[AMRadio] Shorting stick
I always thought you had to discharge though a high value resistance to avoid damaging arcs that would hurt the surface you were discharging through a plasma arc. I do remember using a shorting stick in a job I had 20 years ago. Alan
[AMRadio] DX-60 mode switch
I find the DX-60 mode switch to be a bit odd, I counted the actual steps from off to CW. There were 8 steps. Does this mean it was an original 8 position, or is my switch going bad? When put in the right positions it seems FB. 73 Alan VY2WU
[AMRadio] DX-60 mode switch
Does anyone have a replacement mode switch for a DX-60. I am beginning to worry about mine. 73 Alan VY2WU
[AMRadio] D104 mic element testing
OK, how do you test a D104 mic element to see if is bad? Resistance? Check with an oscillosope? I dunno. Alan
RE: [AMRadio] HR-10 problem
Have you made any mods to the DX-60? BTW, it makes a great CW pair. I have a realistic DSP filter coming to help out with CW. 73 Alan Quoting Brian Carling <[EMAIL PROTECTED]>: > Let us know how it works. > I use an HR10B here also and mine doesn't do that. > > I am ready on the air with the DX60-HR10 combo. > > Brian, AF4K > > > I am sure I can find it. > > > > Best 73 > > Alan > > > > > > > > Quoting W1EOF <[EMAIL PROTECTED]>: > > > > > My HR-10B doesn't do it Alan, so it's not inherent in the design. As > Brett > > > suggested, look for voltages that are out of spec. > > > > > > 73, > > > > > > Mark W1EOF > > > > > > > -Original Message- > > > > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] > > > > Sent: Monday, April 10, 2006 9:49 AM > > > > To: AMRadio@mailman.qth.net > > > > Subject: [AMRadio] HR-10 problem > > > > > > > > > > > > Hi, > > > > > > > > I am running an HR-10 RX in my shack outside and am wondering how > > > > to cure an > > > > annoying fault. Or, this may be bad design, but I don't remember > > > > this from when > > > > I was a kid. > > > > > > > > When i turn up the RF Gain, and end up close to full on it, I get > > > > a shift down > > > > in frequency of the CW note. So far that I have to retune the BFO > > > > to get it > > > > back. > > > > > > > > The RF Gain is in series with the Cathode of the first RF stage of the > RX. > > > > > > > > perhaps a Zener diode to cure it? > > > > > > > > And if so, I guess I should measure the voltage someplace and > > > > clamp with a > > > > zener, but then again, I would be modifying the whole circut. > > > > > > > > Anyone know how to fix this? > > > > > > > > Best 73, > > > > > > > > Alan > > > > __ > > > > AMRadio mailing list > > > > Home: http://mailman.qth.net/mailman/listinfo/amradio > > > > Help: http://mailman.qth.net/mmfaq.html > > > > Post: mailto:AMRadio@mailman.qth.net > > > > AMfone Website: http://www.amfone.net > > > > AM List Admin: Brian Sherrod/w5ami, Paul Courson/wa3vjb > > > > > > > > > > > > -- > > > > No virus found in this incoming message. > > > > Checked by AVG Free Edition. > > > > Version: 7.1.385 / Virus Database: 268.4.0/306 - Release Date: 4/9/06 > > > > > > > -- > > > No virus found in this outgoing message. > > > Checked by AVG Free Edition. > > > Version: 7.1.385 / Virus Database: 268.4.0/306 - Release Date: 4/9/06 > > > > > > __ > > > AMRadio mailing list > > > Home: http://mailman.qth.net/mailman/listinfo/amradio > > > Help: http://mailman.qth.net/mmfaq.html > > > Post: mailto:AMRadio@mailman.qth.net > > > AMfone Website: http://www.amfone.net > > > AM List Admin: Brian Sherrod/w5ami, Paul Courson/wa3vjb > > > > > > > > > > > __ > > AMRadio mailing list > > Home: http://mailman.qth.net/mailman/listinfo/amradio > > Help: http://mailman.qth.net/mmfaq.html > > Post: mailto:AMRadio@mailman.qth.net > > AMfone Website: http://www.amfone.net > > AM List Admin: Brian Sherrod/w5ami, Paul Courson/wa3vjb > > > > > __ > AMRadio mailing list > Home: http://mailman.qth.net/mailman/listinfo/amradio > Help: http://mailman.qth.net/mmfaq.html > Post: mailto:AMRadio@mailman.qth.net > AMfone Website: http://www.amfone.net > AM List Admin: Brian Sherrod/w5ami, Paul Courson/wa3vjb >
