Re: [AMRadio] Screen Modulated 813
From: Jack Schmidling [EMAIL PROTECTED] That's about how my SB200 runs. If I run much over 100w, it gets to red for my comfort. I never stop talking so I guess I am at it's peak. Actually, it should cool down a little when you talk. Maximum plate dissipation is under unmodulated carrier conditions. The DC input to the final should remain unchanged regardless of modulation. So the additional output power in the sidebands, at constant DC input, means that the efficiency becomes higher as the carrier is modulated, and the plates should cool down a bit. Don k4kyv ___ This message was typed using the DVORAK keyboard layout. http://www.mwbrooks.com/dvorak/ http://gigliwood.com/abcd/ __ 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] RF Amp
Rick, If you have the parts on hand, it's a shame not to use them in something. I always thought it was odd that some people collect huge amounts of parts, but never do anything with them. I am the other way around, if I have nice parts, they scream at me to be used. A tube or transformer is a terrible thing to waste. I been working on the 811 modulator for the pair of 4D32's. Its almost done, and its time to think about what to build next... Brett N2DTS Brett, I agree and you're correct on all counts. However, I have the iron just sitting in the shed and the thought of those two 450TL's and two 250TH's glowing through a glass window is more than my being practical can overcome. I have accumulated many high voltage/current capacitors for both the power supply and the RF stage. Granted, it is a tremendous over kill, but it should be able to loaf along at legal limit. Naturally, I wouldn't want to exceed the legal limit. I'm sure I would stand out like a sore thumb if I were to do that. :-D I also agree that all push pull triode amplifiers are basically the same. I was just hoping to hear from someone who had used that particular configuration and see what their results were. Thanks for the info... Rick/K5IZ Brett gazdzinski wrote: I think the 405 TL's will require a LOT if filament power, that's for sure! I also think they like very high voltages, over 3000, which will make things tend to be huge... If you get it built, we are going to monitor you closely, and if you go over 1501 watts pep, you will be in big trouble Besides the power and voltage, all push pull triode setups are the same. You can take any push pull rf deck and just scale it up Brett N2DTS __ 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] Antenna's..
Craig, Thanks for the info. What power do you run? I might be able to get 110 feet, maybe a little more if I put the wire in the tree branches...insulated wire? I have found that the RG214 coax can get real hot if I run into an antenna that is not resonant... I have the heath 2060a, although I hate to use it. Brett N2DTS -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Craig Carter Sent: Friday, December 08, 2006 11:33 PM To: Discussion of AM Radio in the Amateur Service Subject: RE: Re: [AMRadio] Antenna's.. I had one of the Alpha Delta 40 80 and a multi band Alpha Delta dipoles. With a tuner, the multi band was one of the best dummy loads I've ever had. The 80 / 40 trapless dipole was 'eh' on 80, ok on 40. I now have a 125' dipole, bent all over he!! and gone, and a Heath SA 2060 tuner with RG 8. Works great on every band I try it on, including 6 and 2! I would put up the longest wire I could fit, get a BAT (big 'butted' tuner) and have fun. 73 Craig K6QI __ 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] Lettering or decals for BC 610
I like a P touch using clear tape with white letters. You can print out whole words or multi words, in many different fonts and sizes, and just stick it on. You can trim the tape so its no bigger then the letters... I used to use daytak dry transfers then clear coat, but they got old and would not stick anymore. I eliminate the clear coat, and can peel off the P touch labels if I need to I also use it to label the chassis, on things like connections, tube sockets, etc. Brett N2DTS -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Bill Fondren Sent: Sunday, December 10, 2006 8:49 AM To: amradio@mailman.qth.net Subject: [AMRadio] Lettering or decals for BC 610 I think I sent this question to the wrong email addressNo telling where it went Anyway I will send it again. I just got an old BC 610 on the air. I need to paint the unit No problem with painting it, but what is the best way to get the lettering or decals on the front panel. I went to our local sign shop and the lady warned me that the computer cut letters that small would not be to good. She tried and she was correct. She said she could have the letters printed on a clear stickon sheet, something like stotch tape I guess. Has anyone tried any of the decal kits available on the internet. Found some kits that are called water slide decals, but white letters take a special kit. Hope some one out there has a good solution Bill K5PML __ 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] Lettering or decal for BC 610
What is P touch, Never heard of that , I know of dry labels -- KC7HKP George Yazzolino 14801 NE 20th Circle Vancouver, Wa. 98684 Grid CN-85 [EMAIL PROTECTED] -- Original message -- From: Brett gazdzinski [EMAIL PROTECTED] I like a P touch using clear tape with white letters. You can print out whole words or multi words, in many different fonts and sizes, and just stick it on. You can trim the tape so its no bigger then the letters... I used to use daytak dry transfers then clear coat, but they got old and would not stick anymore. I eliminate the clear coat, and can peel off the P touch labels if I need to I also use it to label the chassis, on things like connections, tube sockets, etc. Brett N2DTS -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Bill Fondren Sent: Sunday, December 10, 2006 8:49 AM To: amradio@mailman.qth.net Subject: [AMRadio] Lettering or decals for BC 610 I think I sent this question to the wrong email address No telling where it went Anyway I will send it again. I just got an old BC 610 on the air. I need to paint the unit No problem with painting it, but what is the best way to get the lettering or decals on the front panel. I went to our local sign shop and the lady warned me that the computer cut letters that small would not be to good. She tried and she was correct. She said she could have the letters printed on a clear stickon sheet, something like stotch tape I guess. Has anyone tried any of the decal kits available on the internet. Found some kits that are called water slide decals, but white letters take a special kit. Hope some one out there has a good solution Bill K5PML __ 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 __ 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] BANDWARMING PARTY Dec. 15th
In case you don't regularly visit eham.net or QRZ.com, I have penned a brief news article about this coming Friday that I hope you can pass along to anyone who can take part with us. When passing along as a forwarded message, kindly remove my email address so I can minimize unintentional repetition and the possibility of spam. Vintage radio hobbyists in the United States will celebrate the federal goverment's expansion of the 75 meter phone band with a bandwarming party from 3600-3800Kc starting at 0500 GMT Dec. 15, 2006. The festivities are slated to begin Thursday evening Dec. 14th, when vintage radio enthusiasts in Canada will gather around several frequencies between 3700-3800, where they already enjoy phone privileges. The Federal Communications Commission, as part of a decision to enlarge and more closely match the size of the 75 meter phone band with levels of activity, has specified enactment at midnight, Eastern time. A number of U.S. stations have been granted the use of Special Event 1x1 Call Signs to help commemorate the regulatory upgrade. By coincidence, December 2006 marks 100 years since radio pioneer experimenter Reginald Fesseden's celebrated Amplitude Modulation broadcasts, considered by many to be the first voice and music signals to be heard by the public audience for wireless. The bandwarming of 2006 will again feature the AM mode, as vintage radio enthusiasts warm up their vacuum tube gear on a December night a century later. For more information: http://amfone.net Do you Yahoo!? Everyone is raving about the all-new Yahoo! Mail beta. http://new.mail.yahoo.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] Screen Modulated 813
While its fun to play with, I think you should plan on plate modulating the setup eventually. You can experiment with screen modulation, it can be tricky to get to sound good, wont do loads of power, and depends on how the screen works as a modulator, some tubes are better (lower distortion) than others I think. I talk with someone who is screen modulating a 4cx250b to 70 watts out, and it sounds very good. To screen modulate what you have, you need to run it in class C, and using a transformer in the screen circuit, put audio on it. You adjust the screen voltage for something like 1/4 the full power class C output. A mike preamp like the berringer with a line output will do it, or an 8 ohm to single ended output transformer. I think you have to use a separate adjustable screen supply, (variac?) I think it would be real tricky to use a dropping resistor from the high voltage supply, and might be dangerous. But all you need is a 0-400? volt supply and a small transformer on the screen mod deck, with a screen voltage and current meter. You do not have to run 2000 volts on the 813 plates, the books say about 70% of the rated plate voltage works best, about 1400 volts. 1200 volts would work ok also. Since my pair of 813's is adjustable in every respect, I should tack in a transformer in the screen circuit and try the screen modulation, but just for fun, I can get 700 watts of carrier out of the rig as it is, why run it at only 100 watts or so in screen mod? Brett N2DTS -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Jack Schmidling Sent: Sunday, December 10, 2006 7:49 PM To: Discussion of AM Radio in the Amateur Service Subject: [AMRadio] Screen Modulated 813 Taking another look at my recently acquired treasure, it seems like it is going to take months to gather all the parts and build my Mantra (813's modulated by 811's) My treasure consists of a nice 4 rack cabinet, a HV power supply needing a transformer and an RF deck which was apparently a linear and a blank panel. It occurs to me that after I get the transformer, I will have nearly enough parts to build a screen modulated 813 rig. I can't seem to find any info on doing this but it seems like it could be a neat interim rig that I could have on the air in a few weeks. I understand the efficiency problems but isn't this sort of academic when talking about a max 300 w carrier? Won't two 813's produce that much even when run inefficiently? Surely it would be an improvement over using the Heath SB200 and the Ranger... no? Any thoughts? 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] Screen Modulated 813
One major advantage with some of these schemes is to run AM with reduced carrier. Heath does it with their DX60 and others. You can run that screen mod scheme in the final OR you can run it a lower level and follow that with a linear amplifier. I would defer to the RF engineering experts here as to which is the better method. Yes, I would love to read an comparative assessment of the two methods. DX-60 followed by an 813 RF linear or SB200. Versus: 813 screen modulated final using the same method that sets the quiescent carrier level at about 10% of peak signal. Which would be more efficient? I know it is just a personal preference, but I happen to think that the Heath screen mod method for reduced carrier sounds great and carries a lot of punch on the air. I have read that the Heising choke modulation method will only get the signal to be 85% modulated, which is not at all bad. It just means you have a nice fat carrier (unlike the reduced carrier methods) and a little more carrier than with plate modulation What say the transmitter design aficionados out there? 73 de AF4K, Bry I understand the efficiency problems but isn't this sort of academic when talking about a max 300 w carrier? Won't two 813's produce that much even when run inefficiently? Surely it would be an improvement over using the Heath SB200 and the Ranger... no? Any thoughts? js Jack, Screen modulation is another form of efficiency modulation that will behave a lot like an AM linear amplifier in terms of capability for a given tube. Your SB-200 has 2 X 160 watts of dissipation available, and the dual 813 has 2 X 125 watts dissipation available. IMHO the 813 in ICAS rating is more conservatively rated than the 572B, so I'd think this is a wash between the two. I have a Central electronics 600L linear amplifier with a grid driven single 813 in class Ab2. On AM the single 813 is happy at 70 watts RF out, but it will do 100 watts AM and modulate upward 100%. It does blush a little but as long as I talk the red stays away. The drive need is under 5 watts too with that 813. Screen modulation, although relatively simple, requires the screen audio drive to stay linear when the screen current varies from zero to fairly high level. This means the screen modulator needs to have a low source impedance, and some inverse feedback is helpful. One approach is to use something like a triode connected beam power tube as a cathode follower to drive the screen. You can also use a low power ( 10 watts or so ) modulator circuit with a small modulation transformer for the 813 screen. Regards, Jim JKO -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.432 / Virus Database: 268.15.15/581 - Release Date: 12/9/2006 3:41 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 __ 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] Screen Modulated 813
I wonder what tubes they are? Brett -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Jim candela Sent: Sunday, December 10, 2006 11:22 PM To: Discussion of AM Radio in the Amateur Service Subject: RE: [AMRadio] Screen Modulated 813 From Jim W5JO: As an interesting sidelight to this, I read an article on Ted/KC3OL's website some time back about modulating an SB 200 directly.. As I recall it was written by Chuck/WA0ZHH. Reply by Jim, JKO: I found the sight URL: http://www.kc3ol.dynip.com/downloads/wa0zhh.jpg JIM -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.432 / Virus Database: 268.15.15/581 - Release Date: 12/9/2006 3:41 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 __ 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] Lettering or decal for BC 610
