandwidth". Just some thinking, while sitting here at 02:18 (insomnia is a bitch!), does anyone think that the rack-audio guys are working on their radios as they are because they hear the AM'ers with decent audio, and are trying to mimick them (of course, without admitting that the AM mode has superior audio -smirk-) or is it because they see that AM is still allowed on the bands, they know damn well how wide an AM signal is, and figure (in their infinite wisdom) that "well, if the AM'ers can do it, than WE CAN TOO!" They just don't remember the AM/SSB wars from years ago. Back then, the fight was over not which MODE was better, but which mode was better for HAM RADIO. The SSB'ers argued that their signal took up 1/3 of the space, of a conventional AM signal. They're right. The AM'ers said that the resulting audio of a SSB signal, at 2.1kHz, was like trying to push an elephant through a keyhole. We were right about that, too. Now, the SSB'ers are using up to 10kHz of audio, AFTER the balanced modulator and when I hear a comment from someone who's fairly connected with Riley and the FCC that says that between Bob Heil and Riley Holingsworth, they're talking about limiting signals to 3kHz (that would be for SSB *only*, I hope!) and I share this informatoin, only to get told "you don't know what you're talking about". Am I the only one that see's the handwriting on the wall? I'm not trying to be a handwringer guys, but hey - something could be happening and party, it might be the blame of the wide-band, "hi-fi" AM audio that 'some' of the AM community runs. Yes run decent audio, yes make air-checks, yes homebrew it all! LIMIT the total bandwidth, so that ALL amatuers can get along on the same band(s). : One thing that is often overlooked is that the audio system capability needs : to extend one octave above and below the intended frequency response of the : program material, to minimise phase distortion effects. This is per : information in the United Transformer Corp. catalogue. For example, if you : intend to transmit high quality voice audio from 100 to 3500 cps, your audio : chain from the mic through the modulator stage needs to be as flat and : distortion free as possible from 50 to 7000 cps. Good "communications" : quality audio 300-3000 cps would require the transmitter to be capable of : 150-6000 cps (that is almost exactly the audio specification of the BC-610). Interesting about the '610... when I fed the output of the Solid State Audio Driver straight to the grids of the 100TH's in the W5MEU "E" model, the difference in audio was (according to others) tremendous, compared to the BC-614 Speech-amp, and that's one that John himself had modified for audio. : Any limiting of frequency r
Re: [AMRadio] Audio response and Long distant QSO's (was: Suggestions Please)
From: "Jeff Edmonson" <[EMAIL PROTECTED]> I'm hoping that Don can come in here, and remind me how it is/was he was peaking the audio at around 3kc, and then rolling the whole thing off at 3.5kc (or slightly higher). And, what's the bottom end? I do it by using a rising pre-emphasis between curve in the mic preamp, starting at 800 cps and peaking 8-10 dB at 3 kc/s and above.Also, I use a D-104 mic (for highs) and a dynamic mic (for lows) mixed together in phase. The low-pass cutoff is accomplished using passive L-C filters. With the flip of a switch I can choose between a gradual hf cutoff filter at 5-6 kc/s, a very sharp cutoff filtor at 3400 cps, or no lowpass filter at all. The bottom end goes down to 30 cps or so, but the scope shows visible distortion on a sinewave below about 40 cps. With the 3400 cps filter in the circuit, the response curve is flat from 40 cps to 800 cps, then rises steadily up to about 2 kc/s and begins to flatten off beyond 3 kc/s, but hits a brick wall at 3400 cps. I bought the filter at a military surplus store in Washington DC back in 1973 ( I wish I had purchased half a dozen of them). There is virtually no attenuation at 3300 cps; at 3400 it is over 25 dB down, and at 3500 cps you can't detect the signal on the oscilloscope. The only other filter I have ever seen that has that sharp a cutoff is one designed by W2WLR that he sent me to evaluate. One thing that is often overlooked is that the audio system capability needs to extend one octave above and below the intended frequency response of the program material, to minimise phase distortion effects. This is per information in the United Transformer Corp. catalogue. For example, if you intend to transmit high quality voice audio from 100 to 3500 cps, your audio chain from the mic through the modulator stage needs to be as flat and distortion free as possible from 50 to 7000 cps. Good "communications" quality audio 300-3000 cps would require the transmitter to be capable of 150-6000 cps (that is almost exactly the audio specification of the BC-610). Any limiting of frequency response should be done using shaping circuitry at low levels, not by limiting response at high levels by using transformers with poor frequency response, or putting capacitors across interstage or modulation transformers, or similar gimmickry often seen in ham rigs. My system seems to work well with my own voice. However, when N3DRB came by for a visit, he operated my station, and everyone told him his voice didn't sound nearly as good as it does on his rig at home. Each operator should make sure the rig is taylored individually to his or her voice. Don K4KYV _ Send and receive Hotmail on your mobile device: http://mobile.msn.com
Re: [AMRadio] Audio response and Long distant QSO's (was: Suggestions Please)
The simple answer is because Amateur Radio is a hobby and because some stations want to sound very good, and the operators work very hard on their station and they do sound very good. PWM has great promise, but why does this design or use of big iron have any factor in this discussion? Why don't you ask the operator about his signal, or if that is too bothersome, why not adjust your receiver so that it will ignore that part of the audio spectrum? - Original Message - From: "Jeff Edmonson" <[EMAIL PROTECTED]> > > Charlie, (and Bill and others) the whole point is, why are some hams trying > to sound better than most broadcast stations? > > If you listen to most broadcast stations, there's some distortion there that > you'd hope you'd never see on your Ham station, but those stations are > TRYING to pass frequencies lower than 50hZ - in fact, they're trying to > pass as low as 30hZ and that requires some BIG iron, UNLESS you're > using PWM/PDM. > > Methinks most mic equalizers could use some tweaking, and some rolling > off of the bass. > > 73 = Best Regards, > -=Jeff/W5OMR=- > > ___ > AMRadio mailing list > AMRadio@mailman.qth.net > http://mailman.qth.net/mailman/listinfo/amradio
Re: [AMRadio] Audio response and Long distant QSO's (was: Suggestions Please)
From: Gary Schafer <[EMAIL PROTECTED]> When you tune off to one side you cut off the other side band and you loose 1/2 of the power. That drops the signal down into the noise on a weak signal. The alleged superiority of SSB over AM is the fact that SSB uses a product detector. With an envelope detector, every component in the passband mixes with every other component. With the product detector, the only mixing action is between the BFO and each component. The result is better readability and less noise in the presence of interference. The Costas synchronous detector solves this problem by allowing you to receive double sideband AM with a product detector. The problem with DSB reception is that the injected carrier from the BFO must be exactly on the same frequency and be EXACTLY IN PHASE with the original carrier, in order for the products of each sideband to reinforce each other. There are several ways to make a sync detector work; most use PLL technology. The "synchronous detectors" on some commercial receivers are not true synchronous detectors because they phase out one sideband and the result is simply SSB reception of an AM signal. The only difference si that it is done by the phasing method rather than with the more common method of using a sharp i.f. filter. With double sideband, you get 6 dB better signal-to-noise ratio than with SSB under identical conditions. First of all, with DSB there is 3 dB more sideband power. With SSB however, you gain 3 dB because the receiver operates at half the bandwidth and thus rejects 3 dB of noise. These effects cancel, so it would seem that there is no advantage to DSB. However, the coherent detection of two sidebands gives twice the voltage output at the detector than what you would get with only one sideband. Twice the voltage = 4 times the power, or 6 dB improvement. Don K4KYV _ MSN Photos is the easiest way to share and print your photos: http://photos.msn.com/support/worldwide.aspx
