[AMRadio] Loading antenna with BC 610 E
I am thrilled to report that I have my RRd BC 610 E putting out lots of RF (about 370 watts) into a 50 ohm Cantenna dummy load. I am experiencing some slight spitting and arcing at built in antenna relay. I speculate that that spitting is due to inadequate loading or RF transfer from the final tank coil to the dummy load. I am feeding the dummy load directly through coax connected to the two feed through insulators on the output. I would appreciate recommendations regarding a loading device to help transfer RF from the tank coil to the antenna. Will installing a C2 from output to ground tune the reactance out of the feed line and facilitate loading the dummy load better or loading the Coax feedline to the antenna?? I would appreciate the benefit of your actual experience or knowledge to assist me in interfacing this BC 610 E to a feedline. Thanks and 73, John, K5PGW Never miss a thing. Make Yahoo your home page. http://www.yahoo.com/r/hs __ Our Main Website: http://www.amfone.net AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
Re: [AMRadio] Loading antenna with BC 610 E
- Original Message - Subject: [AMRadio] Loading antenna with BC 610 E Date: Thu, January 17, 2008 11:32 From: John King [EMAIL PROTECTED] I would appreciate recommendations regarding a loading device to help transfer RF from the tank coil to the antenna. Will installing a C2 from output to ground tune the reactance out of the feed line and facilitate loading the dummy load better or loading the Coax feedline to the antenna?? Hi John, I believe what you want to do is put a variable capacitance in series with the output link to resonate it. This should be connected such that the rotor of the capacitor is grounded/connected to the coax braid, and the stator connects to one end of the link. The coax center conductor gets connected to the opposite end of the link. About 1200pF maximum should be adequate for all bands except 160M. If you operate 160M you can put a large 1000pF transmitting mica in parallel with the variable capacitor when you operate there. I don't have experience with an actual BC-610, but know folks that do, and use the above method (W1CKI, for one). Also, I have a homebrew rig that operates up to 300W output and uses BC-610 coils with the above method. I use the three-section ganged air variable from a late 1920s-era TRF broadcast radio. The spacing between rotor stator seems adequate for this power level with this vintage capacitor. More modern broadcast air variables may not be. All three stators, ~400pF each, are connected in parallel. GL, -Larry/NE1S __ Our Main Website: http://www.amfone.net AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
[AMRadio] Home-brewing construction considerations
In a balanced push-pull Class C RF Final with plug-in coils, I've seen things done a couple of different ways. One is, to split the B+ so that the potential is fed with the BW HDVL jack-bar to the inside of the two coil's. The outside of the coils is then connected to the tubes. That's the way the home-brewed 250TH final I'm running was done, back in the mid '50's. There was also a couple of finger-stock pieces across the BW butterfly tuning condenser to facilitate adding a vaccuum capacitor across it for allowing the circuit to resonate on a lower frequency (like 75, or 160m). I understand that the circuit would no longer be 'balanced' were that condition to occur. It would go back to being balanced if a pair of capacitors at half the required value were used, and where the two meet in the middle were tied to the stator of the Butterfly. THAT would keep it balanced. That's the reason for the split-stator capacitor across the final, now. But, that's not my question... I recently picked up another home-brew 250TH final that has had more RFI considerations involved in it's construction (than the one in current operation) as it was built sometime in the '60's. Screen and mesh aluminum, etc... It's nice and hopefully will keep me out of the neighbors TV's, microwaves, blenders, etc... (grin) But the plug in coil is what prompted me to this question: Is there a difference in feeding each of the inside sockets on the jack-bar with B+ from the top of the RF plate choke, vs having the two coils tied together, in the middle, and feeding B+ there? I understand that the potential is the same, but for the sake of having less stray capacitance and a 'cleaner' RF environment, which would be better, and please... tell me why? Thanks! -- 73 = Best Regards, -Geoff/W5OMR __ Our Main Website: http://www.amfone.net AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
RE: [AMRadio] Home-brewing construction considerations
Hi Geoff: In my opinion, the coils should be tied together in the middle as close to the coils as possible, either on the male bar or on the female bar. RF current flows on the wires between the coils so it is imperative that the wire be capable of handling the skin effect and current of the RF which is much greater than the DC/audio connection from the top of the RF choke. So rather than making two connections to the RF choke, where you would need to make large wire and have RF flowing though it, just make one connection with flexible wire and join the coils together at the coils. John, WA5BXO -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of geoff Sent: Thursday, January 17, 2008 11:49 AM To: Discussion of AM Radio in the Amateur Service Subject: [AMRadio] Home-brewing construction considerations In a balanced push-pull Class C RF Final with plug-in coils, I've seen things done a couple of different ways. One is, to split the B+ so that the potential is fed with the BW HDVL jack-bar to the inside of the two coil's. The outside of the coils is then connected to the tubes. That's the way the home-brewed 250TH final I'm running was done, back in the mid '50's. There was also