It's a little gizmo you can get at office max, or staples, or k or wall mart. It takes tape, and you type what you want, then print it out, peel and stick. You can do real small letters, they make all colors of tape and letters, black on white, white on clear, etc. Its not like the old dymo stuff (hard plastic) that ALWAYS fell off after a short time... Brett -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED] Sent: Monday, December 11, 2006 8:56 AM To: Discussion of AM Radio in the Amateur Service Subject: RE: [AMRadio] Lettering or decal for BC 610 What is P touch, Never heard of that , I know of dry labels -- KC7HKP George Yazzolino 14801 NE 20th Circle Vancouver, Wa. 98684 Grid CN-85 [EMAIL PROTECTED] -- Original message -- From: Brett gazdzinski [EMAIL PROTECTED] I like a P touch using clear tape with white letters. You can print out whole words or multi words, in many different fonts and sizes, and just stick it on. You can trim the tape so its no bigger then the letters... I used to use daytak dry transfers then clear coat, but they got old and would not stick anymore. I eliminate the clear coat, and can peel off the P touch labels if I need to I also use it to label the chassis, on things like connections, tube sockets, etc. Brett N2DTS -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Bill Fondren Sent: Sunday, December 10, 2006 8:49 AM To: amradio@mailman.qth.net Subject: [AMRadio] Lettering or decals for BC 610 I think I sent this question to the wrong email address No telling where it went Anyway I will send it again. I just got an old BC 610 on the air. I need to paint the unit No problem with painting it, but what is the best way to get the lettering or decals on the front panel. I went to our local sign shop and the lady warned me that the computer cut letters that small would not be to good. She tried and she was correct. She said she could have the letters printed on a clear stickon sheet, something like stotch tape I guess. Has anyone tried any of the decal kits available on the internet. Found some kits that are called water slide decals, but white letters take a special kit. Hope some one out there has a good solution Bill K5PML __ 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 __ 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] Screen Modulated 813
That is really interesting. I wonder what he sets the BIAS voltage to? Interesting that it needs -200V for the negative swings There is not much information about the requirements for those two 120V AC transformers, but I imagine that they could be fairly small since they are only supplying bias voltage. Comments? 73.5 de AF4K, Bry From Jim W5JO: As an interesting sidelight to this, I read an article on Ted/KC3OL's website some time back about modulating an SB 200 directly.. As I recall it was written by Chuck/WA0ZHH. Reply by Jim, JKO: I found the sight URL: http://www.kc3ol.dynip.com/downloads/wa0zhh.jpg JIM -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.432 / Virus Database: 268.15.15/581 - Release Date: 12/9/2006 3:41 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 __ 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] Screen Modulated 813
Brett, it says they are 6336 tubes, although I think some other low Z ones like 6080 or 6AS7 would work too. Bry I wonder what tubes they are? Brett -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Jim candela Sent: Sunday, December 10, 2006 11:22 PM To: Discussion of AM Radio in the Amateur Service Subject: RE: [AMRadio] Screen Modulated 813 From Jim W5JO: As an interesting sidelight to this, I read an article on Ted/KC3OL's website some time back about modulating an SB 200 directly.. As I recall it was written by Chuck/WA0ZHH. Reply by Jim, JKO: I found the sight URL: http://www.kc3ol.dynip.com/downloads/wa0zhh.jpg JIM -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.432 / Virus Database: 268.15.15/581 - Release Date: 12/9/2006 3:41 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 __ 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] Lettering or decal for BC 610
This is a box that looks like a hand held PC...You can change fonts, size ect...Great Toy for under $50 from Office Depot and others...I have 2 ..They are made by BROTHER Tape is rather costly but worth it... W1PE -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED] Sent: Monday, December 11, 2006 7:56 AM To: Discussion of AM Radio in the Amateur Service Subject: RE: [AMRadio] Lettering or decal for BC 610 What is P touch, Never heard of that , I know of dry labels -- KC7HKP George Yazzolino 14801 NE 20th Circle Vancouver, Wa. 98684 Grid CN-85 [EMAIL PROTECTED] -- Original message -- From: Brett gazdzinski [EMAIL PROTECTED] I like a P touch using clear tape with white letters. You can print out whole words or multi words, in many different fonts and sizes, and just stick it on. You can trim the tape so its no bigger then the letters... I used to use daytak dry transfers then clear coat, but they got old and would not stick anymore. I eliminate the clear coat, and can peel off the P touch labels if I need to I also use it to label the chassis, on things like connections, tube sockets, etc. Brett N2DTS -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Bill Fondren Sent: Sunday, December 10, 2006 8:49 AM To: amradio@mailman.qth.net Subject: [AMRadio] Lettering or decals for BC 610 I think I sent this question to the wrong email address No telling where it went Anyway I will send it again. I just got an old BC 610 on the air. I need to paint the unit No problem with painting it, but what is the best way to get the lettering or decals on the front panel. I went to our local sign shop and the lady warned me that the computer cut letters that small would not be to good. She tried and she was correct. She said she could have the letters printed on a clear stickon sheet, something like stotch tape I guess. Has anyone tried any of the decal kits available on the internet. Found some kits that are called water slide decals, but white letters take a special kit. Hope some one out there has a good solution Bill K5PML __ 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 __ 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] Lettering or decal for BC 610
On 12/11/06, Bob Peters [EMAIL PROTECTED] wrote: This is a box that looks like a hand held PC...You can change fonts, size ect...Great Toy for under $50 from Office Depot and others...I have 2 ..They are made by BROTHER Tape is rather costly but worth it... W1PE Can you clear coat over these without some reaction of the tape to the clear coat? __ 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] Lettering or decals for BC 610
I believe the Brother P-Touch will also provide dry transfer tapes too. Ed, VA3ES -- Brett gazdzinski wrote: I like a P touch using clear tape with white letters. You can print out whole words or multi words, in many different fonts and sizes, and just stick it on. You can trim the tape so its no bigger then the letters... Brett N2DTS __ 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] Lettering or decal for BC 610
For the best deal on Brother P-Touch tapes, do an internet search. I recently purchased a $25.00 cartridge of TZ Flexible tape for cable identification for $13.61 plus shipping. I have nothing to do with this company other than being a customer, but I will be glad to tell you who they are if you contact me DIRECT. 73, John, W4AWM __ 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] RF Amp
Brett, I have so many projects in the works, but this one has always been a dream of mine. While I wait to find parts for the one I try to stay busy on another one. Thanks for the encouragement and good luck on your modulator. 73, Rick/K5IZ Brett gazdzinski wrote: Rick, If you have the parts on hand, it's a shame not to use them in something. I always thought it was odd that some people collect huge amounts of parts, but never do anything with them. I am the other way around, if I have nice parts, they scream at me to be used. A tube or transformer is a terrible thing to waste. I been working on the 811 modulator for the pair of 4D32's. Its almost done, and its time to think about what to build next... Brett N2DTS __ 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] Screen Modulated 813
Tubes running red on the plate is not a BIG concern. It was done all the time in commercial service. It is when they get almost white that you need to worry. A bit of cherry red is ok. Just remember what KYV said, don't exceed the plate dissipation of the tubes. The only other concern is the heat generated. If you run them hot, then be sure they are force air cooled properly and the components used in the construction is rated for CCS. Jim W5JO Jim candela wrote: On AM the single 813 is happy at 70 watts RF out, but it will do 100 watts AM and modulate upward 100%. It does blush a little but as long as I talk the red stays away. That's about how my SB200 runs. If I run much over 100w, it gets to red for my comfort. I never stop talking so I guess I am at it's peak. This would lead me to conclude that I could get at least 200w out of 2 813's in spite of the numbers. Not a quantum leap but worth the fun project. Does that sound right? 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] Screen Modulated 813
Jim Wilhite wrote: A bit of cherry red is ok. Just remember what KYV said, don't exceed the plate dissipation of the tubes. Roger but isn't color a function of plate dissipation? In other words, can one use shades of red as real world indication instead of relying on theoretical calculations? 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] Screen Modulated 813
Yes, but we in the amateur service do not even consider running them at the max. Red is ok if you take into consideration all parameters and follow design considerations. W5JO Roger but isn't color a function of plate dissipation? In other words, can one use shades of red as real world indication instead of relying on theoretical calculations? 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] Screen Modulated 813
The reason that the tube is a bit cherry red is to continually remove built-up gasses inside the tube. Dave, W3ST Publisher of the Collins Journal Secretary to the Collins Radio Association www.collinsra.com - the CRA Website Now with PayPal CRA Nets: 3.805 Mhz every Monday at 8 PM EST and 14.253 Mhz every Saturday at 12 Noon EST Collins Chatroom - Daily at 4 PM EST on 14.285 Mhz - Original Message - From: Jim Wilhite [EMAIL PROTECTED] To: Discussion of AM Radio in the Amateur Service amradio@mailman.qth.net Sent: Monday, December 11, 2006 11:03 AM Subject: Re: [AMRadio] Screen Modulated 813 Yes, but we in the amateur service do not even consider running them at the max. Red is ok if you take into consideration all parameters and follow design considerations. W5JO Roger but isn't color a function of plate dissipation? In other words, can one use shades of red as real world indication instead of relying on theoretical calculations? 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 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] Component ID please
The HV meter on my supply does not work and the series resistor inside seems to be open. No problem but there is another component across the resistor that I have never seen before and assume is a cap but don't know.. it also reads open. I posted a pic at http://schmidling.com/meter.jpg for ID. As an aside, the resistor is quaintly marked Precision but the value is 1/2 meg which is hand written in like at NBS. No decimal point, just 1/2 meg. What is really bazaar is the accuracy is 2%, also hand written. When was that ever precision? 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] Screen Modulated 813
Bry Carling wrote: One major advantage with some of these schemes is to run AM with reduced carrier. Yes, I would love to read an comparative assessment of the two methods. http://www.qsl.net/wa5bxo/asyam/aam3.html __ 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] Screen Modulated 813
Jack Schmidling wrote: Jim Wilhite wrote: A bit of cherry red is ok. Just remember what KYV said, don't exceed the plate dissipation of the tubes. Roger but isn't color a function of plate dissipation? In other words, can one use shades of red as real world indication instead of relying on theoretical calculations? in short, no. some tubes 'color-up' at different levels than others. K5SWK had a pair of 833's in his modulator.. one always showed more color than the other. Seems I remember a time when there were a pair, and one did -not- show color at all, while the other one did. He thought it wasn't working, but it was proven that it indeed was. John/BXO has 4 813's in push-pull parallel in his modulator.. at normal voltage, there's one that always showed 'a little color' when at idle. No, you can't depend on the color of the tube, to determine output of said tube. -- 73, etc __ 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] Component ID please
Jack... That looks more like a shunt to me. Rick Jack Schmidling wrote: The HV meter on my supply does not work and the series resistor inside seems to be open. No problem but there is another component across the resistor that I have never seen before and assume is a cap but don't know.. it also reads open. I posted a pic at http://schmidling.com/meter.jpg for ID. As an aside, the resistor is quaintly marked Precision but the value is 1/2 meg which is hand written in like at NBS. No decimal point, just 1/2 meg. What is really bazaar is the accuracy is 2%, also hand written. When was that ever precision? 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] Screen Modulated 813
