Re: FW: [AMRadio] Ranger... good news, bad news
Gary Schafer wrote: The peak envelope power of an AM signal increases by 4 times over the carrier power with 100% modulation. We speak of peak envelop POWER but a scope is actually displaying peak voltage. How do we relate this to 4 times carrier on a scope? The linear amplifier must be tuned at the peak envelope power level or the peaks will never reach full power, the amplifier will flat top and splatter and you will not sound good. I still do not understand. The final is tuned with a tank capacitor and a loading cap. On my amp, the optimal positions of these knobs only change with the frequency is changed. Changing the input level does not effect this tuning in any way that I can see. How much drive power did you have when tuning up the amp? Anywhere from 15 to 80. Were you using a rice box to tune the amp or the ranger? Either... both. If you don't see the scope voltage double with modulation you haven't tuned up right. If you adjust the scope to say 2 centimeters with carrier then the modulation peaks should hit 4 centimeters. Ok... that answers the first question. However, today I changed the rf pickup from a loop on top of the tuner to a wire just running off away from the rig. Bottom line is, that it now looks like 100% modulation. js -- PHOTO OF THE WEEK: http://schmidling.com/pow.htm Astronomy, Beer, Cheese, Fiber,Gems, Sausage,Silver http://schmidling.com __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
Re: [AMRadio] Ranger... good news, bad news
Hi Guys, I haven't really been following this thread all that closely, but has any mention been made yet about the fact that the MAXIMUM amount of RF output carrier that one can safely extract from a linear amplifier tube in AM mode is equal to ONE HALF of the tube's plate dissipation...? Ex. an 813 has 125-watts of plate disipation --- in AM linear amplifier mode, that'd translate to just under 65-watts of AM CARRIER output. I used to run a pair of 813's in AM linear amplifier service for a total of 125-watts carrier output. A 'scope --- like a Heathkit SB-610 --- in trapezoidal mode is absolutely invaluable in setting up an amplifier this way... ~73~ Eddy VE3CUI - VE3XZ - Original Message - From: "Gary Schafer" <[EMAIL PROTECTED]> To: "'Discussion of AM Radio in the Amateur Service'" Sent: Tuesday, November 07, 2006 8:20 PM Subject: FW: [AMRadio] Ranger... good news, bad news > > > -Original Message- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Jack Schmidling > Sent: Thursday, December 07, 2006 5:49 PM > To: Discussion of AM Radio in the Amateur Service > Subject: Re: [AMRadio] Ranger... good news, bad news > > Gary Schafer wrote: > > >If you want to run 125 watts carrier out of the > > SB200 on AM that means you need to tune the amplifier up for 500 watts or > a > > little more output with the load and plate tune controls on the amp peaked > > for maximum output with a given amount of drive. > > Not sure I understand the why of this. I did all as you suggested but > found when I was done that the plate tuning of the amp was exactly the > same as if I tuned it originally with the 100w carrier. The dip was > exactly in the same place and the loading optimum is so broad that no > change could be noted. > > > > Watching the scope on the output of the amplifier should show the > modulation > > peak voltage double what the carrier voltage is on the scope. If it > doesn't > > you haven't tuned up properly. > > Interestingly, the only way I get the peak voltage to double is with the > ricebox. I can never seem to get more than about 50% increase with > modulation. > > js > > The peak envelope power of an AM signal increases by 4 times over the > carrier power with 100% modulation. > The linear amplifier must be tuned at the peak envelope power level or the > peaks will never reach full power, the amplifier will flat top and splatter > and you will not sound good. > > How much drive power did you have when tuning up the amp? > Were you using a rice box to tune the amp or the ranger? > > If you don't see the scope voltage double with modulation you haven't tuned > up right. If you adjust the scope to say 2 centimeters with carrier then the > modulation peaks should hit 4 centimeters. > > 73 > Gary K4FMX > > > > __ > AMRadio mailing list > List Home: http://mailman.qth.net/mailman/listinfo/amradio > Partner Website: http://www.amfone.net > Help: http://mailman.qth.net/mmfaq.html > Post: mailto:AMRadio@mailman.qth.net __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
FW: [AMRadio] Ranger... good news, bad news
-Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Jack Schmidling Sent: Thursday, December 07, 2006 5:49 PM To: Discussion of AM Radio in the Amateur Service Subject: Re: [AMRadio] Ranger... good news, bad news Gary Schafer wrote: >If you want to run 125 watts carrier out of the > SB200 on AM that means you need to tune the amplifier up for 500 watts or a > little more output with the load and plate tune controls on the amp peaked > for maximum output with a given amount of drive. Not sure I understand the why of this. I did all as you suggested but found when I was done that the plate tuning of the amp was exactly the same as if I tuned it originally with the 100w carrier. The dip was exactly in the same place and the loading optimum is so broad that no change could be noted. > Watching the scope on the output of the amplifier should show the modulation > peak voltage double what the carrier voltage is on the scope. If it doesn't > you haven't tuned up properly. Interestingly, the only way I get the peak voltage to double is with the ricebox. I can never seem to get more than about 50% increase with modulation. js The peak envelope power of an AM signal increases by 4 times over the carrier power with 100% modulation. The linear amplifier must be tuned at the peak envelope power level or the peaks will never reach full power, the amplifier will flat top and splatter and you will not sound good. How much drive power did you have when tuning up the amp? Were you using a rice box to tune the amp or the ranger? If you don't see the scope voltage double with modulation you haven't tuned up right. If you adjust the scope to say 2 centimeters with carrier then the modulation peaks should hit 4 centimeters. 73 Gary K4FMX __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
Re: [AMRadio] Ranger... good news, bad news
Gary Schafer wrote: If you want to run 125 watts carrier out of the SB200 on AM that means you need to tune the amplifier up for 500 watts or a little more output with the load and plate tune controls on the amp peaked for maximum output with a given amount of drive. Not sure I understand the why of this. I did all as you suggested but found when I was done that the plate tuning of the amp was exactly the same as if I tuned it originally with the 100w carrier. The dip was exactly in the same place and the loading optimum is so broad that no change could be noted. Watching the scope on the output of the amplifier should show the modulation peak voltage double what the carrier voltage is on the scope. If it doesn't you haven't tuned up properly. Interestingly, the only way I get the peak voltage to double is with the ricebox. I can never seem to get more than about 50% increase with modulation. js -- PHOTO OF THE WEEK: http://schmidling.com/pow.htm Astronomy, Beer, Cheese, Fiber,Gems, Sausage,Silver http://schmidling.com __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