RE: [AMRadio] HR-10 problem
I am sure I can find it. Best 73 Alan Quoting W1EOF <[EMAIL PROTECTED]>: > My HR-10B doesn't do it Alan, so it's not inherent in the design. As Brett > suggested, look for voltages that are out of spec. > > 73, > > Mark W1EOF > > > -Original Message- > > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] > > Sent: Monday, April 10, 2006 9:49 AM > > To: AMRadio@mailman.qth.net > > Subject: [AMRadio] HR-10 problem > > > > > > Hi, > > > > I am running an HR-10 RX in my shack outside and am wondering how > > to cure an > > annoying fault. Or, this may be bad design, but I don't remember > > this from when > > I was a kid. > > > > When i turn up the RF Gain, and end up close to full on it, I get > > a shift down > > in frequency of the CW note. So far that I have to retune the BFO > > to get it > > back. > > > > The RF Gain is in series with the Cathode of the first RF stage of the RX. > > > > perhaps a Zener diode to cure it? > > > > And if so, I guess I should measure the voltage someplace and > > clamp with a > > zener, but then again, I would be modifying the whole circut. > > > > Anyone know how to fix this? > > > > Best 73, > > > > Alan > > __ > > AMRadio mailing list > > Home: http://mailman.qth.net/mailman/listinfo/amradio > > Help: http://mailman.qth.net/mmfaq.html > > Post: mailto:AMRadio@mailman.qth.net > > AMfone Website: http://www.amfone.net > > AM List Admin: Brian Sherrod/w5ami, Paul Courson/wa3vjb > > > > > > -- > > No virus found in this incoming message. > > Checked by AVG Free Edition. > > Version: 7.1.385 / Virus Database: 268.4.0/306 - Release Date: 4/9/06 > > > -- > No virus found in this outgoing message. > Checked by AVG Free Edition. > Version: 7.1.385 / Virus Database: 268.4.0/306 - Release Date: 4/9/06 > > __ > AMRadio mailing list > Home: http://mailman.qth.net/mailman/listinfo/amradio > Help: http://mailman.qth.net/mmfaq.html > Post: mailto:AMRadio@mailman.qth.net > AMfone Website: http://www.amfone.net > AM List Admin: Brian Sherrod/w5ami, Paul Courson/wa3vjb >
RE: [AMRadio] HR-10 problem
You are right, I should be searhing around for some voltage out of spec. 73, Alan Quoting Brett gazdzinski <[EMAIL PROTECTED]>: > Maybe the tube is out of bias, to much screen voltage, > or some resistor has changed value and the LO tube > voltage is varying around? > Maybe check things with the DMM? > > Or maybe the bfo is changing, not the LO?? > > Brett > N2DTS > > > -Original Message- > > From: [EMAIL PROTECTED] > > [mailto:[EMAIL PROTECTED] On Behalf Of > > [EMAIL PROTECTED] > > Sent: Monday, April 10, 2006 9:49 AM > > To: AMRadio@mailman.qth.net > > Subject: [AMRadio] HR-10 problem > > > > Hi, > > > > I am running an HR-10 RX in my shack outside and am wondering > > how to cure an > > annoying fault. Or, this may be bad design, but I don't > > remember this from when > > I was a kid. > > > > When i turn up the RF Gain, and end up close to full on it, I > > get a shift down > > in frequency of the CW note. So far that I have to retune the > > BFO to get it > > back. > > > > The RF Gain is in series with the Cathode of the first RF > > stage of the RX. > > > > perhaps a Zener diode to cure it? > > > > And if so, I guess I should measure the voltage someplace and > > clamp with a > > zener, but then again, I would be modifying the whole circut. > > > > Anyone know how to fix this? > > > > Best 73, > > > > Alan > > __ > > AMRadio mailing list > > Home: http://mailman.qth.net/mailman/listinfo/amradio > > Help: http://mailman.qth.net/mmfaq.html > > Post: mailto:AMRadio@mailman.qth.net > > AMfone Website: http://www.amfone.net > > AM List Admin: Brian Sherrod/w5ami, Paul Courson/wa3vjb > > > > __ > AMRadio mailing list > Home: http://mailman.qth.net/mailman/listinfo/amradio > Help: http://mailman.qth.net/mmfaq.html > Post: mailto:AMRadio@mailman.qth.net > AMfone Website: http://www.amfone.net > AM List Admin: Brian Sherrod/w5ami, Paul Courson/wa3vjb >