On Mon, 11 Dec 2006, Jim Wilhite wrote: Yes, but we in the amateur service do not even consider running them at the max. Red is ok if you take into consideration all parameters and follow design considerations. Dave Knepper also writes: The reason that the tube is a bit cherry red is to continually remove built-up gasses inside the tube. There is a wealth of practical, hands-on - and also theoretical, knowledge available on this List - a rarity among reflectors to be sure. Jim has provided myself and many others with constant 'good information' regarding AM transmitting gear. But but but but: Speaking as a design engineer, lifelong tube-geek, and (moderately succesful) thermionic designer - I would like to make the point that plate incandescance may, or may not, be 'OK' depends on the device amd the regime it's run in. Unless designed for such dissipation, it is most certainly NOT OK to run many tubes at a blush. The venerable 6146 is a case in point - running the plates red in a 6146 alters them irreversibly and generally kills 'em... get a 'fresh' one, test it for Gm, run it good and red for a while, then re-test. ooops There are of course tubes designed to run red, even bright yellow - like the various radiation-cooled tubes - IIRC 4-65s, etc... There are some tubes, like the 833, that can stand a little color and not get terribly upset. Running plates red does not, in most cases, re-adsorb gasses - if anything it facilitates thier release - depends entirely on the plate alloy, thickness, and any coating, element spacing, grid material and design, spacer materials, etc., etc.. You can't just make generic generalizations like this... the situation is way more complex. Red plates also has implications for permanent grid damage - not to mention that fact that we want that plate to collect electrons, not emit a bunch of them... ;} And as for running them to the max - all tubes have a point of maximum 'efficiency' where the power transfer function is optimal. Is the plate red at that place under the curves? If it's a radiation-cooled tube, you bet. If it's a 6146 - it just died. And just who is the we you speak of? ;} I run my Valiant on the raggedy edge most of the time - and I've chewed up one brand new set of finals finding out just where that edge is... d'oh! But now I know just how to get the max out of the transmitter and still keep the Output Devices happy - even if I do make 'em sweat good and hard... Anyway - the study of the theory and design of vacuum tubes is pretty damn fascinating to me - and if anyone is interested, I have a fairly comprehensive bibliography on the subject that I'd be happy to post, if there is any interest. And seeing as how most of us are using power tubes, and building / operating devices using power tubes - might save some bucks in the long run. Just my 200 millidollar for a Monday Morning... Cheers and Best of the Season John KB6SCO DM09fg __ 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] Component ID please
No, look again, it is internal series multiplier, so that the meter will read volts with a direct hookup. If this is a 0-500 Volt meter as the picture seems to indicate, and multiplier was 500,000 ohms then the meter movement would have been a 1ma movement. I see no reason for a capacitor to bypass the resistor, maybe the meter but not the resistor. So perhaps the other device was another resistor to adjust the value so that the meter is more accurate than it was with just the one resistor. It may also be for temperature compensation. Both could be removed and the one milliamp movement used with an external resistor arrangement or divider. With the proper circuitry and switch it could be a 0-500 milliamp or 0-5KV. John, WA5BXO -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Rick Brashear Sent: Monday, December 11, 2006 10:28 AM To: Discussion of AM Radio in the Amateur Service Subject: Re: [AMRadio] Component ID please Jack... That looks more like a shunt to me. Rick Jack Schmidling wrote: The HV meter on my supply does not work and the series resistor inside seems to be open. No problem but there is another component across the resistor that I have never seen before and assume is a cap but don't know.. it also reads open. I posted a pic at http://schmidling.com/meter.jpg for ID. As an aside, the resistor is quaintly marked Precision but the value is 1/2 meg which is hand written in like at NBS. No decimal point, just 1/2 meg. What is really bazaar is the accuracy is 2%, also hand written. When was that ever precision? 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 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] Screen Modulated 813
John, you better check your copy of Eimac's classic on the Care and Feeding of Power Amplifier Tubes. Of course, running a 6146 red hot is not acceptable. I was referring to large transmitting tubes like the 4-400A's, etc. Dave, W3ST Publisher of the Collins Journal Secretary to the Collins Radio Association www.collinsra.com - the CRA Website Now with PayPal CRA Nets: 3.805 Mhz every Monday at 8 PM EST and 14.253 Mhz every Saturday at 12 Noon EST Collins Chatroom - Daily at 4 PM EST on 14.285 Mhz - Original Message - From: John Lawson [EMAIL PROTECTED] To: Discussion of AM Radio in the Amateur Service amradio@mailman.qth.net Sent: Monday, December 11, 2006 11:35 AM Subject: Re: [AMRadio] Screen Modulated 813 On Mon, 11 Dec 2006, Jim Wilhite wrote: Yes, but we in the amateur service do not even consider running them at the max. Red is ok if you take into consideration all parameters and follow design considerations. Dave Knepper also writes: The reason that the tube is a bit cherry red is to continually remove built-up gasses inside the tube. There is a wealth of practical, hands-on - and also theoretical, knowledge available on this List - a rarity among reflectors to be sure. Jim has provided myself and many others with constant 'good information' regarding AM transmitting gear. But but but but: Speaking as a design engineer, lifelong tube-geek, and (moderately succesful) thermionic designer - I would like to make the point that plate incandescance may, or may not, be 'OK' depends on the device amd the regime it's run in. Unless designed for such dissipation, it is most certainly NOT OK to run many tubes at a blush. The venerable 6146 is a case in point - running the plates red in a 6146 alters them irreversibly and generally kills 'em... get a 'fresh' one, test it for Gm, run it good and red for a while, then re-test. ooops There are of course tubes designed to run red, even bright yellow - like the various radiation-cooled tubes - IIRC 4-65s, etc... There are some tubes, like the 833, that can stand a little color and not get terribly upset. Running plates red does not, in most cases, re-adsorb gasses - if anything it facilitates thier release - depends entirely on the plate alloy, thickness, and any coating, element spacing, grid material and design, spacer materials, etc., etc.. You can't just make generic generalizations like this... the situation is way more complex. Red plates also has implications for permanent grid damage - not to mention that fact that we want that plate to collect electrons, not emit a bunch of them... ;} And as for running them to the max - all tubes have a point of maximum 'efficiency' where the power transfer function is optimal. Is the plate red at that place under the curves? If it's a radiation-cooled tube, you bet. If it's a 6146 - it just died. And just who is the we you speak of? ;} I run my Valiant on the raggedy edge most of the time - and I've chewed up one brand new set of finals finding out just where that edge is... d'oh! But now I know just how to get the max out of the transmitter and still keep the Output Devices happy - even if I do make 'em sweat good and hard... Anyway - the study of the theory and design of vacuum tubes is pretty damn fascinating to me - and if anyone is interested, I have a fairly comprehensive bibliography on the subject that I'd be happy to post, if there is any interest. And seeing as how most of us are using power tubes, and building / operating devices using power tubes - might save some bucks in the long run. Just my 200 millidollar for a Monday Morning... Cheers and Best of the Season John KB6SCO DM09fg __ 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] Component ID please
Dang! You're right again, John! I now see the series wiring. Good call. Rick/K5IZ John E. Coleman (ARS WA5BXO) wrote: No, look again, it is internal series multiplier, so that the meter will read volts with a direct hookup. If this is a 0-500 Volt meter as the picture seems to indicate, and multiplier was 500,000 ohms then the meter movement would have been a 1ma movement. I see no reason for a capacitor to bypass the resistor, maybe the meter but not the resistor. So perhaps the other device was another resistor to adjust the value so that the meter is more accurate than it was with just the one resistor. It may also be for temperature compensation. Both could be removed and the one milliamp movement used with an external resistor arrangement or divider. With the proper circuitry and switch it could be a 0-500 milliamp or 0-5KV. 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] Screen Modulated 813
If you have one tube like aan 833A running slightly cherry and the other is not showing any color, then, the latter is a weak tube. The former has low emission, in other words. Dave, W3ST Publisher of the Collins Journal Secretary to the Collins Radio Association www.collinsra.com - the CRA Website Now with PayPal CRA Nets: 3.805 Mhz every Monday at 8 PM EST and 14.253 Mhz every Saturday at 12 Noon EST Collins Chatroom - Daily at 4 PM EST on 14.285 Mhz - Original Message - From: Geoff/W5OMR [EMAIL PROTECTED] To: Discussion of AM Radio in the Amateur Service amradio@mailman.qth.net Sent: Monday, December 11, 2006 11:23 AM Subject: Re: [AMRadio] Screen Modulated 813 Jack Schmidling wrote: Jim Wilhite wrote: A bit of cherry red is ok. Just remember what KYV said, don't exceed the plate dissipation of the tubes. Roger but isn't color a function of plate dissipation? In other words, can one use shades of red as real world indication instead of relying on theoretical calculations? in short, no. some tubes 'color-up' at different levels than others. K5SWK had a pair of 833's in his modulator.. one always showed more color than the other. Seems I remember a time when there were a pair, and one did -not- show color at all, while the other one did. He thought it wasn't working, but it was proven that it indeed was. John/BXO has 4 813's in push-pull parallel in his modulator.. at normal voltage, there's one that always showed 'a little color' when at idle. No, you can't depend on the color of the tube, to determine output of said tube. -- 73, etc __ 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] Component ID please
Rick Brashear wrote: Dang! You're right again, John! I now see the series wiring. Good call. Rick/K5IZ John E. Coleman (ARS WA5BXO) wrote: Forget it, Rick. that guy walks through 'complicated' electronic formulas like a cow walks through grass. He's -real- good! -- 73, etc __ 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] Screen Modulated 813
david knepper wrote: If you have one tube like aan 833A running slightly cherry and the other is not showing any color, then, the latter is a weak tube. The former has low emission, in other words. Not all 833's are created equal. Your statement is not necessarily true. -- etc __ 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] Step Start
I just ordered a trans for my pwsup and need to work around the hi/low step start designed into it. It uses the 220 line to provide 110 or 220 to the transformer. The new one is 110 so I do not have this option. I plan to reroute the hi/low switch to a resistor or better yet a light bulb to reduce in input voltage at start up. The original was limited to 110v but with a resistor, I can provide any start up voltage I want so I need some help figuring out what resistance would be best. There is a time delay relay that precludes putting any voltage on the primary for one minute to allow the tubes to warm up so I presume the hi/lo is to reduce the surge upon charging up the caps. This is a choke input with two 4 mf in parallel across the output and somewhere it seemed to imply that the step start was only needed for cap input. As far as I can get with the heavy math, it seems like the resistor required would only be a few watts as it is only dealing with the 100k bleeder as a load. Thoughts please. 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] Screen Modulated 813
You are most correct John, I was speaking of power tubes not the lesser cousins. I didn't make that clear but in light of the subject, I plead not guilty. Jim W5JO - Original Message - From: John Lawson [EMAIL PROTECTED] To: Discussion of AM Radio in the Amateur Service amradio@mailman.qth.net Sent: Monday, December 11, 2006 10:35 AM Subject: Re: [AMRadio] Screen Modulated 813 On Mon, 11 Dec 2006, Jim Wilhite wrote: Yes, but we in the amateur service do not even consider running them at the max. Red is ok if you take into consideration all parameters and follow design considerations. Dave Knepper also writes: The reason that the tube is a bit cherry red is to continually remove built-up gasses inside the tube. There is a wealth of practical, hands-on - and also theoretical, knowledge available on this List - a rarity among reflectors to be sure. Jim has provided myself and many others with constant 'good information' regarding AM transmitting gear. But but but but: Speaking as a design engineer, lifelong tube-geek, and (moderately succesful) thermionic designer - I would like to make the point that plate incandescance may, or may not, be 'OK' depends on the device amd the regime it's run in. Unless designed for such dissipation, it is most certainly NOT OK to run many tubes at a blush. The venerable 6146 is a case in point - running the plates red in a 6146 alters them irreversibly and generally kills 'em... get a 'fresh' one, test it for Gm, run it good and red for a while, then re-test. ooops There are of course tubes designed to run red, even bright yellow - like the various radiation-cooled tubes - IIRC 4-65s, etc... There are some tubes, like the 833, that can stand a little color and not get terribly upset. Running plates red does not, in most cases, re-adsorb gasses - if anything it facilitates thier release - depends entirely on the plate alloy, thickness, and any coating, element spacing, grid material and design, spacer materials, etc., etc.. You can't just make generic generalizations like this... the situation is way more complex. Red plates also has implications for permanent grid damage - not to mention that fact that we want that plate to collect electrons, not emit a bunch of them... ;} And as for running them to the max - all tubes have a point of maximum 'efficiency' where the power transfer function is optimal. Is the plate red at that place under the curves? If it's a radiation-cooled tube, you bet. If it's a 6146 - it just died. And just who is the we you speak of? ;} I run my Valiant on the raggedy edge most of the time - and I've chewed up one brand new set of finals finding out just where that edge is... d'oh! But now I know just how to get the max out of the transmitter and still keep the Output Devices happy - even if I do make 'em sweat good and hard... Anyway - the study of the theory and design of vacuum tubes is pretty damn fascinating to me - and if anyone is interested, I have a fairly comprehensive bibliography on the subject that I'd be happy to post, if there is any interest. And seeing as how most of us are using power tubes, and building / operating devices using power tubes - might save some bucks in the long run. Just my 200 millidollar for a Monday Morning... Cheers and Best of the Season John KB6SCO DM09fg __ 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] Screen Modulated 813