Re: [AMRadio] Ranger... good news, bad news
I tried the accessory plug mod as suggested, removing 2/6 and putting a meter across 2/4 and it works but the power is less than useful. It less than 5 watts and would only modulate about 25%. Did I do something wrong? I put the light bulb back for now. js -- PHOTO OF THE WEEK: http://schmidling.com/pow.htm Astronomy, Beer, Cheese, Fiber,Gems, Sausage,Silver http://schmidling.com __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
RE: [AMRadio] Ranger... good news, bad news
I am not sure that you are really tuning up as you describe but if so you will be flat toping quite seriously. Using a ranger or other AM transmitter with a linear amp requires the amplifier be tuned up with full modulation on the ranger with reduced power out of the ranger watching a scope at the output of the amplifier. It does not have enough carrier at full power to properly drive the SB200 and tune it properly. The easiest/best way to find out how much drive the amplifier needs is to use your rice box first. If you want to run 125 watts carrier out of the SB200 on AM that means you need to tune the amplifier up for 500 watts or a little more output with the load and plate tune controls on the amp peaked for maximum output with a given amount of drive. That drive will be around 80 to 100 watts. Try 80 watts of carrier from the rice box and peak the output of the amp for maximum output. If you can't quite get the 500 watts out increase the drive slightly and re-peak the amplifier tune and load. NOW reduce the drive until you have 125 watts out of the SB200 and MEASURE the drive power required to produce the 125 watts out of the amplifier and DO NOT TOUCH THE TUNING ON THE AMP! The amount of drive that you measured is the amount of carrier you will need from a ranger or other AM rig to drive the amplifier properly. No more no less! If you want to tune up the amp with the ranger driving the amp it needs to be done with full modulation of the ranger and a scope connected to the output of the amplifier. The first thing you need to do is find out how many peak volts on the scope represents 500 watts out of the amplifier. This is done easier with a rice box used as a driver first to establish the 500 watt level on the scope. Once you have that you can connect the ranger as a driver. Tune the amplifier up for maximum peak output, full modulation on the ranger with a tone or voice, watching the scope. Adjust the carrier output of the ranger so that you do not get much over 500 watts peak out of the amplifier. Readjust the tune and load controls on the amplifier for maximum output after each adjustment of the carrier out of the ranger. Always be sure that you are near 100% modulation and not going over on the negative side. Reducing the modulation to zero should yield a carrier right around 125 watts if you tuned everything right. That will allow the modulation peaks to go to 500 watts peak and the amp will be loaded properly. If you don't get 125 watts or near out you haven't tuned up properly. It is very difficult to tune this combination properly as drive is hard to adjust easily. It is much easier to use the rice box first to establish the parameters. Watching the scope on the output of the amplifier should show the modulation peak voltage double what the carrier voltage is on the scope. If it doesn't you haven't tuned up properly. 73 Gary K4FMX > -Original Message- > From: [EMAIL PROTECTED] [mailto:amradio- > [EMAIL PROTECTED] On Behalf Of Peter Markavage > Sent: Monday, November 06, 2006 12:56 PM > To: amradio@mailman.qth.net > Subject: Re: [AMRadio] Ranger... good news, bad news > > I see no reason to "dip and load" the SB-200 since it's a linear > amplifier. When I do use the Ranger as a driver, at low power using my > screen voltage adjustable control, it's initially run into a dummy load > to get the approximate knob settings (dip and load, etc.) for the > frequency of interest. Then it's switched into the input of the SB-200. > SB-200 is tuned for maximum output while viewing an inline wattmeter. If > output power is above 125 watts, I just back down the screen control on > the Ranger and also check and/or adjust plate and load for resonance on > the Ranger(generally minor touching up). You might also want to check > your input circuits on the SB-200. The tuned input on 75M for my SB-200 > was centered around 10 MHz and on 10M, it was centered around 40MHz. > After diddling with the input capacitance values, I was able to get those > bands fairly close to where they should be. Check out the info on this > web site: http://www.ne7x.com/sb200/heathkit-sb200.htm > > With the solid state rigs it's even easier. Push the button for AM, back > down on the RF drive, key down with the SB-200 and quickly tune for max. > On a good day, SB-200 "tune for max" can be done in less than 10 seconds. > > FYI: Scope always hangs on the SB-200 output to watch for any perky RF or > audio anomolies. > > Pete, wa2cwa __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
RE: [AMRadio] Ranger... good news, bad news
That's a good idea Gary. John, WA5BXO -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Gary Schafer Sent: Monday, November 06, 2006 6:56 PM To: 'Discussion of AM Radio in the Amateur Service' Subject: RE: [AMRadio] Ranger... good news, bad news Put a T connector on the output rf connector and put a capacitor on one side of the T. 73 Gary K4FMX __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
RE: [AMRadio] Ranger... good news, bad news
Put a T connector on the output rf connector and put a capacitor on one side of the T. 73 Gary K4FMX > As for my SB200 with a carrier only output of 75 watts the tubes > will show a little color after ten minutes. I would like to drive the > SB200 > harder and unload the output to dip the plate at a lower level but there > is > not enough output capacitance on 75 meters to do this. Perhaps a switched > in extra load capacitor would do the trick? > > Maybe it would be easier to just build a chassis with a pair of > 6146s or 807s running class C with 50 ohm dummy load at the control grid > instead of a tuned circuit and just have the plate circuit tuned. I may > have just talked myself into something!! > > John, WA5BXO __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
Re: [AMRadio] Ranger... good news, bad news
"by removing or cutting off the pins" of an old octal tube base. Healthfully yours, Don W4BWS - Original Message - From: "Jack Schmidling" <[EMAIL PROTECTED]> To: "Discussion of AM Radio in the Amateur Service" Sent: Wednesday, December 06, 2006 2:29 PM Subject: Re: [AMRadio] Ranger... good news, bad news > Donald Sanders wrote: > > You can make a plug from an old octal tube base by removing or cutting off > > the pins and soldering a wire into the pin. > > Maybe I missed something but the socket is nine pins no 8 as in octal. > > js > > -- > PHOTO OF THE WEEK: http://schmidling.com/pow.htm > Astronomy, Beer, Cheese, Fiber,Gems, Sausage,Silver http://schmidling.com > > __ > AMRadio mailing list > List Home: http://mailman.qth.net/mailman/listinfo/amradio > Partner Website: http://www.amfone.net > Help: http://mailman.qth.net/mmfaq.html > Post: mailto:AMRadio@mailman.qth.net > __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