[AMRadio] HR-10 problem
Hi, I am running an HR-10 RX in my shack outside and am wondering how to cure an annoying fault. Or, this may be bad design, but I don't remember this from when I was a kid. When i turn up the RF Gain, and end up close to full on it, I get a shift down in frequency of the CW note. So far that I have to retune the BFO to get it back. The RF Gain is in series with the Cathode of the first RF stage of the RX. perhaps a Zener diode to cure it? And if so, I guess I should measure the voltage someplace and clamp with a zener, but then again, I would be modifying the whole circut. Anyone know how to fix this? Best 73, Alan
[AMRadio] possible interference coming up
Hi gang, I have a neighbour about 150 feet away from the end of my dipole, not broadside. He is not currently active with his electric guitars, but soon will be. He has all sorts of foot pedals wired in series to a couple of amplifiers at each end of his music room. I feel it is interference waiting to happen. Does anyone have any experience with this? Am I to expect to QRM him? 73, Alan
Re: [AMRadio] Cable
Electrosonic in Canada 1-800-56SONIC Or you can call any of the Broadcasters who may use it in wiring thier studioes. 73 Alan Quoting Rick Brashear <[EMAIL PROTECTED]>: > Does anyone have a good source for 8 conductor shielded cable as used to > connect the BC-614 speech amplifier to the BC-610 transmitter? I'm sure > the regular sources will have it, but I am curious if anyone has a more > reasonably priced outlet. I am in need of about 20'. > > Thanks, > Rick/K5IZ > > > __ > AMRadio mailing list > Home: http://mailman.qth.net/mailman/listinfo/amradio > Help: http://mailman.qth.net/mmfaq.html > Post: mailto:AMRadio@mailman.qth.net > AMfone Website: http://www.amfone.net > AM List Admin: Brian Sherrod/w5ami, Paul Courson/wa3vjb >
RE: [AMRadio] Use of an oscilloscope to monitor am audio
I just got a 1963 handbook and I am proud to have it. I was two years old when it was printed. 73 Alan Quoting "Craig C. Heaton" <[EMAIL PROTECTED]>: > Good Morning Jim, > > Yup, some addional hardware is needed for both a waveform and trapezoidal > pattern. Best to get an older ARRL(g) Handbook from the late 1950's > early 1960's. The circuits and hardware are descriped there. > > I can send info, .pdf file, jpegs, and parts list of a little box I built > for my cheap $5 hamfest Eico 460. > > 73's > wd8kdg > Craig > > -Original Message- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] Behalf Of Jim Miller WB5OXQ > Sent: Saturday, March 18, 2006 9:29 AM > To: Discussion of AM Radio > Subject: [AMRadio] Use of an oscilloscope to monitor am audio > > > I have a Tektronix model 453a scope and I would like to know how it can be > used to monitor transmitted signals. Do I need extra hardware or an > interface of some type to obtain the trapezoid pattern? I know some scopes > designed for amateur radio have this feature built in so I wonder if my > scope can be used for this? > WB5OXQ. > > > __ > AMRadio mailing list > Home: http://mailman.qth.net/mailman/listinfo/amradio > Help: http://mailman.qth.net/mmfaq.html > Post: mailto:AMRadio@mailman.qth.net > AMfone Website: http://www.amfone.net > AM List Admin: Brian Sherrod/w5ami, Paul Courson/wa3vjb > > > __ > AMRadio mailing list > Home: http://mailman.qth.net/mailman/listinfo/amradio > Help: http://mailman.qth.net/mmfaq.html > Post: mailto:AMRadio@mailman.qth.net > AMfone Website: http://www.amfone.net > AM List Admin: Brian Sherrod/w5ami, Paul Courson/wa3vjb >
[AMRadio] use of scope to monitor output audio
How does a high vswr affect the modulated envelope on an AM TX? I would expect a decrease of forward power to decrease the envelope and distort the signal somehow. Perhaps suppressing the audio? Alan
RE: [AMRadio] Amplifier to use with my DX-60