Most 813's had graphite plates, and I never remember them showing color, I always thought that would be way beyond what they were good for, or was good for them...if they were glowing! 811/812 can show some color, but I don't think its GOOD for them to do so. 6146, 6l6, 4D32, and others of their ilk don't normally show color, 4-65/125/250/400/1000 can, and its ok. So can the TH and TL series, they can run almost white hot plates. The harder you run them the shorter they last, and have less room for mistakes (we don't make THOSE here). While I don't often run tubes at the maximum plate dissipation, I do greatly exceed the plate voltage ratings, I don't know where they came up with the ratings, but you seem to be able to double it without problems on most tubes. I have been running a pair of 4D32's at 1200 volts under modulation, without problems, they are rated for 600 volts in plate modulated AM service... Brett N2DTS On Mon, 11 Dec 2006, Jim Wilhite wrote: Yes, but we in the amateur service do not even consider running them at the max. Red is ok if you take into consideration all parameters and follow design considerations. Dave Knepper also writes: The reason that the tube is a bit cherry red is to continually remove built-up gasses inside the tube. There is a wealth of practical, hands-on - and also theoretical, knowledge available on this List - a rarity among reflectors to be sure. Jim has provided myself and many others with constant 'good information' regarding AM transmitting gear. But but but but: Speaking as a design engineer, lifelong tube-geek, and (moderately succesful) thermionic designer - I would like to make the point that plate incandescance may, or may not, be 'OK' depends on the device amd the regime it's run in. Unless designed for such dissipation, it is most certainly NOT OK to run many tubes at a blush. The venerable 6146 is a case in point - running the plates red in a 6146 alters them irreversibly and generally kills 'em... get a 'fresh' one, test it for Gm, run it good and red for a while, then re-test. ooops There are of course tubes designed to run red, even bright yellow - like the various radiation-cooled tubes - IIRC 4-65s, etc... There are some tubes, like the 833, that can stand a little color and not get terribly upset. Running plates red does not, in most cases, re-adsorb gasses - if anything it facilitates thier release - depends entirely on the plate alloy, thickness, and any coating, element spacing, grid material and design, spacer materials, etc., etc.. You can't just make generic generalizations like this... the situation is way more complex. Red plates also has implications for permanent grid damage - not to mention that fact that we want that plate to collect electrons, not emit a bunch of them... ;} And as for running them to the max - all tubes have a point of maximum 'efficiency' where the power transfer function is optimal. Is the plate red at that place under the curves? If it's a radiation-cooled tube, you bet. If it's a 6146 - it just died. And just who is the we you speak of? ;} I run my Valiant on the raggedy edge most of the time - and I've chewed up one brand new set of finals finding out just where that edge is... d'oh! But now I know just how to get the max out of the transmitter and still keep the Output Devices happy - even if I do make 'em sweat good and hard... Anyway - the study of the theory and design of vacuum tubes is pretty damn fascinating to me - and if anyone is interested, I have a fairly comprehensive bibliography on the subject that I'd be happy to post, if there is any interest. And seeing as how most of us are using power tubes, and building / operating devices using power tubes - might save some bucks in the long run. Just my 200 millidollar for a Monday Morning... Cheers and Best of the Season John KB6SCO DM09fg __ 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] Screen Modulated 813
Zirconium getters best at about 1000 degrees C, this why large metal anode transmitting tubes like the 4-400A, 4-1000A, and 3-500 must be operated with a dull red to red anode color. Zirconium also releases some gasses and absorbs other gasses at various temperatures. The varying temperature across the length of the anode (and as the anode heats and cools) allows the gettering agent to absorb a wide variety of gasses. You can do what you will but I like to run a little color on my large bottles. Dave, W3ST Publisher of the Collins Journal Secretary to the Collins Radio Association www.collinsra.com - the CRA Website Now with PayPal CRA Nets: 3.805 Mhz every Monday at 8 PM EST and 14.253 Mhz every Saturday at 12 Noon EST Collins Chatroom - Daily at 4 PM EST on 14.285 Mhz - Original Message - From: John Lawson [EMAIL PROTECTED] To: Discussion of AM Radio in the Amateur Service amradio@mailman.qth.net Sent: Monday, December 11, 2006 12:00 PM Subject: Re: [AMRadio] Screen Modulated 813 On Mon, 11 Dec 2006, david knepper wrote: John, you better check your copy of Eimac's classic on the Care and Feeding of Power Amplifier Tubes. Which edition? I think I have 'em all... ;} I strenuously re-iterate the point that making a sweeping omnibus generalization about 'red plates re-adsorbing gasses' is just that: a generalization, and can be (disastrously) not true in a lot of cases Of course, running a 6146 red hot is not acceptable. I was referring to large transmitting tubes like the 4-400A's, etc. Y'all didn't say that - you said ...the tube... Nit-pickingly yours: John KB6SCO DM09fg __ 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] Screen Modulated 813
On Mon, 11 Dec 2006, Jim Wilhite wrote: You are most correct John, I was speaking of power tubes not the lesser cousins. I didn't make that clear but in light of the subject, I plead not guilty. Well - speaking as someone who will very soon be conducting QSOs via 833s and 807s (*) - I plan to test a few of your assertions... ;} The difference between 'Theory' and 'Practice' is usually much less in theory, than it is in practice Cheers and Best of the Season John KB6SCO DM09fg (*) I'm rescuing an RCA BTA-1MX this weekend - I'll have it on the air as soon as I can work out the re-tuning for 80M...woo hoo!! __ 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] Step Start
I plan to reroute the hi/low switch to a resistor or better yet a light bulb to reduce in input voltage at start up. Light bulb wont do, too high a resistance. Some used those old ceramic heating elements that were used in very old fashioned space heaters, looked like satellite dishes sort of... The original was limited to 110v but with a resistor, I can provide any start up voltage I want so I need some help figuring out what resistance would be best. I would guess around 5 to 10 ohms, more on the 5 ohm side. Too high and you will get only 100 volts in the 1/2 second of step start. You want about 1/2 voltage... There is a time delay relay that precludes putting any voltage on the primary for one minute to allow the tubes to warm up so I presume the hi/lo is to reduce the surge upon charging up the caps. That time delay is for the mercury vapor rectifiers. I use solid state diodes (1 amp at 14kv), less muss and fuss... This is a choke input with two 4 mf in parallel across the output and somewhere it seemed to imply that the step start was only needed for cap input. As far as I can get with the heavy math, it seems like the resistor required would only be a few watts as it is only dealing with the 100k bleeder as a load. Not much average power, but on step start peak currents are high, even with choke input. Make the step start resistor 25 or better watts. The step start resistor only comes into play for the 1/2 second during step start, the time delay relay should them short it out. If you want a 1/2 voltage tune position, then the resistor has got to be a good size... Brett N2DTS Thoughts please. 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
[AMRadio] Re: Screen Modulated 813
Bry Carling writes: DX-60 followed by an 813 RF linear or SB200. Versus: 813 screen modulated final using the same method that sets the quiescent carrier level at about 10% of peak signal. Which would be more efficient? It's my understanding that from a 1st order analysis (ignoring subtleties like what plate voltage they are being run at, any differences in efficiencies between the tube types, output network design, etc, etc.), the plate efficiencies would theoretically be the same between a screen-modulated stage and a class AB linear amplifier stage amplifying an AM signal, since they are both essentially efficiency modulation techniques. 73., -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] Screen Modulated 813
On Mon, 11 Dec 2006, david knepper wrote: Zirconium getters best at about 1000 degrees C, this why large metal anode transmitting tubes like the 4-400A, 4-1000A, and 3-500 must be operated with a dull red to red anode color. Zirconium also releases some gasses and [snip] You can do what you will but I like to run a little color on my large bottles. You're making the same point I am, Dave: visible plate incandescance can be 'optimum' - 'acceptable' - 'acceptable for x-time' - 'not recommended - or 'disastrous'. It's device-dependent! All of it is a matter of physics, physical electronics, metallurgy, and the well-known, well-documented aspects of thermionic device design and contruction. It is not so much a matter of desire or personal inclination, as it is: at the operating point you have set for the particular device in use - is it within the manufacturer's ratings for that service? If the plate shows visible color, so be it. If, on the other hand, a noticeable blush means the tube is exceeding it's design-spec, then some consequences will come from that... good or bad I cannot say. If an expensive power tube has it's useful life cut in half, or more, from 'abuse' - especially if it's a fairly 'rare' type - well then Dat wuz all I wuz tryin' t' say. Cheers and Best of the Season! John KB6SCO DM09fg __ 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] Step Start
Jack I would dispense with the startup circuit. With the choke input filter system and only 4mf of output capacitance you want need a start up circuit. When I hit the push to talk switch is when my PS plate XFMR comes on. The heaters to the 866 are on all the time. John -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Jack Schmidling Sent: Monday, December 11, 2006 11:20 AM To: Discussion of AM Radio in the Amateur Service Subject: [AMRadio] Step Start I just ordered a trans for my pwsup and need to work around the hi/low step start designed into it. It uses the 220 line to provide 110 or 220 to the transformer. The new one is 110 so I do not have this option. I plan to reroute the hi/low switch to a resistor or better yet a light bulb to reduce in input voltage at start up. The original was limited to 110v but with a resistor, I can provide any start up voltage I want so I need some help figuring out what resistance would be best. There is a time delay relay that precludes putting any voltage on the primary for one minute to allow the tubes to warm up so I presume the hi/lo is to reduce the surge upon charging up the caps. This is a choke input with two 4 mf in parallel across the output and somewhere it seemed to imply that the step start was only needed for cap input. As far as I can get with the heavy math, it seems like the resistor required would only be a few watts as it is only dealing with the 100k bleeder as a load. Thoughts please. 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] Screen Modulated 813
The 813 and 572 are tubes that should never show color. 73 Gary K4FMX -Original Message- From: [EMAIL PROTECTED] [mailto:amradio- [EMAIL PROTECTED] On Behalf Of Jim Wilhite Sent: Monday, December 11, 2006 12:24 PM To: Discussion of AM Radio in the Amateur Service Subject: Re: [AMRadio] Screen Modulated 813 You are most correct John, I was speaking of power tubes not the lesser cousins. I didn't make that clear but in light of the subject, I plead not guilty. Jim W5JO - Original Message - From: John Lawson [EMAIL PROTECTED] To: Discussion of AM Radio in the Amateur Service amradio@mailman.qth.net Sent: Monday, December 11, 2006 10:35 AM Subject: Re: [AMRadio] Screen Modulated 813 On Mon, 11 Dec 2006, Jim Wilhite wrote: Yes, but we in the amateur service do not even consider running them at the max. Red is ok if you take into consideration all parameters and follow design considerations. Dave Knepper also writes: The reason that the tube is a bit cherry red is to continually remove built-up gasses inside the tube. There is a wealth of practical, hands-on - and also theoretical, knowledge available on this List - a rarity among reflectors to be sure. Jim has provided myself and many others with constant 'good information' regarding AM transmitting gear. But but but but: Speaking as a design engineer, lifelong tube-geek, and (moderately succesful) thermionic designer - I would like to make the point that plate incandescance may, or may not, be 'OK' depends on the device amd the regime it's run in. Unless designed for such dissipation, it is most certainly NOT OK to run many tubes at a blush. The venerable 6146 is a case in point - running the plates red in a 6146 alters them irreversibly and generally kills 'em... get a 'fresh' one, test it for Gm, run it good and red for a while, then re-test. ooops There are of course tubes designed to run red, even bright yellow - like the various radiation-cooled tubes - IIRC 4-65s, etc... There are some tubes, like the 833, that can stand a little color and not get terribly upset. Running plates red does not, in most cases, re-adsorb gasses - if anything it facilitates thier release - depends entirely on the plate alloy, thickness, and any coating, element spacing, grid material and design, spacer materials, etc., etc.. You can't just make generic generalizations like this... the situation is way more complex. Red plates also has implications for permanent grid damage - not to mention that fact that we want that plate to collect electrons, not emit a bunch of them... ;} And as for running them to the max - all tubes have a point of maximum 'efficiency' where the power transfer function is optimal. Is the plate red at that place under the curves? If it's a radiation-cooled tube, you bet. If it's a 6146 - it just died. And just who is the we you speak of? ;} I run my Valiant on the raggedy edge most of the time - and I've chewed up one brand new set of finals finding out just where that edge is... d'oh! But now I know just how to get the max out of the transmitter and still keep the Output Devices happy - even if I do make 'em sweat good and hard... Anyway - the study of the theory and design of vacuum tubes is pretty damn fascinating to me - and if anyone is interested, I have a fairly comprehensive bibliography on the subject that I'd be happy to post, if there is any interest. And seeing as how most of us are using power tubes, and building / operating devices using power tubes - might save some bucks in the long run. Just my 200 millidollar for a Monday Morning... Cheers and Best of the Season John KB6SCO DM09fg __ 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 __ 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] Antenna's..