Re: [AMRadio] Ranger... good news, bad news
Only problem is they are 9 pin plugs and not commonly found. I have lots of 8 pin, but no extra 9 pin. Anyone have an abundance, Jack and I both need them. Thanks, Rick/K5IZ Donald Sanders wrote: You can make a plug from an old octal tube base by removing or cutting off the pins and soldering a wire into the pin. Then plug the wire/pin into the back panel socket. You can make a dam from an old cap plug or wax paper and fill the plug with casting plastic, epoxy or RTV. Plugs are available on the e place occasionally or on one of the several BA or equip lists. Healthfully yours, Don W4BWS __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
Re: [AMRadio] Ranger... good news, bad news
Donald Sanders wrote: You can make a plug from an old octal tube base by removing or cutting off the pins and soldering a wire into the pin. Maybe I missed something but the socket is nine pins no 8 as in octal. js -- PHOTO OF THE WEEK: http://schmidling.com/pow.htm Astronomy, Beer, Cheese, Fiber,Gems, Sausage,Silver http://schmidling.com __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
Re: [AMRadio] Ranger... good news, bad news
You can make a plug from an old octal tube base by removing or cutting off the pins and soldering a wire into the pin. Then plug the wire/pin into the back panel socket. You can make a dam from an old cap plug or wax paper and fill the plug with casting plastic, epoxy or RTV. Plugs are available on the e place occasionally or on one of the several BA or equip lists. Healthfully yours, Don W4BWS - Original Message - From: "Jack Schmidling" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]>; "Discussion of AM Radio in the Amateur Service" Sent: Sunday, November 05, 2006 10:48 PM Subject: Re: [AMRadio] Ranger... good news, bad news > Larry Szendrei wrote: > > > Modify the accessory plug as follows (or make a new one if you can find > > a spare): remove the jumper between pins 2&6. External Ip meter (+) > > terminal goes to pin 4; meter (-) terminal to pin 2. The jumper between > > pins 3 & 5 stays as-is. > > > > Almost took as long to describe it as it takes to do it... > > > Love it. Now the problem is, I have no plug and made separate jumper > wires that won't lend themselves to tinkering. > > Does any one have a plug for the Ranger they can part with? > > js > > > -- > PHOTO OF THE WEEK: http://schmidling.com/pow.htm > Astronomy, Beer, Cheese, Fiber,Gems, Sausage,Silver http://schmidling.com > > __ > AMRadio mailing list > List Home: http://mailman.qth.net/mailman/listinfo/amradio > Partner Website: http://www.amfone.net > Help: http://mailman.qth.net/mmfaq.html > Post: mailto:AMRadio@mailman.qth.net > __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
Re: [AMRadio] Ranger... good news, bad news
I see no reason to "dip and load" the SB-200 since it's a linear amplifier. When I do use the Ranger as a driver, at low power using my screen voltage adjustable control, it's initially run into a dummy load to get the approximate knob settings (dip and load, etc.) for the frequency of interest. Then it's switched into the input of the SB-200. SB-200 is tuned for maximum output while viewing an inline wattmeter. If output power is above 125 watts, I just back down the screen control on the Ranger and also check and/or adjust plate and load for resonance on the Ranger(generally minor touching up). You might also want to check your input circuits on the SB-200. The tuned input on 75M for my SB-200 was centered around 10 MHz and on 10M, it was centered around 40MHz. After diddling with the input capacitance values, I was able to get those bands fairly close to where they should be. Check out the info on this web site: http://www.ne7x.com/sb200/heathkit-sb200.htm With the solid state rigs it's even easier. Push the button for AM, back down on the RF drive, key down with the SB-200 and quickly tune for max. On a good day, SB-200 "tune for max" can be done in less than 10 seconds. FYI: Scope always hangs on the SB-200 output to watch for any perky RF or audio anomolies. Pete, wa2cwa On Mon, 6 Nov 2006 10:21:46 -0600 "John E. Coleman (ARS WA5BXO)" <[EMAIL PROTECTED]> writes: > Jack: > There should not be that much difference. Perhaps the > Ranger is not > putting out enough power because of a problem or its output is not > making it > to the antenna. There could be a problem on the pass through > circuitry of > the SB200. Try hooking the Ranger directly to the antenna not > passing it > through the SB200 and don't forget to re-dip the plate on the ranger > after > switching from SB200 to barefoot or vice-versa. Of course if the > SB200 and > ranger combo are putting out 200 - 300 watts then the setup is > wrong. The > output from the Ranger must be reduced until total output from the > SB200 is > about 100 - 125 watts. If you run too much carrier from the SB200 > it will > defiantly over heat and the output will be distorted. Theoretically > the > SB200 is capable of 1000 Watts PEP and theoretically it should be > capable of > 250 watts carrier on AM. But it would be bad news for the SB200 to > do that > for any lengthy time. > > Peter: > As for my SB200 with a carrier only output of 75 watts the > tubes > will show a little color after ten minutes. I would like to drive > the SB200 > harder and unload the output to dip the plate at a lower level but > there is > not enough output capacitance on 75 meters to do this. Perhaps a > switched > in extra load capacitor would do the trick? > > Maybe it would be easier to just build a chassis with a pair > of > 6146s or 807s running class C with 50 ohm dummy load at the control > grid > instead of a tuned circuit and just have the plate circuit tuned. I > may > have just talked myself into something!! > > John, WA5BXO __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
RE: [AMRadio] Ranger... good news, bad news
Jack: There should not be that much difference. Perhaps the Ranger is not putting out enough power because of a problem or its output is not making it to the antenna. There could be a problem on the pass through circuitry of the SB200. Try hooking the Ranger directly to the antenna not passing it through the SB200 and don't forget to re-dip the plate on the ranger after switching from SB200 to barefoot or vice-versa. Of course if the SB200 and ranger combo are putting out 200 - 300 watts then the setup is wrong. The output from the Ranger must be reduced until total output from the SB200 is about 100 - 125 watts. If you run too much carrier from the SB200 it will defiantly over heat and the output will be distorted. Theoretically the SB200 is capable of 1000 Watts PEP and theoretically it should be capable of 250 watts carrier on AM. But it would be bad news for the SB200 to do that for any lengthy time. Peter: As for my SB200 with a carrier only output of 75 watts the tubes will show a little color after ten minutes. I would like to drive the SB200 harder and unload the output to dip the plate at a lower level but there is not enough output capacitance on 75 meters to do this. Perhaps a switched in extra load capacitor would do the trick? Maybe it would be easier to just build a chassis with a pair of 6146s or 807s running class C with 50 ohm dummy load at the control grid instead of a tuned circuit and just have the plate circuit tuned. I may have just talked myself into something!! John, WA5BXO -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Jack Schmidling Sent: Sunday, November 05, 2006 10:09 PM To: Discussion of AM Radio in the Amateur Service Subject: Re: [AMRadio] Ranger... good news, bad news Problem is sig reports go from barely readable to 20 over when I turn on the amp. __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