Thanks so much for taking the time to remind me about all this stuff!!! When I was 25 I worked on a Gates 50B that was as old as I was. I mostly just monitored voltages and looked for trouble. I was facsinated back then as I find myself being now while I foray into the world of AM again. I spent too much time in Broadcast as a studio tech. Cheers, Alan VY2WU Quoting Donald Chester <[EMAIL PROTECTED]>: > > > > >From: Alan Beck <[EMAIL PROTECTED]> > > >I would like to use a cheap am with my DX-60. > > > >An SB-200-230 seems to be a Class B amp. There for it only conducts on the > >positive going cycle. I don't mean to sound silly, but someone told me I > >could run this in SSB Mode using AM input from my DX-60, I run 100 Watts > >carrier for 400 Watts peak, now that makes sense. > > > >What does not make sense is how do I get the other side of the wave > >form The Tank??? I guess the tank. > > > > The linear will work on AM as long as you don't exceed the peak power output > > rating. Exceeding the peak output rating will cause the signal to flat-top, > > distort and splatter. > > Another thing to watch for is the plate dissipation of the tubes. If I > recall correctly, the SB-200 series uses a pair of 3-500Z tubes in the > final. That means you have 1000 watts of plate dissipation available. > Running AM linear @ 100% modulation will give carrier output efficiency of > about 30%. So you could run maximum 1500 watts DC input to those tubes, > with 500 watts carrier output, and 1000 watts dissipated by the tubes. With > > modulation, the tubes will actually cool down slightly, since the DC input > will not vary, but the amplifier will deliver sideband power in addition to > carrier power output. So some of the input power will be converted to rf in > > the sidebands instead of heat in the tube plates. > > But you also have to be careful with the power supply. AM runs at 100% duty > > cycle, so the power supply in the amplifier may not be rated to run 1500 > watts continuous duty. After a few minutes, the power transformer may > overheat. In that case you will have to run it at reduced power. But be > careful that the plate efficiency does not exceed about 33%. If you run it > at too high plate efficiency, it will not leave you enough headroom to > accomodate the positive peaks, and flat-topping/distortion/splatter will > result. > > Don't worry about the missing half of the rf cycle. It works with AM > exactly the same way as it does with SSB. Since the amplifier is single > ended and not pushpull, the missing half of the rf cycle is filled in by the > > "flywheel effect" of the rf tank circuit. > > In summary, with class-B linear AM operation, the final will run about 33% > carrier efficiency. The peak efficiency on modulation peaks will be about > double that, 67%. Two-thirds of the DC input to the final will be > dissipated as heat in the plates of the tubes under carrier-only, no > modulation conditions. That means the carrier output will be one half the > plate dissipation of the tubes. The peak power output should be about 4 > times the resting carrier output at 100% modulation, if flat-topping is to > be avoided. > > Linear amplifier AM operation dates back to the very earliest days of radio. > > The earliest high power broadcast stations used it. It was used for years > > before anyone figured out how to run audio amplifiers in class-B. Before > then, the only kind of high level plate modulation that was used employed > class A audio amplifiers, usually the "Heising" circuit but sometimes series > > modulation was used. Both those systems ran at lower ovarall efficiency > than linear rf amplification. Therefore, AM linears were used long before > high level plate modulation for high powered AM transmitters. > _ > > This message was typed using the DVORAK keyboard layout. Try it - you'll > like it. > http://www.mwbrooks.com/dvorak/ > http://gigliwood.com/abcd/ > > > __ > AMRadio mailing list > Home: http://mailman.qth.net/mailman/listinfo/amradio > Help: http://mailman.qth.net/mmfaq.html > Post: mailto:AMRadio@mailman.qth.net > AMfone Website: http://www.amfone.net > AM List Admin: Brian Sherrod/w5ami, Paul Courson/wa3vjb >