Hi Brett, OK, I've never run one before, this is my first 'multi' band. But I'll clue you on what I found... I've got one half of the dipole at about level. The other side drops down... not like an inverted V, but a slight slope. The slope side also has a slight dogleg. The entire antenna is more of an L than a dipole, and I think it ended up at about 123' 9. It is made with insulated stranded #14 copper clad steel wire. (no stretching) Since I knew it would be WAY out of resonance, I used real porcelain end insulators and a one foot glass insulator in the middle. I didn't want to be melting any insulators while on AM. I use RG 8 coax. On AM, if I use one of my Apache's or a DX-100 there are no coax cooking or heating problems. I am nearly finished restoring a home brew 813 modulated by a pair of 811's. While doing full power on the air tests the coax gets warm on the bands above 40 meters --- that's not good. But I don't have time to do anything about it yet. I imagine I'll have to switch the garage shack (where the home brew is) to open wire feeder, but??? My modern rigs, Icom's, or vintage SSB gear doesn't even begin to heat up the coax on SSB or CW, even if I use my ancient Warrior amp. I've never checked it on PSK, but I doubt it would get hot. I use the 2060 and have to admit, it's a great tuner. It is kind of a pain having another stage to tune, but the antenna sure works great for everything from chewin the rag local on 75 and 160 to DX. 73 Merry Christmas Craig K6QI At 05:40 AM 12/11/2006, you wrote: Craig, Thanks for the info. What power do you run? I might be able to get 110 feet, maybe a little more if I put the wire in the tree branches...insulated wire? I have found that the RG214 coax can get real hot if I run into an antenna that is not resonant... I have the heath 2060a, although I hate to use it. Brett N2DTS -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Craig Carter Sent: Friday, December 08, 2006 11:33 PM To: Discussion of AM Radio in the Amateur Service Subject: RE: Re: [AMRadio] Antenna's.. I had one of the Alpha Delta 40 80 and a multi band Alpha Delta dipoles. With a tuner, the multi band was one of the best dummy loads I've ever had. The 80 / 40 trapless dipole was 'eh' on 80, ok on 40. I now have a 125' dipole, bent all over he!! and gone, and a Heath SA 2060 tuner with RG 8. Works great on every band I try it on, including 6 and 2! I would put up the longest wire I could fit, get a BAT (big 'butted' tuner) and have fun. 73 Craig K6QI __ 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
[AMRadio] FW: Noise in the shack
BJ WB5PKD and I are fighting noise again Noise in the shack Saturday night - Sunday morning - on the HQ145 was S9+ and Don (KYV) was 40 over with noise when he hit 60 over at the top of the meter was when the noise when quite BJ sent this to me after the rain, thought it might get a laugh. John, WA5BXO -Original Message- From: BJ Lowery [mailto:[EMAIL PROTECTED] Sent: Monday, December 11, 2006 12:33 PM To: John Coleman Subject: Noise in the shack I checked the level in the shack this morning. When I turned everything on I had about a 2 on the meter. Not bad for out there. It had climbed to a 3.5 when I came into the house. I checked the receiver in the house and only had a 1, then I realized I had left the antenna connected to the shack receiver. Conclusions, to do away with the noise do not hook up an antenna. HiHi. I still could hear noise on the AM radio around 1600 KHz. I did not go looking for it yet. Later, BJ __ 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] Screen Modulated 813
Exactly, John. If a transmitting tube is operating within manufacturer's specifications and does not show color then don't increase the plate current or voltage to do so. Many transmitting tubes are meant to show some blushing, particularly, modulators - this is normal and acceptable. You wouldn't, of course want to this occur with a 6146, etc. My point was that many hams mistakenly think that with some tubes like those that I mention there should be no blushing - quite the contrary. Blushing is good for tubes and, of course, for women, under certain circumstances! Merry Christmas Dave, W3ST Publisher of the Collins Journal Secretary to the Collins Radio Association www.collinsra.com - the CRA Website Now with PayPal CRA Nets: 3.805 Mhz every Monday at 8 PM EST and 14.253 Mhz every Saturday at 12 Noon EST Collins Chatroom - Daily at 4 PM EST on 14.285 Mhz - Original Message - From: John Lawson [EMAIL PROTECTED] To: Discussion of AM Radio in the Amateur Service amradio@mailman.qth.net Sent: Monday, December 11, 2006 12:50 PM Subject: Re: [AMRadio] Screen Modulated 813 On Mon, 11 Dec 2006, david knepper wrote: Zirconium getters best at about 1000 degrees C, this why large metal anode transmitting tubes like the 4-400A, 4-1000A, and 3-500 must be operated with a dull red to red anode color. Zirconium also releases some gasses and [snip] You can do what you will but I like to run a little color on my large bottles. You're making the same point I am, Dave: visible plate incandescance can be 'optimum' - 'acceptable' - 'acceptable for x-time' - 'not recommended - or 'disastrous'. It's device-dependent! All of it is a matter of physics, physical electronics, metallurgy, and the well-known, well-documented aspects of thermionic device design and contruction. It is not so much a matter of desire or personal inclination, as it is: at the operating point you have set for the particular device in use - is it within the manufacturer's ratings for that service? If the plate shows visible color, so be it. If, on the other hand, a noticeable blush means the tube is exceeding it's design-spec, then some consequences will come from that... good or bad I cannot say. If an expensive power tube has it's useful life cut in half, or more, from 'abuse' - especially if it's a fairly 'rare' type - well then Dat wuz all I wuz tryin' t' say. Cheers and Best of the Season! John KB6SCO DM09fg __ 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] Screen Modulated 813
Did you ever know that the 811A's in the Collins 30L-1 do show color under modulation? If any one of the four tubes does not, then, that tube should be replaced. An 813 normally does not show color, unless the plate is the metal variety and not the carbon plate. I would agree that this tube should operate without any blushing whatsoever. Dave, W3ST Publisher of the Collins Journal Secretary to the Collins Radio Association www.collinsra.com - the CRA Website Now with PayPal CRA Nets: 3.805 Mhz every Monday at 8 PM EST and 14.253 Mhz every Saturday at 12 Noon EST Collins Chatroom - Daily at 4 PM EST on 14.285 Mhz - Original Message - From: Gary Schafer [EMAIL PROTECTED] To: 'Discussion of AM Radio in the Amateur Service' amradio@mailman.qth.net Sent: Monday, December 11, 2006 1:34 PM Subject: RE: [AMRadio] Screen Modulated 813 The 813 and 572 are tubes that should never show color. 73 Gary K4FMX -Original Message- From: [EMAIL PROTECTED] [mailto:amradio- [EMAIL PROTECTED] On Behalf Of Jim Wilhite Sent: Monday, December 11, 2006 12:24 PM To: Discussion of AM Radio in the Amateur Service Subject: Re: [AMRadio] Screen Modulated 813 You are most correct John, I was speaking of power tubes not the lesser cousins. I didn't make that clear but in light of the subject, I plead not guilty. Jim W5JO - Original Message - From: John Lawson [EMAIL PROTECTED] To: Discussion of AM Radio in the Amateur Service amradio@mailman.qth.net Sent: Monday, December 11, 2006 10:35 AM Subject: Re: [AMRadio] Screen Modulated 813 On Mon, 11 Dec 2006, Jim Wilhite wrote: Yes, but we in the amateur service do not even consider running them at the max. Red is ok if you take into consideration all parameters and follow design considerations. Dave Knepper also writes: The reason that the tube is a bit cherry red is to continually remove built-up gasses inside the tube. There is a wealth of practical, hands-on - and also theoretical, knowledge available on this List - a rarity among reflectors to be sure. Jim has provided myself and many others with constant 'good information' regarding AM transmitting gear. But but but but: Speaking as a design engineer, lifelong tube-geek, and (moderately succesful) thermionic designer - I would like to make the point that plate incandescance may, or may not, be 'OK' depends on the device amd the regime it's run in. Unless designed for such dissipation, it is most certainly NOT OK to run many tubes at a blush. The venerable 6146 is a case in point - running the plates red in a 6146 alters them irreversibly and generally kills 'em... get a 'fresh' one, test it for Gm, run it good and red for a while, then re-test. ooops There are of course tubes designed to run red, even bright yellow - like the various radiation-cooled tubes - IIRC 4-65s, etc... There are some tubes, like the 833, that can stand a little color and not get terribly upset. Running plates red does not, in most cases, re-adsorb gasses - if anything it facilitates thier release - depends entirely on the plate alloy, thickness, and any coating, element spacing, grid material and design, spacer materials, etc., etc.. You can't just make generic generalizations like this... the situation is way more complex. Red plates also has implications for permanent grid damage - not to mention that fact that we want that plate to collect electrons, not emit a bunch of them... ;} And as for running them to the max - all tubes have a point of maximum 'efficiency' where the power transfer function is optimal. Is the plate red at that place under the curves? If it's a radiation-cooled tube, you bet. If it's a 6146 - it just died. And just who is the we you speak of? ;} I run my Valiant on the raggedy edge most of the time - and I've chewed up one brand new set of finals finding out just where that edge is... d'oh! But now I know just how to get the max out of the transmitter and still keep the Output Devices happy - even if I do make 'em sweat good and hard... Anyway - the study of the theory and design of vacuum tubes is pretty damn fascinating to me - and if anyone is interested, I have a fairly comprehensive bibliography on the subject that I'd be happy to post, if there is any interest. And seeing as how most of us are using power tubes, and building / operating devices using power tubes - might save some bucks in the long run. Just my 200 millidollar for a Monday Morning... Cheers and Best of the Season John KB6SCO DM09fg __ 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
RE: [AMRadio] Screen Modulated 813
The 811A should show a barely perceptible red color at maximum dissipation (per the RCA tube manual). The 30L-1 pushes the tubes a little beyond their limits. Add a little speech processing and they get pushed even harder. 73 Gary K4FMX -Original Message- From: david knepper [mailto:[EMAIL PROTECTED] Sent: Monday, December 11, 2006 2:09 PM To: [EMAIL PROTECTED]; Discussion of AM Radio in the Amateur Service Subject: Re: [AMRadio] Screen Modulated 813 Did you ever know that the 811A's in the Collins 30L-1 do show color under modulation? If any one of the four tubes does not, then, that tube should be replaced. An 813 normally does not show color, unless the plate is the metal variety and not the carbon plate. I would agree that this tube should operate without any blushing whatsoever. Dave, W3ST Publisher of the Collins Journal Secretary to the Collins Radio Association www.collinsra.com - the CRA Website Now with PayPal CRA Nets: 3.805 Mhz every Monday at 8 PM EST and 14.253 Mhz every Saturday at 12 Noon EST Collins Chatroom - Daily at 4 PM EST on 14.285 Mhz - Original Message - From: Gary Schafer [EMAIL PROTECTED] To: 'Discussion of AM Radio in the Amateur Service' amradio@mailman.qth.net Sent: Monday, December 11, 2006 1:34 PM Subject: RE: [AMRadio] Screen Modulated 813 The 813 and 572 are tubes that should never show color. 73 Gary K4FMX -Original Message- From: [EMAIL PROTECTED] [mailto:amradio- [EMAIL PROTECTED] On Behalf Of Jim Wilhite Sent: Monday, December 11, 2006 12:24 PM To: Discussion of AM Radio in the Amateur Service Subject: Re: [AMRadio] Screen Modulated 813 You are most correct John, I was speaking of power tubes not the lesser cousins. I didn't make that clear but in light of the subject, I plead not guilty. Jim W5JO - Original Message - From: John Lawson [EMAIL PROTECTED] To: Discussion of AM Radio in the Amateur Service amradio@mailman.qth.net Sent: Monday, December 11, 2006 10:35 AM Subject: Re: [AMRadio] Screen Modulated 813 On Mon, 11 Dec 2006, Jim Wilhite wrote: Yes, but we in the amateur service do not even consider running them at the max. Red is ok if you take into consideration all parameters and follow design considerations. Dave Knepper also writes: The reason that the tube is a bit cherry red is to continually remove built-up gasses inside the tube. There is a wealth of practical, hands-on - and also theoretical, knowledge available on this List - a rarity among reflectors to be sure. Jim has provided myself and many others with constant 'good information' regarding AM transmitting gear. But but but but: Speaking as a design engineer, lifelong tube-geek, and (moderately succesful) thermionic designer - I would like to make the point that plate incandescance may, or may not, be 'OK' depends on the device amd the regime it's run in. Unless designed for such dissipation, it is most certainly NOT OK to run many tubes at a blush. The venerable 6146 is a case in point - running the plates red in a 6146 alters them irreversibly and generally kills 'em... get a 'fresh' one, test it for Gm, run it good and red for a while, then re-test. ooops There are of course tubes designed to run red, even bright yellow - like the various radiation-cooled tubes - IIRC 4-65s, etc... There are some tubes, like the 833, that can stand a little color and not get terribly upset. Running plates red does not, in most cases, re-adsorb gasses - if anything it facilitates thier release - depends entirely on the plate alloy, thickness, and any coating, element spacing, grid material and design, spacer materials, etc., etc.. You can't just make generic generalizations like this... the situation is way more complex. Red plates also has implications for permanent grid damage - not to mention that fact that we want that plate to collect electrons, not emit a bunch of them... ;} And as for running them to the max - all tubes have a point of maximum 'efficiency' where the power transfer function is optimal. Is the plate red at that place under the curves? If it's a radiation-cooled tube, you bet. If it's a 6146 - it just died. And just who is the we you speak of? ;} I run my Valiant on the raggedy edge most of the time - and I've chewed up one brand new set of finals finding out just where that edge is... d'oh! But now I know just how to get the max out of the transmitter and still keep the Output Devices happy - even if I do make 'em sweat good and hard... Anyway - the study of the theory and design of vacuum tubes is pretty damn fascinating to me - and if anyone is interested, I have a fairly comprehensive bibliography on the subject
[AMRadio] Re: Screen Modulated 813
david knepper writes: Zirconium getters best at about 1000 degrees C, this why large metal anode transmitting tubes like the 4-400A, 4-1000A, and 3-500 must be operated with a dull red to red anode color. It's also why it's used to encrust tweezers ;) -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: Re: [AMRadio] Antenna's..