Re: Re: [AMRadio] Ranger... good news, bad news
I tried that to,it worked great but still too much power for am driving an amp./dale/ka5who - Original Message - From: <[EMAIL PROTECTED]> To: Sent: Sunday, November 05, 2006 11:09 PM Subject: Re: Re: [AMRadio] Ranger... good news, bad news > I am no expert on this issue, but I'd like to run my Ranger II with my 30L-1 linear. What about using a 2E26 in the Ranger II's final instead of the 6146? I have not compared the two tubes specs. > > Regards, > > Robert W4RL Pensacola FL > > > __ > AMRadio mailing list > List Home: http://mailman.qth.net/mailman/listinfo/amradio > Partner Website: http://www.amfone.net > Help: http://mailman.qth.net/mmfaq.html > Post: mailto:AMRadio@mailman.qth.net > __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
Re: [AMRadio] Ranger... good news, bad news
Larry Szendrei wrote: Modify the accessory plug as follows (or make a new one if you can find a spare): remove the jumper between pins 2&6. External Ip meter (+) terminal goes to pin 4; meter (-) terminal to pin 2. The jumper between pins 3 & 5 stays as-is. Almost took as long to describe it as it takes to do it... Love it. Now the problem is, I have no plug and made separate jumper wires that won't lend themselves to tinkering. Does any one have a plug for the Ranger they can part with? js -- PHOTO OF THE WEEK: http://schmidling.com/pow.htm Astronomy, Beer, Cheese, Fiber,Gems, Sausage,Silver http://schmidling.com __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
Re: Re: [AMRadio] Ranger... good news, bad news
I am no expert on this issue, but I'd like to run my Ranger II with my 30L-1 linear. What about using a 2E26 in the Ranger II's final instead of the 6146? I have not compared the two tubes specs. Regards, Robert W4RL Pensacola FL __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
Re: [AMRadio] Ranger... good news, bad news
Jim candela wrote: A SB-200 is good for 100 to 130 watts RF output (carrier only) on AM. This amount on top of a ranger output is way less than 1 S-unit. Problem is sig reports go from barely readable to 20 over when I turn on the amp. >Replace that SB-200 with a SB-220 and the story changes considerably where 350+ watts (carrier) Sad story is that I thought I was buying a 220 but after driving 100 miles to pick it up, it turned into a 200. The power supplies and air cooling methods require you to de-rate the theoretical capabilities of the tubes when running AM. I have a muffin fan on top sucking air out and it seems to help a lot. js -- PHOTO OF THE WEEK: http://schmidling.com/pow.htm Astronomy, Beer, Cheese, Fiber,Gems, Sausage,Silver http://schmidling.com __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
Re: [AMRadio] Ranger... good news, bad news
I've been using the SB-200 on AM since about the mid 90's. Still have the same original tubes that were put in the unit in 1969. I can drive it with the CE100V, 756PRO II, 706MKIIG, Johnson Ranger, and even a Lafayette HA-410(on 10 meters). I've never seen the tubes show any color. I do use, in addition to the internal fan, an external fan as an exhaust on the top of the unit. Output of the SB-200 is generally around 125 watts. I also made the "tuned input" component changes several years ago in my SB-200 as per http://www.ne7x.com/sb200/heathkit-sb200.htm It made a big difference when I run the Ranger and the 100V into the SB-200 on 75 meters. Pete, wa2cwa On Sun, 5 Nov 2006 19:00:26 -0600 "John Coleman ARS WA5BXO" <[EMAIL PROTECTED]> writes: > I was going to comment earlier about the statement that this > Ranger > would not hold it's on against the rice box with the SB200. As Jim > pointed > out there should not be but a DB or so difference if the ranger is > working > properly and properly tuned. I am curious as to what power his > ranger will > put into dummy load and what the modulation looks like. I think I > read in > this thread about someone reducing the drive on the Ranger's grid. > That is > a sure fire way to ruin the output tube (6146). The single 6146 in > class C > service as it is in the Ranger should have 2.5 to 3 milliamps of > drive on it > at all times. Do not reduce the grid current drive to reduce power > on the > Ranger. If memory serves me right the 6146 is to be used at about > 65 watts > plate input on AM plate modulation. It should be putting out between > 40 - 45 > watts carrier and develop about 180 watts PEP. (Could be a little > more with > a good modulation XFMR) That's only about 2-3 DBs below what the > SB200 will > do as an AM linier when operated properly. Now 3 DBs is not to be > taken > lightly when the going is rough but if your going to do a lot of > work for a > DB or 2 then put the work in the antenna or a bigger rig that will > get you > 10 DB gain. > > I have used the SB200 on AM and it does OK but I would not > want to > do it for a long time. Those tubes get real hot. I use the SB200 > as a > driver for my big rig. The input to the SB200 is about 5 - 10 watts > and the > output of the SB200 is about 50 - 70 watts carrier this drives the > grid of > my big class C plate modulated final. But even using the SB200 to > put out > 50 - 70 watts it get real hot and the tube show some color. I think > the > best thing I can do to increase the efficiency of the SB200 at low > power, is > to reduce the plate voltage to about 1500 instead of 2500. I added a > switch > to the front panel of mine to increase the bias voltage making it > harder to > drive. I thought that this would decrease the conduction angle > enough to > reduce the heat but the trouble is that the plate is still not > reaching > saturation at the low power level so I figure that if I reduce the > plate > supply voltage and increase the drive then I can come closer to the > non > linear class C service for continuous CW and the efficiency will > surly > increase. The idea is to use the rice box rig at low power so it > will last > a long time and have the SB200 to make up the slack. But I want it > to last a > long time as well. BJ and I like the flexibility of this type of > operation. > That is to be able to flip some switches and use the SB200 as linier > on SSB > as it was intended and then flip the switches back so as to lower > the output > but raise the efficiency for continuous carrier operation as > required by the > big class C final. We have been operating it linearly with the 2500 > volts > supply and reducing the drive from the rice box carrier source but > it has > always bothered me that it is so inefficient and those tubes show > color. As > I recall the PS in the SB200 is a voltage double type circuit > perhaps a > little circuit change up with some HV switches might be in order > here? > Any Ideas on this? > > > John, WA5BXO > > BTW the stock plate RF choke in the SB200 is NOT large enough on > 75 mtr > and a lot of RF gets back into the PS causing weird AC modulation at > low > carrier levels. BJ and I thought it was the Filter Caps so we got > new ones. > No help. We found that the weird modulation on the output carrier > would > come and go at different levels of drive at low power and only on 75 > mtrs. > We measured the DC at the POWER supply B+ point as it went through > the > chassis to the plate choke and found some RF there and guess what > the RF was > getting back to the diodes in the PS and modulating with the AC. It > was > real weird. Placed a RF choke under the chassis and an extra RF > bypass > cured the whole thing. > > 73, John, WA5BXO > > > > __ > AMRadio mailing list > List Home: http://mailman.qth.net/mail
RE: [AMRadio] Ranger... good news, bad news
John, Are you peaking the output circuit on the SB200 after you reduce the drive? If you are just using carrier out of it to drive the grid of the next amp you should peak everything to get maximum efficiency. Efficiency should be near 60% even at the low power level if you retune the plate circuit. 73 Gary K4FMX > > I have used the SB200 on AM and it does OK but I would not want to > do it for a long time. Those tubes get real hot. I use the SB200 as a > driver for my big rig. The input to the SB200 is about 5 - 10 watts and > the > output of the SB200 is about 50 - 70 watts carrier this drives the grid of > my big class C plate modulated final. But even using the SB200 to put out > 50 - 70 watts it get real hot and the tube show some color. I think the > best thing I can do to increase the efficiency of the SB200 at low power, > is > to reduce the plate voltage to about 1500 instead of 2500. I added a > switch > to the front panel of mine to increase the bias voltage making it harder > to > drive. I thought that this would decrease the conduction angle enough to > reduce the heat but the trouble is that the plate is still not reaching > saturation at the low power level so I figure that if I reduce the plate > supply voltage and increase the drive then I can come closer to the non > linear class C service for continuous CW and the efficiency will surly > increase. The idea is to use the rice box rig at low power so it will > last > a long time and have the SB200 to make up the slack. But I want it to last > a > long time as well. BJ and I like the flexibility of this type of > operation. > That is to be able to flip some switches and use the SB200 as linier on > SSB > as it was intended and then flip the switches back so as to lower the > output > but raise the efficiency for continuous carrier operation as required by > the > big class C final. We have been operating it linearly with the 2500 volts > supply and reducing the drive from the rice box carrier source but it has > always bothered me that it is so inefficient and those tubes show color. > As > I recall the PS in the SB200 is a voltage double type circuit perhaps a > little circuit change up with some HV switches might be in order here? > Any Ideas on this? > > > John, WA5BXO __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
Re: [AMRadio] Ranger... good news, bad news
Jack Schmidling wrote: Most often mis-modification: Reducing output power when driving a linear amplifier through the use of a T connection and a dummy load and/or reducing loading or screen Voltage. This situation wastes one of this rig's better resources namely modulator headroom. When altering the R.F. final's impedance through reduced plate current, the modulation transformer no longer sees the designed load. The correct way to reduce output power is to use an external plate supply with a Variac on the primary or switch the low B+ Voltage to the final (removing the high B+) through the accessory jack. Either way the high B+ is left on the modulators. This gives an immediate improvement to the audio as the modulator requirements are now cut way down without forcing the modulator into an unknown load. With the accessory low power mod, the rig will put out abour 12-14 Watts carrier which is a good level for driving quitea few linear amplifiers. Every available effort to clean up audio distortion should be considered when runnung QRO AM! Whom do I believe? js Believe the above; they speak the truth. While I have no doubt others have used the PA screen voltage and have been satisfied with the results, it is not the best way to go, for the reasons outlined above. Using the low voltage B+ requires no modification except to the accessory plug jumpers; use an external 100mA (optimally) or 200mA full-scale meter for plate current, and you're done. At 300V B+, you'll want to load the plate current to about 60mA. Modify the accessory plug as follows (or make a new one if you can find a spare): remove the jumper between pins 2&6. External Ip meter (+) terminal goes to pin 4; meter (-) terminal to pin 2. The jumper between pins 3 & 5 stays as-is. Almost took as long to describe it as it takes to do it... 73/GL, -Larry/NE1S __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
RE: [AMRadio] Ranger... good news, bad news
I was going to comment earlier about the statement that this Ranger would not hold it's on against the rice box with the SB200. As Jim pointed out there should not be but a DB or so difference if the ranger is working properly and properly tuned. I am curious as to what power his ranger will put into dummy load and what the modulation looks like. I think I read in this thread about someone reducing the drive on the Ranger's grid. That is a sure fire way to ruin the output tube (6146). The single 6146 in class C service as it is in the Ranger should have 2.5 to 3 milliamps of drive on it at all times. Do not reduce the grid current drive to reduce power on the Ranger. If memory serves me right the 6146 is to be used at about 65 watts plate input on AM plate modulation. It should be putting out between 40 - 45 watts carrier and develop about 180 watts PEP. (Could be a little more with a good modulation XFMR) That's only about 2-3 DBs below what the SB200 will do as an AM linier when operated properly. Now 3 DBs is not to be taken lightly when the going is rough but if your going to do a lot of work for a DB or 2 then put the work in the antenna or a bigger rig that will get you 10 DB gain. I have used the SB200 on AM and it does OK but I would not want to do it for a long time. Those tubes get real hot. I use the SB200 as a driver for my big rig. The input to the SB200 is about 5 - 10 watts and the output of the SB200 is about 50 - 70 watts carrier this drives the grid of my big class C plate modulated final. But even using the SB200 to put out 50 - 70 watts it get real hot and the tube show some color. I think the best thing I can do to increase the efficiency of the SB200 at low power, is to reduce the plate voltage to about 1500 instead of 2500. I added a switch to the front panel of mine to increase the bias voltage making it harder to drive. I