Yes, I think it can get to the point where its important, say if you run 700 watts of carrier power and make long transmissions Now open wire line does not have that problem, but you need a balanced tuner. Shielding a balanced tuner that is good for 700 watts of carrier, and making it easy to jump between 160 and 10 meters seems a bit tough to do. Using an unbalanced tuner on a non resonant antenna at high power does not seem to work very well, the tuner might be fine, but losses in the coax are high, in other places you might be at a high voltage point and have arcing the tuner. That is why I might try the alpha delta, its not going to work great on 160, only fair on 80, but it should be able to be made resonant enough to allow a tuner or no tuner operation. At least, that is what THEY say... Brett N2DTS -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Craig Carter Sent: Monday, December 11, 2006 1:36 PM To: Discussion of AM Radio in the Amateur Service Subject: RE: Re: [AMRadio] Antenna's.. Hi Brett, OK, I've never run one before, this is my first 'multi' band. But I'll clue you on what I found... I've got one half of the dipole at about level. The other side drops down... not like an inverted V, but a slight slope. The slope side also has a slight dogleg. The entire antenna is more of an L than a dipole, and I think it ended up at about 123' 9. It is made with insulated stranded #14 copper clad steel wire. (no stretching) Since I knew it would be WAY out of resonance, I used real porcelain end insulators and a one foot glass insulator in the middle. I didn't want to be melting any insulators while on AM. I use RG 8 coax. On AM, if I use one of my Apache's or a DX-100 there are no coax cooking or heating problems. I am nearly finished restoring a home brew 813 modulated by a pair of 811's. While doing full power on the air tests the coax gets warm on the bands above 40 meters --- that's not good. But I don't have time to do anything about it yet. I imagine I'll have to switch the garage shack (where the home brew is) to open wire feeder, but??? My modern rigs, Icom's, or vintage SSB gear doesn't even begin to heat up the coax on SSB or CW, even if I use my ancient Warrior amp. I've never checked it on PSK, but I doubt it would get hot. I use the 2060 and have to admit, it's a great tuner. It is kind of a pain having another stage to tune, but the antenna sure works great for everything from chewin the rag local on 75 and 160 to DX. 73 Merry Christmas Craig K6QI At 05:40 AM 12/11/2006, you wrote: Craig, Thanks for the info. What power do you run? I might be able to get 110 feet, maybe a little more if I put the wire in the tree branches...insulated wire? I have found that the RG214 coax can get real hot if I run into an antenna that is not resonant... I have the heath 2060a, although I hate to use it. Brett N2DTS -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Craig Carter Sent: Friday, December 08, 2006 11:33 PM To: Discussion of AM Radio in the Amateur Service Subject: RE: Re: [AMRadio] Antenna's.. I had one of the Alpha Delta 40 80 and a multi band Alpha Delta dipoles. With a tuner, the multi band was one of the best dummy loads I've ever had. The 80 / 40 trapless dipole was 'eh' on 80, ok on 40. I now have a 125' dipole, bent all over he!! and gone, and a Heath SA 2060 tuner with RG 8. Works great on every band I try it on, including 6 and 2! I would put up the longest wire I could fit, get a BAT (big 'butted' tuner) and have fun. 73 Craig K6QI __ 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 __ 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] Re: Screen Modulated 813
On Mon, 11 Dec 2006, ne1s wrote: It's also why it's used to encrust tweezers ;) Perhaps you can also tell me why dennilfloss bushes will grow in Montana - but do so badly here in NoNev? Of course I could always *move* to Montana Cheers and Best of the Season John KB6SCO Pygmy Pony __ 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] gettering, 813s and 833s
As Brett (N2DTS) and Gary (K4FMX) both stated, the 813 should not run with color on the plate, as they use a graphite anode. RCA stated this in their handbooks, Plate shows no color when tube is operated at maximum CCS or ICAS ratings. 833A datasheet says Plate shows and orange-red color when tube is operated a maximunm CCS or ICAS ratings. Taking an 813 into the cherry is not a good idea if you want the tube to last very long. I believe that we are all in agreement on that manufacturers recommendation, now. This is the first i have ever heard that you want anode to be glowing in order to get better gettering action (see below). I would be interested in knowing the source of this info. Normally in the big tubes I work with (most are 100 - 1000 kW range) we get the most outgassing when we overwork tubes, or run them at higher duty factor. This advice would seem to be limited to medium sized tubes with zirc getters then, as in the large tubes I am speaking of use a cold chemical getter inside a glass cartridge which is broken open during the final exhaust steps of manufacturing. Heat has no affect on the getter in them. Also, we use some large Eimac tubes like 4CW100,000D and 4CW250,000B and these have what I believe is a zirc getter 'flap' or 'hat' mounted along the filament mount, which is heated only by the filament power. On these tubes, it is best to allow 15 minutes of filament only, no HV, when they have been sitting a while. Again, the getter works best with only filament heat and full power doesn't enhance it. Zirconium getters best at about 1000 degrees C, this why large metal anode transmitting tubes like the 4-400A, 4-1000A, and 3-500 must be operated with a dull red to red anode color. Zirconium also releases some gasses and absorbs other gasses at various temperatures. The varying temperature across the length of the anode (and as the anode heats and cools) allows the gettering agent to absorb a wide variety of gasses. 73 John K5PRO Thermionic device user with a variety of industrial, scientific and broadcast applications. __ 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] Re: Screen Modulated 813
Lary - I was talking about the kind of set-up with the 6DE7 that produces a SMALL carrier of say 6 or 8 watts and then does 90 watts p.e.p. on the voice peaks. I may be nuts, but my empirical sense tells me that is far more impressive sounding in the receiver n the other end than the signal from the typical novice rig that runs 75 watts carrier input with Heising mod. OR even a plate modulated class C rig with 22.5 watts carrier input and 90 watts p.e.p. The power is turned DOWN during the inefficient phase of the transmission in other words. WIth less and less quiescent signal the transmitter appraoches the efficiency level of a DSB rig. Bry Carling writes: DX-60 followed by an 813 RF linear or SB200. Versus: 813 screen modulated final using the same method that sets the quiescent carrier level at about 10% of peak signal. Which would be more efficient? It's my understanding that from a 1st order analysis (ignoring subtleties like what plate voltage they are being run at, any differences in efficiencies between the tube types, output network design, etc, etc.), the plate efficiencies would theoretically be the same between a screen-modulated stage and a class AB linear amplifier stage amplifying an AM signal, since they are both essentially efficiency modulation techniques. 73., -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
[AMRadio] AM 813s X 813s
Hello All, Take a look at W3BYM's pair of 813s modulating a pair of 813s. A VERY robust, well designed, engineered, AND FINE sounding Homebrew! My recommendation would be to get the back issues. The price of back issues is $3.75 ea. The specific issues are: Number 153 - February 2002 Number 154 - March 2002 Number 155 - April 2002 The text goes into design considerations, parts selection, specific transformer information/identification, and tap selection. Also issues as to modification of the BW 850A bandswitch/coil assembly. -- Bob - NØDGN +--+ | \\//CraftyBob - WitchDoctor \\// | | (@ @) Bob Bethman - NØDGN(@ @) | +---oOOo-(_)-oOOo--oOOo-(_)-oOOo---+ | NØDGN AMRadio Manassas, VA|REAL Tube Radio and AM| +---+--+ | Manassas Radio - Home of Homemade Kielbasa Pirogi| +---+--+ | Bob Bethman\\\|/// The absence of a danger | | rbethman(at)comcast.net \\ ~ ~ // signal does *NOT* mean | | (/ @ @ /) that everything is OK | +-oOOo-(_)-oOOo+ | http://home.comcast.net/~rbethman| | 1 BC-61ØI w/BC-614I,1 T-213/GRC-26 w/BC614I,1 '51 Collins R-39ØA | | SP-6ØØ/NR Type 159, Heath DX-6Ø, Apache, Mohawk, SX-1Ø1, HT-32A | +---.oooO---Oooo.---.oooO---Oooo.--+ | () ()Opinions expressed are that() () | |\ ( ) /of my own and do not \ ( ) / | | \_ ) ( _/represent those of ANYONE else \_ ) ( _/| +--+ | Amateur Astronomer - Celestron Nexstar 8 Meade ETX-6Ø | | 38 Deg 46'48.62' N - 77 Deg 28'26.89 W | +--.oooO---Oooo.---+ | () () | | \ ( ) /| |\_ ) ( _/ | |ALL E-mail received and sent scanned by AVG | +--+ __ 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] Lettering or decals for BC 610
Bill, Howard Mills has the entire front panel silk screen and has it screened done by a professional.. He also repaints the panel and the case if you wish in wrinkle black. His email is [EMAIL PROTECTED] or phone at 304-876-6483. -73- Peter K2LRC Bill Fondren wrote: I think I sent this question to the wrong email addressNo telling where it went Anyway I will send it again. I just got an old BC 610 on the air. I need to paint the unit No problem with painting it, but what is the best way to get the lettering or decals on the front panel. I went to our local sign shop and the lady warned me that the computer cut letters that small would not be to good. She tried and she was correct. She said she could have the letters printed on a clear stickon sheet, something like stotch tape I guess. Has anyone tried any of the decal kits available on the internet. Found some kits that are called water slide decals, but white letters take a special kit. Hope some one out there has a good solution Bill K5PML __ 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
[AMRadio] AM 813s X 813s Clarification - ER Magazine
Hello All, Take a look at W3BYM's pair of 813s modulating a pair of 813s. A VERY robust, well designed, engineered, AND FINE sounding Homebrew! The entirety is available in Electric Radio Magazine http://www.ermag.com/ My recommendation would be to get the ER back issues. The price of back issues is $3.75 ea. The specific issues are: Number 153 - February 2002 Number 154 - March 2002 Number 155 - April 2002 The text goes into design considerations, parts selection, specific transformer information/identification, and tap selection. Also issues as to modification of the BW 850A bandswitch/coil assembly. -- Bob - NØDGN +--+ | \\//CraftyBob - WitchDoctor \\// | | (@ @) Bob Bethman - NØDGN(@ @) | +---oOOo-(_)-oOOo--oOOo-(_)-oOOo---+ | NØDGN AMRadio Manassas, VA|REAL Tube Radio and AM| +---+--+ | Manassas Radio - Home of Homemade Kielbasa Pirogi| +---+--+ | Bob Bethman\\\|/// The absence of a danger | | rbethman(at)comcast.net \\ ~ ~ // signal does *NOT* mean | | (/ @ @ /) that everything is OK | +-oOOo-(_)-oOOo+ | http://home.comcast.net/~rbethman| | 1 BC-61ØI w/BC-614I,1 T-213/GRC-26 w/BC614I,1 '51 Collins R-39ØA | | SP-6ØØ/NR Type 159, Heath DX-6Ø, Apache, Mohawk, SX-1Ø1, HT-32A | +---.oooO---Oooo.---.oooO---Oooo.--+ | () ()Opinions expressed are that() () | |\ ( ) /of my own and do not \ ( ) / | | \_ ) ( _/represent those of ANYONE else \_ ) ( _/| +--+ | Amateur Astronomer - Celestron Nexstar 8 Meade ETX-6Ø | | 38 Deg 46'48.62' N - 77 Deg 28'26.89 W | +--.oooO---Oooo.---+ | () () | | \ ( ) /| |\_ ) ( _/ | |ALL E-mail received and sent scanned by AVG | +--+ __ 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] Antenna's..