thought that this would decrease the conduction angle enough to reduce the heat but the trouble is that the plate is still not reaching saturation at the low power level so I figure that if I reduce the plate supply voltage and increase the drive then I can come closer to the non linear class C service for continuous CW and the efficiency will surly increase. The idea is to use the rice box rig at low power so it will last a long time and have the SB200 to make up the slack. But I want it to last a long time as well. BJ and I like the flexibility of this type of operation. That is to be able to flip some switches and use the SB200 as linier on SSB as it was intended and then flip the switches back so as to lower the output but raise the efficiency for continuous carrier operation as required by the big class C final. We have been operating it linearly with the 2500 volts supply and reducing the drive from the rice box carrier source but it has always bothered me that it is so inefficient and those tubes show color. As I recall the PS in the SB200 is a voltage double type circuit perhaps a little circuit change up with some HV switches might be in order here? Any Ideas on this? John, WA5BXO BTW the stock plate RF choke in the SB200 is NOT large enough on 75 mtr and a lot of RF gets back into the PS causing weird AC modulation at low carrier levels. BJ and I thought it was the Filter Caps so we got new ones. No help. We found that the weird modulation on the output carrier would come and go at different levels of drive at low power and only on 75 mtrs. We measured the DC at the POWER supply B+ point as it went through the chassis to the plate choke and found some RF there and guess what the RF was getting back to the diodes in the PS and modulating with the AC. It was real weird. Placed a RF choke under the chassis and an extra RF bypass cured the whole thing. 73, John, WA5BXO __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
RE: [AMRadio] Ranger... good news, bad news
Gary Schafer wrote: > If the tubes glow in an SB200 you are running them too hard. Roger but it is a good reference point. If it just starts to redden after 5 mins, I consider this acceptable and time to shut up anyway. js Reply by Jim C: Actually since linear AM efficiency doubles at 100% tone modulation, the tubes will stay cooler the louder you talk. It's the resting carrier with no modulation that makes the tubes blush the most. The exception is controlled carrier modulation where the drive is cut back in the absence of voice modulation. A SB-200 is good for 100 to 130 watts RF output (carrier only) on AM. This amount on top of a ranger output is way less than 1 S-unit, and overdrive is a big problem. Replace that SB-200 with a SB-220 and the story changes considerably where 350+ watts (carrier) are available with AM. With the SB-200 you have 2 X 160 watts (ICAS) dissipation available whereas with the SB-220 you have 2 X 500 watts (CCS) dissipation available. Figure 30-35% carrier efficiency, and the capabilities of each amplifier are quite different. The power supplies and air cooling methods require you to de-rate the theoretical capabilities of the tubes when running AM. Talking at a high average level (don't splatter) will cool the tubes some, but the power supply don't care if the load current produces power in the form of heat, or additional RF output power during modulation.. I wonder if those out there using Heath linears on AM have anything to add to this? Regards, Jim JKO -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.430 / Virus Database: 268.13.27/517 - Release Date: 11/3/2006 4:30 PM __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
Re: [AMRadio] Ranger... good news, bad news
Gary Schafer wrote: If the tubes glow in an SB200 you are running them too hard. Roger but it is a good reference point. If it just starts to redden after 5 mins, I consider this acceptable and time to shut up anyway. js -- PHOTO OF THE WEEK: http://schmidling.com/pow.htm Astronomy, Beer, Cheese, Fiber,Gems, Sausage,Silver http://schmidling.com __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
Re: [AMRadio] Ranger... good news, bad news
Dale Smith wrote: Hi I just got of the air on 38.70 with my ranger and swan Mark 1 amp two 400zs.Got great audio reports,about 150 watt carrier,using the low voltage = low power mod using the accessory plug,so simple to do .The mod that ne1s spoke about , it works great and the audio quality is suburb, Forget the screen mod and use this one you will not regret it.i can send info if needed. Please do as I do not understand it or am looking at the wrong one. The manual describes something like that but I do not see how it still modulates that way. I also seem to need about 20w to drive the SB200 to max and 10-15 doesn't hack it. js -- PHOTO OF THE WEEK: http://schmidling.com/pow.htm Astronomy, Beer, Cheese, Fiber,Gems, Sausage,Silver http://schmidling.com __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
RE: [AMRadio] Ranger... good news, bad news
> -Original Message- > From: [EMAIL PROTECTED] [mailto:amradio- > [EMAIL PROTECTED] On Behalf Of Jack Schmidling > Sent: Saturday, November 04, 2006 10:04 PM > To: Discussion of AM Radio in the Amateur Service > Subject: Re: [AMRadio] Ranger... good news, bad news > > Mike Sawyer wrote: > > > > > > Now let me ask you a question Jack: Do you intend to use the Ranger > > as a driver for the RF and the audio section as a speech amp for a > > bigger modulator? > > Not at this point. I just want to drive the SB200 and get at least as > much out of it as I do with the TS420 and be able to watch tubes glow. > > js > If the tubes glow in an SB200 you are running them too hard. 73 Gary K4FMX __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
Re: [AMRadio] Ranger... good news, bad news
Hi I just got of the air on 38.70 with my ranger and swan Mark 1 amp two 400zs.Got great audio reports,about 150 watt carrier,using the low voltage = low power mod using the accessory plug,so simple to do .The mod that ne1s spoke about , it works great and the audio quality is suburb, Forget the screen mod and use this one you will not regret it.i can send info if needed. 73/dale/ka5who __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
Re: [AMRadio] Ranger... good news, bad news
Here's where we get into individual preferences and prejudices. I guess I can see where some hams may feel that way about the Ranger, but my prejudice is for high quality audio over communications quality audio. And my opinion is suitable for framing or wrapping fish. Anyway, the Ranger can do a nice job with your SB200 if you're careful and don't try to run more than ~150 watts carrier. Good luck! g Jack Schmidling wrote: ...Interesting as I also was reading a site that claimed the (stock) Ranger has the best audio of any ham rig on the market... __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
Re: [AMRadio] Ranger... good news, bad news
Gary Blau wrote: Yes, the screen mod can be made on its own, as can most of the others. Although it will change the Z the modulator works into it will not have a dramatic effect on audio performance which, quite frankly, already isn't too hot with the stock audio stages and mod xfmr. Interesting as I also was reading a site that claimed the (stock) Ranger has the best audio of any ham rig on the market. The compromise in adjusting the screen is a small one. Try it and see, if you don't like it it's simple enough to take it out. FWIW it worked great for me. Thanks for sorting this out. I will give it a try. js -- PHOTO OF THE WEEK: http://schmidling.com/pow.htm Astronomy, Beer, Cheese, Fiber,Gems, Sausage,Silver http://schmidling.com __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
Re: [AMRadio] Ranger... good news, bad news
Mike Sawyer wrote: Now let me ask you a question Jack: Do you intend to use the Ranger as a driver for the RF and the audio section as a speech amp for a bigger modulator? Not at this point. I just want to drive the SB200 and get at least as much out of it as I do with the TS420 and be able to watch tubes glow. js -- PHOTO OF THE WEEK: http://schmidling.com/pow.htm Astronomy, Beer, Cheese, Fiber,Gems, Sausage,Silver http://schmidling.com __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
Re: [AMRadio] Ranger... good news, bad news
Yes, the screen mod can be made on its own, as can most of the others. Although it will change the Z the modulator works into it will not have a dramatic effect on audio performance which, quite frankly, already isn't too hot with the stock audio stages and mod xfmr. (Hence the more involved audio mods.) I certainly would not lump a screen adjust mod into the same power reducing option basket as a T connection and a dummy load or reducing loading, both of which I would agree are bad (lazy) ideas. The compromise in adjusting the screen is a small one. Try it and see, if you don't like it it's simple enough to take it out. FWIW it worked great for me. If all you want is to reduce the RF to feed a linear then just do the screen mod, or something like it. Many ways to skin this cat. All depends how complex you want to make things. g Jack Schmidling wrote: Guess I missed that "detail". Question though... can that change be made on it's own? Secondly, I found this contrary statement on another site Most often mis-modification: Reducing output power when driving a linear amplifier through the use of a T connection and a dummy load and/or reducing loading or screen Voltage. This situation wastes one of this rig's better resources namely modulator headroom. When altering the R.F. final's impedance through reduced plate current, the modulation transformer no longer sees the designed load. The correct way to reduce output power is to use an external plate supply with a Variac on the primary or switch the low B+ Voltage to the final (removing the high B+) through the accessory jack. Either way the high B+ is left on the modulators. This gives an immediate improvement to the audio as the modulator requirements are now cut way down without forcing the modulator into an unknown load. With the accessory low power mod, the rig will put out abour 12-14 Watts carrier which is a good level for driving quitea few linear amplifiers. Every available effort to clean up audio distortion should be considered when runnung QRO AM! Whom do I believe? js __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
[AMRadio] Ranger... good news, bad news
Now let me ask you a question Jack: Do you intend to use the Ranger as a driver for the RF and the audio section as a speech amp for a bigger modulator? Mod-U-Lator, Mike(y) W3SLK __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
Re: [AMRadio] Ranger... good news, bad news
I guess, buy the issue from ER. For those who may or may not know, here's the complete ER Index from Issue 1 though Issue 207 (Aug. 2006). See what you've missed: http://home.wi.rr.com/n9oo/ersearch.html Nice search features. Pete, wa2cwa On Sat, 04 Nov 2006 17:50:59 -0600 Jack Schmidling <[EMAIL PROTECTED]> writes: > Peter Markavage wrote: > > Adjustment Ranger Output - See Electric Radio Mag, Dec. 2000, page > 25. > > Simple and works very well. > > Easier said than done how does one see that? > > js __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
Re: [AMRadio] Ranger... good news, bad news
Gary Blau wrote: Read it again. The 6146 screen adjust lets you put the RF out anywhere you want from a low of ~8 watts to full tilt. Guess I missed that "detail". Question though... can that change be made on it's own? Secondly, I found this contrary statement on another site Most often mis-modification: Reducing output power when driving a linear amplifier through the use of a T connection and a dummy load and/or reducing loading or screen Voltage. This situation wastes one of this rig's better resources namely modulator headroom. When altering the R.F. final's impedance through reduced plate current, the modulation transformer no longer sees the designed load. The correct way to reduce output power is to use an external plate supply with a Variac on the primary or switch the low B+ Voltage to the final (removing the high B+) through the accessory jack. Either way the high B+ is left on the modulators. This gives an immediate improvement to the audio as the modulator requirements are now cut way down without forcing the modulator into an unknown load. With the accessory low power mod, the rig will put out abour 12-14 Watts carrier which is a good level for driving quitea few linear amplifiers. Every available effort to clean up audio distortion should be considered when runnung QRO AM! Whom do I believe? js -- PHOTO OF THE WEEK: http://schmidling.com/pow.htm Astronomy, Beer, Cheese, Fiber,Gems, Sausage,Silver http://schmidling.com __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
Re: [AMRadio] Ranger... good news, bad news
Peter Markavage wrote: Adjustment Ranger Output - See Electric Radio Mag, Dec. 2000, page 25. Simple and works very well. Easier said than done how does one see that? js -- PHOTO OF THE WEEK: http://schmidling.com/pow.htm Astronomy, Beer, Cheese, Fiber,Gems, Sausage,Silver http://schmidling.com __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
Re: [AMRadio] Ranger... good news, bad news
Read it again. The 6146 screen adjust lets you put the RF out anywhere you want from a low of ~8 watts to full tilt. g Jack Schmidling wrote: Gary Blau wrote: Here's just one example: http://www.w3am.com/ranger.html That one is just the opposite of what I want to do. It increases power output. js __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
Re: [AMRadio] Ranger... good news, bad news
Adjustment Ranger Output - See Electric Radio Mag, Dec. 2000, page 25. Simple and works very well. Pete, wa2cwa On Sat, 04 Nov 2006 11:49:46 -0600 Jack Schmidling <[EMAIL PROTECTED]> writes: > Gary Blau wrote: > > Here's just one example: > > http://www.w3am.com/ranger.html > > That one is just the opposite of what I want to do. It increases > power > output. > > js > __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
Re: [AMRadio] Ranger... good news, bad news
Gary Blau wrote: Here's just one example: http://www.w3am.com/ranger.html That one is just the opposite of what I want to do. It increases power output. js -- PHOTO OF THE WEEK: http://schmidling.com/pow.htm Astronomy, Beer, Cheese, Fiber,Gems, Sausage,Silver http://schmidling.com __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
Re: [AMRadio] Ranger... good news, bad news