Hi Brett, I sent this as reply all I guess, my apologies to the net, but since it's started, let's finish it up here in case anyone can add some input to our musings. Please let me, if not us know your experiances with the A - D Multi Bander. I just had another thought. I tried that antenna on the recomendations of a buddy in Southern Oregon. He said it worked like a charm. A local fellow had the same experiance I had with it. I think it may have something to do with the type of ground it is OVER, along with hight, dipole or V, etc... No expert here, but when I talk to folks that are in much more damp environs than us here in dry central California, they confirm much better S/N ratios and ease of tuning out of resonance wire antennas. Then again I may be all wet (no pun intended). 73 Craig K6QI Brett gazdzinski [EMAIL PROTECTED] wrote: Yes, I think it can get to the point where its important, say if you run 700 watts of carrier power and make long transmissions Now open wire line does not have that problem, but you need a balanced tuner. Shielding a balanced tuner that is good for 700 watts of carrier, and making it easy to jump between 160 and 10 meters seems a bit tough to do. Using an unbalanced tuner on a non resonant antenna at high power does not seem to work very well, the tuner might be fine, but losses in the coax are high, in other places you might be at a high voltage point and have arcing the tuner. That is why I might try the alpha delta, its not going to work great on 160, only fair on 80, but it should be able to be made resonant enough to allow a tuner or no tuner operation. At least, that is what THEY say... Brett N2DTS -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Craig Carter Sent: Monday, December 11, 2006 1:36 PM To: Discussion of AM Radio in the Amateur Service Subject: RE: Re: [AMRadio] Antenna's.. Hi Brett, OK, I've never run one before, this is my first 'multi' band. But I'll clue you on what I found... I've got one half of the dipole at about level. The other side drops down... not like an inverted V, but a slight slope. The slope side also has a slight dogleg. The entire antenna is more of an L than a dipole, and I think it ended up at about 123' 9. It is made with insulated stranded #14 copper clad steel wire. (no stretching) Since I knew it would be WAY out of resonance, I used real porcelain end insulators and a one foot glass insulator in the middle. I didn't want to be melting any insulators while on AM. I use RG 8 coax. On AM, if I use one of my Apache's or a DX-100 there are no coax cooking or heating problems. I am nearly finished restoring a home brew 813 modulated by a pair of 811's. While doing full power on the air tests the coax gets warm on the bands above 40 meters --- that's not good. But I don't have time to do anything about it yet. I imagine I'll have to switch the garage shack (where the home brew is) to open wire feeder, but??? My modern rigs, Icom's, or vintage SSB gear doesn't even begin to heat up the coax on SSB or CW, even if I use my ancient Warrior amp. I've never checked it on PSK, but I doubt it would get hot. I use the 2060 and have to admit, it's a great tuner. It is kind of a pain having another stage to tune, but the antenna sure works great for everything from chewin the rag local on 75 and 160 to DX. 73 Merry Christmas Craig K6QI At 05:40 AM 12/11/2006, you wrote: Craig, Thanks for the info. What power do you run? I might be able to get 110 feet, maybe a little more if I put the wire in the tree branches...insulated wire? I have found that the RG214 coax can get real hot if I run into an antenna that is not resonant... I have the heath 2060a, although I hate to use it. Brett N2DTS -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Craig Carter Sent: Friday, December 08, 2006 11:33 PM To: Discussion of AM Radio in the Amateur Service Subject: RE: Re: [AMRadio] Antenna's.. I had one of the Alpha Delta 40 80 and a multi band Alpha Delta dipoles. With a tuner, the multi band was one of the best dummy loads I've ever had. The 80 / 40 trapless dipole was 'eh' on 80, ok on 40. I now have a 125' dipole, bent all over he!! and gone, and a Heath SA 2060 tuner with RG 8. Works great on every band I try it on, including 6 and 2! I would put up the longest wire I could fit, get a BAT (big 'butted' tuner) and have fun. 73 Craig K6QI __ 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] Screen Modulated 813
You can use a series resistance in the lead from the heising modulator reactor to the screen or plate bypassed with a capacitor to pass the audio and you get reduced carries and more audio punch. Healthfully yours, Don W4BWS - Original Message - From: Bry Carling [EMAIL PROTECTED] To: Discussion of AM Radio in the Amateur Service amradio@mailman.qth.net Sent: Monday, December 11, 2006 8:09 AM Subject: RE: [AMRadio] Screen Modulated 813 One major advantage with some of these schemes is to run AM with reduced carrier. Heath does it with their DX60 and others. You can run that screen mod scheme in the final OR you can run it a lower level and follow that with a linear amplifier. I would defer to the RF engineering experts here as to which is the better method. Yes, I would love to read an comparative assessment of the two methods. DX-60 followed by an 813 RF linear or SB200. Versus: 813 screen modulated final using the same method that sets the quiescent carrier level at about 10% of peak signal. Which would be more efficient? I know it is just a personal preference, but I happen to think that the Heath screen mod method for reduced carrier sounds great and carries a lot of punch on the air. I have read that the Heising choke modulation method will only get the signal to be 85% modulated, which is not at all bad. It just means you have a nice fat carrier (unlike the reduced carrier methods) and a little more carrier than with plate modulation What say the transmitter design aficionados out there? 73 de AF4K, Bry I understand the efficiency problems but isn't this sort of academic when talking about a max 300 w carrier? Won't two 813's produce that much even when run inefficiently? Surely it would be an improvement over using the Heath SB200 and the Ranger... no? Any thoughts? js Jack, Screen modulation is another form of efficiency modulation that will behave a lot like an AM linear amplifier in terms of capability for a given tube. Your SB-200 has 2 X 160 watts of dissipation available, and the dual 813 has 2 X 125 watts dissipation available. IMHO the 813 in ICAS rating is more conservatively rated than the 572B, so I'd think this is a wash between the two. I have a Central electronics 600L linear amplifier with a grid driven single 813 in class Ab2. On AM the single 813 is happy at 70 watts RF out, but it will do 100 watts AM and modulate upward 100%. It does blush a little but as long as I talk the red stays away. The drive need is under 5 watts too with that 813. Screen modulation, although relatively simple, requires the screen audio drive to stay linear when the screen current varies from zero to fairly high level. This means the screen modulator needs to have a low source impedance, and some inverse feedback is helpful. One approach is to use something like a triode connected beam power tube as a cathode follower to drive the screen. You can also use a low power ( 10 watts or so ) modulator circuit with a small modulation transformer for the 813 screen. Regards, Jim JKO -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.432 / Virus Database: 268.15.15/581 - Release Date: 12/9/2006 3:41 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 __ 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] Lettering or decal for BC 610
I've seen some good deals on p-touch machines and labels at buy.com Steve WD8DAS __ 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] Antenna's..
Group, I've got one of the Multi-Band Alpha Delta's up, and have had for about 8+ years. For my Apache it is fine, it receives DARN good on my R-390A and SP-600. I've even gotten 6mtr on it with the SP-600. NO tuner. I've run my TS-930 SAT, my DX-60 with an Amp Supply LK-500Z, AND my BC-610 and T-213. The ONLY problem that has cropped up is the BC-610 T-213. Neither of them wants ANYTHING to do with the inductor in the 80/40 element. It is NOT a trap! I suppose if it was a trap, those old Beasts MIGHT work with it too! QSOs from here in Virginia to NY, PA, NJ, SC, NC, FL, MI. Bob - N0DGN Craig Carter wrote: Hi Brett, I sent this as reply all I guess, my apologies to the net, but since it's started, let's finish it up here in case anyone can add some input to our musings. Please let me, if not us know your experiances with the A - D Multi Bander. I just had another thought. I tried that antenna on the recomendations of a buddy in Southern Oregon. He said it worked like a charm. A local fellow had the same experiance I had with it. I think it may have something to do with the type of ground it is OVER, along with hight, dipole or V, etc... No expert here, but when I talk to folks that are in much more damp environs than us here in dry central California, they confirm much better S/N ratios and ease of tuning out of resonance wire antennas. Then again I may be all wet (no pun intended). 73 Craig K6QI snip That is why I might try the alpha delta, its not going to work great on 160, only fair on 80, but it should be able to be made resonant enough to allow a tuner or no tuner operation. At least, that is what THEY say... Brett N2DTS Bob - N0DGN -- Bob - NØDGN +--+ | \\//CraftyBob - WitchDoctor \\// | | (@ @) Bob Bethman - NØDGN(@ @) | +---oOOo-(_)-oOOo--oOOo-(_)-oOOo---+ | NØDGN AMRadio Manassas, VA|REAL Tube Radio and AM| +---+--+ | Manassas Radio - Home of Homemade Kielbasa Pirogi| +---+--+ | Bob Bethman\\\|/// The absence of a danger | | rbethman(at)comcast.net \\ ~ ~ // signal does *NOT* mean | | (/ @ @ /) that everything is OK | +-oOOo-(_)-oOOo+ | http://home.comcast.net/~rbethman| | 1 BC-61ØI w/BC-614I,1 T-213/GRC-26 w/BC614I,1 '51 Collins R-39ØA | | SP-6ØØ/NR Type 159, Heath DX-6Ø, Apache, Mohawk, SX-1Ø1, HT-32A | +---.oooO---Oooo.---.oooO---Oooo.--+ | () ()Opinions expressed are that() () | |\ ( ) /of my own and do not \ ( ) / | | \_ ) ( _/represent those of ANYONE else \_ ) ( _/| +--+ | Amateur Astronomer - Celestron Nexstar 8 Meade ETX-6Ø | | 38 Deg 46'48.62' N - 77 Deg 28'26.89 W | +--.oooO---Oooo.---+ | () () | | \ ( ) /| |\_ ) ( _/ | |ALL E-mail received and sent scanned by AVG | +--+ __ 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] Component ID please
John E. Coleman (ARS WA5BXO) wrote: So perhaps the other device was another resistor to adjust the value so that the meter is more accurate than it was with just the one resistor. Well, the bands are black (background yellow) blue. Which would be 17 meg but it is also open and it is unlikely that both a comp res and a wirewound would be open. So I presume it is a cap and if you say one is not necessary, I will just replace the 500k and call it fixed. There is also a 5 meg from the hv to the meter. Thanks, 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] Screen Modulated 813
[EMAIL PROTECTED] writes: Most 813's had graphite plates, and I never remember them showing color, I always thought that would be way beyond what they were good for, or was good for them...if they were glowing! I was testing my single-813 grounded-grid amp the other day and had it making 500 watts out cw. The plate was a bit red at peak output, but getting very red fast off the peak of the tuning. Steve WD8DAS __ 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] AM 813s X 813s
Rbethman wrote: Hello All, Take a look at W3BYM's pair of 813s modulating a pair of 813s. A VERY robust, well designed, engineered, AND FINE sounding Homebrew! My recommendation would be to get the back issues. The price of back issues is $3.75 ea. The specific issues are: Number 153 - February 2002 Number 154 - March 2002 Number 155 - April 2002 Most amazing! The mailman brought me those issues today and I didn't get much of a nap while reading them. I was most interested in the power supply but very little was said about it and the schematic was incomplete. As a point of interest, not realizing it was the same thing, I down loaded the same article for free about the same time I ordered the back issues. http://www.wb4gwa.netfirms.com/pagethree.html 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] Component ID please
Jack, Check the meter with another meter and see if it is reading 1ma and is accurate enough. You can series up a DMM with the movement coil and a resistor of a few thousand ohms and put a 5V in to the whole series circuit to see if you're DMM and the meter movement under test is reading the same. If it is accurate and is indeed a 1 ma movement then just forget the parts in the meter (connect the movement direct to the terminals) and connect the meter to the external 5 meg resistor. In this lash up, the 5 meg resistor will supply 1ma to the meter, when there is 5KV present, and the meter will read 500. Good Luck John, WA5BXO -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Jack Schmidling Sent: Monday, December 11, 2006 5:32 PM To: Discussion of AM Radio in the Amateur Service Subject: Re: [AMRadio] Component ID please John E. Coleman (ARS WA5BXO) wrote: So perhaps the other device was another resistor to adjust the value so that the meter is more accurate than it was with just the one resistor. Well, the bands are black (background yellow) blue. Which would be 17 meg but it is also open and it is unlikely that both a comp res and a wirewound would be open. So I presume it is a cap and if you say one is not necessary, I will just replace the 500k and call it fixed. There is also a 5 meg from the hv to the meter. Thanks, 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] Screen Modulated 813
[EMAIL PROTECTED] wrote: [EMAIL PROTECTED] writes: Most 813's had graphite plates, and I never remember them showing color, I always thought that would be way beyond what they were good for, or was good for them...if they were glowing! I was testing my single-813 grounded-grid amp the other day and had it making 500 watts out cw. The plate was a bit red at peak output, but getting very red fast off the peak of the tuning. You probably saw a rise in plate current, as well. Off-resonance. I've had 250TH's in my rig (balanced, cross-neutralized, link-coupled) and had one show color, while the other did not. Different brands of tubes.. different plate configurations... differences all over. but, they still dipped at the same place, and drew the same amount of current off-resonance, and drew different shades of red, depending on which tube you look at. -- 73 __ 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] ARRL asks for modification of 80 meter plan
FYI, This was posted on the ARRL site today, see http://www.arrl.org/news/stories/2006/12/11/100/?nc=1 K5XU League Asks FCC to Postpone, Modify Part of 75-Meter Band Change NEWINGTON, CT, Dec 11, 2006 -- In separate petitions today, the ARRL asked the FCC to postpone the change in allocation for 3600 to 3635 kHz while it considers a request to maintain the status quo in the segment. The so-called omnibus Report and Order (RO) in WT Docket 04-140, which included moving the lower edge of the Amateur Extra 75-meter phone band to 3600 kHz, is set to go into effect Friday, December 15. The League wants the Commission to rectify the unintended consequence of the expansion by moving the dividing line between the narrowband and wideband segments of 80/75 meters to 3635 kHz. This would keep 3600 to 3635 kHz available to General and higher licensees for RTTY, data and CW and open to Novice and Tech Plus licensees for CW. The requested change also would maintain access to the automatically controlled digital subband, 3620 to 3635 kHz. In a Petition for Reconsideration, the League emphasized that it was not seeking reconsideration of the entire 75-meter phone band expansion. Rather, we ask only that the Commission restore the privileges unintentionally withdrawn from those who operate and who utilize automatically controlled narrowband digital stations between 3620 and 3635 kHz, the League said. The ARRL pointed out that while the RO left unchanged rules permitting automatically controlled narrowband digital in that segment, it eliminated RTTY and data as permitted emissions above 3600 kHz. The ARRL also filed a Petition for Partial Stay of Effective Date of Rule pending final action on its reconsideration petition. To justify its far greater-than-requested expansion, the League asserted, the FCC relied on the flawed logic of a handful of commenters who specifically asked for a 3600 to 4000 kHz phone band. Some commenters had made the case during the proceeding that the CW subband is vastly underutilized while space for SSB is at a premium. It affects considerably more than just those two operating modes, the ARRL said of the expansion. Narrowband RTTY and data modes are increasingly used at 80 meters as well, and substantial numbers of RTTY and data users stand to be displaced, as well as precluded entirely, by the extent of the telephony subband expansion there. The League contends the FCC contradicted itself by saying the rule revisions wouldn't result in any licensee losing spectrum privileges. But operating privileges have been lost by the extent of the expansion at 80 meters, the reconsideration petition states. The expansion also significantly burdens and adversely impacts CW nets above 3600 kHz -- including emergency and public service nets -- most, if not all, of which will have to cease operating or change frequency, the League added. Most important, however, is the loss of spectrum for automatically controlled digital modes. The ARRL petition cites the comments of several League members decrying the loss of spectrum for PACTOR, CW and RTTY. The Winlink 2000 system was cited as a best practice by several post-Hurricane Katrina reviews, including the Congressional 'Failure of Initiative' report, remarked ARRL South Texas Section Emergency Coordinator Jerry Reimer, KK5CA. The ARRL says shifting the band edge slightly upward would provide a simple and equitable fix to the obvious error in the RO. This is neither a minor matter nor an academic exercise in future band planning, the ARRL concluded. It is an urgent problem which, unless corrected, affects a substantial number of existing Amateur Radio fixed facilities and an even more substantial number of mobile facilities. __ 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] ARRL asks for modification of 80 meter plan
Sore losers aren't they. Want more digital and CW. I am surprised they waited this long. Jim W5JO FYI, This was posted on the ARRL site today, see http://www.arrl.org/news/stories/2006/12/11/100/?nc=1 K5XU League Asks FCC to Postpone, Modify Part of 75-Meter Band Change __ 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] Component ID please
John E. Coleman (ARS WA5BXO) wrote: Jack, Check the meter with another meter and see if it is reading 1ma and is accurate enough. Actually, with the new 500k in the meter, it reads 10v with 10v in. Couldn't think of anything with a higher DC voltage to calibrate with but at least is is functioning and in the ball park. 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] ARRL asks for modification of 80 meter plan
naw, it took them this long to find an excuse. CW is dead and the digital modes are only used by a very few. They can move just like we can. John N1fcu --- Jim Wilhite [EMAIL PROTECTED] wrote: Sore losers aren't they. Want more digital and CW. I am surprised they waited this long. Jim W5JO FYI, This was posted on the ARRL site today, see http://www.arrl.org/news/stories/2006/12/11/100/?nc=1 K5XU League Asks FCC to Postpone, Modify Part of 75-Meter Band Change __ 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 Any questions? Get answers on any topic at www.Answers.yahoo.com. Try it now. Cheap talk? Check out Yahoo! Messenger's low PC-to-Phone call rates. http://voice.yahoo.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] BW Capacitors
Bless their heart, someone on here, a while back, sent me a catalog from BW and their Air Variable Butterfly capacitors. The list had the different butterfly capacitors (namely, the CX series) and I can't find that thing around here to save my soul. If anyone has a listing of the caps, and their values, would they please list them? Specifically, the CX-77, and CX-82. AdvTHANKSance -- -Geoff/W5OMR __ 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] Multi-Elmac PS-2 Power Supply Schematic
Does anyone have a PS-2 or M-1070 power supply schematic which is used on the AF-67? I can't find mine, and trying to rebuild one for a friend. Joe W4AAB __ 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] Component ID please
Well then that proves that the movement is indeed a 1ma movement. Now you need to remove the 500K ohm if you are going to be using it with an external 5Meg else you will be 10 percent off in measurments. You could also leave the 500K inside, and replace the external 5 meg with a 4.5 meg. The total resistance needs to be 5 meg to use a multiplier of 10 on the scale. If you leave the total resistance a 5.5 meg (5 meg +500K) then you will need to multiply the meter reading by 11 instead of just 10. That's too difficult. If you want a full scale reading of 2KV (multiply the scale by 4) then the total resistance should be 2 MEG. John -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Jack Schmidling Sent: Monday, December 11, 2006 9:55 PM To: Discussion of AM Radio in the Amateur Service Subject: Re: [AMRadio] Component ID please John E. Coleman (ARS WA5BXO) wrote: Jack, Check the meter with another meter and see if it is reading 1ma and is accurate enough. Actually, with the new 500k in the meter, it reads 10v with 10v in. Couldn't think of anything with a higher DC voltage to calibrate with but at least is is functioning and in the ball park. 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] Step Start
John E. Coleman (ARS WA5BXO) wrote: Jack I would dispense with the startup circuit. With the choke input filter system and only 4mf of output capacitance you want need a start up circuit. It's a total of 8 mf for the record but I am now thinking that the hi/low switch was for low power tune up and had nothing to do with start up. I have it rewired now for 110 and have a light bulb simulating the xformer and notice a quirk with the time delay. The contactor clacks on after 60 seconds but if I shut if off I have to wait some period of time before it will time out at 60 seconds because of the latent heat. Seems like it is only good for initial turn on. I got bored trying to figure out how long it takes to cool down. One more thing, the 866's have strange flakes of some sort of metal that adhere to the inside of the tube and I can't seem to shake them down. They kling to the glass as like from static electricity. Should I be concerned about these and not use them? 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] Component ID please
John Coleman ARS WA5BXO wrote: Well then that proves that the movement is indeed a 1ma movement. Now you need to remove the 500K ohm if you are going to be using it with an external 5Meg else you will be 10 percent off in measurments. You could also leave the 500K inside, and replace the external 5 meg with a 4.5 meg. Well that is strange as I was only guessing at the 5 meg. According to my notes it is 5.6 and is already in there and presumed to work with the 500k in the meter. Something's not right here. I may have read the 5.6 incorrectly and will check it again tomorrow. However, the absolute value does not seem all that important to me. It's just an indicator that things are normal. I can measure the voltage directly and note where that is on the meter and extrapolate from there if/when things change. I'm pretty easy to please. I guess you can translate that to lazy. Thanks, 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] Multi-Elmac PS-2 Power Supply Schematic
The M1070 and PS2 manuals are both on the BAMA website. Al Tyson WB6HPF __ 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