If you are considering high level modulation on the 6146's you might want to change the screen resistor to... generally speaking commercial ham units use screen resistors to small in value for proper modulation characteristics... Check it out for yourself... dig out a tube manual and plug the values into the formulas and you get a much better screen resistor value... Just a thought... But Larry is right... use the lower values in the way he mentioned... The screen resistor??? I might have got that from Timtron too many years ago... ??? 73 vince [EMAIL PROTECTED] This is the Timtron-approved way of doing it, and I can vouch for it, as it has worked well for me. 73/GL, -Larry/NE1S __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
Re: [AMRadio] Ranger... good news, bad news
Here's just one example: http://www.w3am.com/ranger.html g Brian Carling wrote: Larry and Jack, there is an article on how to do just that on the web somewhere. As the others have said, it is the best way to reduce your drive to the RF final. From: Peter Markavage <[EMAIL PROTECTED]> Why not just make the screen voltage adjustable by using either a variable pot or some solid-state circuitry with a variable pot __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
Re: [AMRadio] Ranger... good news, bad news
Larry and Jack, there is an article on how to do just that on the web somewhere. As the others have said, it is the best way to reduce your drive to the RF final. From: Peter Markavage <[EMAIL PROTECTED]> > Why not just make the screen voltage adjustable by using either a > variable pot or some solid-state circuitry with a variable pot __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
Re: [AMRadio] Ranger... good news, bad news
Why not just make the screen voltage adjustable by using either a variable pot or some solid-state circuitry with a variable pot. Pot can be mounted behind the xtal socket with a small knob or shaft protruding through the center hole of the xtal socket. Electric Radio, not to long ago, had a simple circuit for this that worked very well. And the plate current meter still worked and no diddling behind the Ranger with the accessory socket. Pete, wa2cwa On Fri, 03 Nov 2006 21:02:54 -0500 Larry Szendrei <[EMAIL PROTECTED]> writes: > Jack Schmidling wrote: > > I have read page after page of mods and changes to the Ranger to > make it > > suitable to drive an am and wonder why I can't just reduce the > drive to > > get about 15 watts out and be done with it. > > > > What am I missing? > > > > js > > > > The problem is that in a Class C amplifier the grid is driven well > beyond "saturation" (no additional power output with increasing > drive). > If this wasn't the case, you would have no increase in output with > increasing plate voltage on positive modulation peaks - so there > would > be no positive peaks in your "AM" RF output! Also, reducing drive > will > reduce your plate efficiency greatly and you may exceed your plate > dissipation in the 6146 PA tube (in case you wanted to try this for > CW). > > IMHO the best way to reduce the output from a Ranger to drive an amp > is > to use the LV power supply (~300V) for the PA plate supply instead > of > the HV plate supply. This can be done right at the accessory plug in > > back of the rig, but you'll lose your plate current indication on > the > panel meter. You can either rewire the Ranger internally so that it > will > read Ip no matter whether you use the LV or HV plate supply (as I > have > on mine), or use an external plate current meter wired to the > accessory > plug. Of you choose the latter you can leave the Ranger stock and > not > even take it out of the cabinet! > > You can still use the HV supply on the modulator plates for lots of > > audio headroom, but turn the audio gain pot will be way down from > where > it is when running the rig at full output. > > With this approach you'll get about 12-15W out, perfect for driving > a > linear amp. > > This is the Timtron-approved way of doing it, and I can vouch for > it, as > it has worked well for me. > > 73/GL, > -Larry/NE1S __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
Re: [AMRadio] Ranger... good news, bad news
Jack Schmidling wrote: I have read page after page of mods and changes to the Ranger to make it suitable to drive an am and wonder why I can't just reduce the drive to get about 15 watts out and be done with it. What am I missing? js The problem is that in a Class C amplifier the grid is driven well beyond "saturation" (no additional power output with increasing drive). If this wasn't the case, you would have no increase in output with increasing plate voltage on positive modulation peaks - so there would be no positive peaks in your "AM" RF output! Also, reducing drive will reduce your plate efficiency greatly and you may exceed your plate dissipation in the 6146 PA tube (in case you wanted to try this for CW). IMHO the best way to reduce the output from a Ranger to drive an amp is to use the LV power supply (~300V) for the PA plate supply instead of the HV plate supply. This can be done right at the accessory plug in back of the rig, but you'll lose your plate current indication on the panel meter. You can either rewire the Ranger internally so that it will read Ip no matter whether you use the LV or HV plate supply (as I have on mine), or use an external plate current meter wired to the accessory plug. Of you choose the latter you can leave the Ranger stock and not even take it out of the cabinet! You can still use the HV supply on the modulator plates for lots of audio headroom, but turn the audio gain pot will be way down from where it is when running the rig at full output. With this approach you'll get about 12-15W out, perfect for driving a linear amp. This is the Timtron-approved way of doing it, and I can vouch for it, as it has worked well for me. 73/GL, -Larry/NE1S __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
[AMRadio] Ranger... good news, bad news
Thanks to the help of Rick Brasher and others on this list and three weeks with the longnose and soldering iron, I fired up the Ranger and got standing ovations this morning and on the Noon Net. The Noon Net, BTW, was a smashing success with 6 checkins including N900 from this list. The bad news is, after it was over I was informed that several ops had problems hearing me. I then fired up the TS430 and SB200 and got loud and clear from these ops. So, after all this work, I have a working Ranger that seems to need some help. I also have a working T60 that I was using with the amp while working on the Ranger. With that as background, I seem to have two options if I want to stick with tubes: 1. Boost the power of the T60 to get all I can out of the amp. 2. Reduce the power of the Ranger for the same purpose. The latter seems (intuitively) the obvious and simpler option. However, I have read page after page of mods and changes to the Ranger to make it suitable to drive an am and wonder why I can't just reduce the drive to get about 15 watts out and be done with it. What am I missing? js -- PHOTO OF THE WEEK: http://schmidling.com/pow.htm Astronomy, Beer, Cheese, Fiber,Gems, Sausage,Silver http://schmidling.com __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