a couple of finger-stock pieces across the BW butterfly tuning condenser to facilitate adding a vaccuum capacitor across it for allowing the circuit to resonate on a lower frequency (like 75, or 160m). I understand that the circuit would no longer be 'balanced' were that condition to occur. It would go back to being balanced if a pair of capacitors at half the required value were used, and where the two meet in the middle were tied to the stator of the Butterfly. THAT would keep it balanced. That's the reason for the split-stator capacitor across the final, now. But, that's not my question... I recently picked up another home-brew 250TH final that has had more RFI considerations involved in it's construction (than the one in current operation) as it was built sometime in the '60's. Screen and mesh aluminum, etc... It's nice and hopefully will keep me out of the neighbors TV's, microwaves, blenders, etc... (grin) But the plug in coil is what prompted me to this question: Is there a difference in feeding each of the inside sockets on the jack-bar with B+ from the top of the RF plate choke, vs having the two coils tied together, in the middle, and feeding B+ there? I understand that the potential is the same, but for the sake of having less stray capacitance and a 'cleaner' RF environment, which would be better, and please... tell me why? Thanks! -- 73 = Best Regards, -Geoff/W5OMR __ Our Main Website: http://www.amfone.net AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body. __ Our Main Website: http://www.amfone.net AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
Re: [AMRadio] Home-brewing construction considerations
John Coleman wrote: Hi Geoff: In my opinion, the coils should be tied together in the middle as close to the coils as possible, either on the male bar or on the female bar. RF current flows on the wires between the coils so it is imperative that the wire be capable of handling the skin effect and current of the RF which is much greater than the DC/audio connection from the top of the RF choke. So rather than making two connections to the RF choke, where you would need to make large wire and have RF flowing though it, just make one connection with flexible wire and join the coils together at the coils. So, just to be crystal clear, a piece of wire between the coil halves -on the coil assembly itself- would be better. I could just add another pin in the middle of the coil assembly then add a socket which would be connected directly to the top of the RF choke. Thanks, John. Hopefully, one of these days, the 'moderation bit' will be lifted off my AM Reflector account, and mail will get to the list a bit quicker. -- 73 = Best Regards, -Geoff/W5OMR __ Our Main Website: http://www.amfone.net AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
Re: [AMRadio] Home-brewing construction considerations
- Original Message - Subject: [AMRadio] Home-brewing construction considerations Date: Thu, January 17, 2008 12:49 From: geoff [EMAIL PROTECTED] In a balanced push-pull Class C RF Final with plug-in coils, I've seen things done a couple of different ways. One is, to split the B+ so that the potential is fed with the Bamp;W HDVL jack-bar to the inside of the two coil's. The outside of the coils is then connected to the tubes. That's the way the home-brewed 250TH final I'm running was done, back in the mid '50's. There was also a couple of finger-stock pieces across the Bamp;W butterfly tuning condenser to facilitate adding a vaccuum capacitor across it for allowing the circuit to resonate on a lower frequency (like 75, or 160m). I understand that the circuit would no longer be 'balanced' were that condition to occur. It would go back to being balanced if a pair of capacitors at half the required value were used, and where the two meet in the middle were tied to the stator of the Butterfly. THAT would keep it balanced. That's the reason for the split-stator capacitor across the final, now. But, that's not my question... Hi Geoff, how ya' been? I understand it's not your question, but if I understand you correctly, I beg to differ on a few things you stated above: 1) A single capacitor plate-to-plate wound probably not upset the balance appreciably - in fact if the cap, and connections to it, were totally symmetric it wouldn't at all. The fixed vacuum caps I've seen have an outside and an inside cylinder, so stray capacitance to the surroundings from the outside cylinder would probably be larger than the strays to the inside cylinder. However, as long as the cap was reasonably spaced from surrounding stuff, I don't think it would be of any practical consequence on the lower bands where you'd be using the auxiliary fixed cap anyway. 2)If you were to use two caps, with a common connection tied to the rotor of the butterfly cap (you said stator - did you mean rotor?), their values would need to be double (not half) the value of a single cap, because they are effectively in series. -SNIP- Is there a difference in feeding each of the inside sockets on the jack-bar with B+ from the top of the RF plate choke, vs having the two coils tied together, in the middle, and feeding B+ there? I understand that the potential is the same, but for the sake of having less stray capacitance and a 'cleaner' RF environment, which would be better, and please... tell me why? Thanks! John already answered this, so I won't bother. Good luck with the new RF deck - are you replacing the old one, or completely different/new transmitter? 73, -Larry/NE1S __ Our Main Website: http://www.amfone.net AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
Re: [AMRadio] Manual
On Jan 17, 2008 2:50 PM, Rick [EMAIL PROTECTED] wrote: Would anyone on the list happen to have a manual for the HP-410B voltmeter? Mine went south on me recently and I'd like to get it up and running. I think there are copies available online for download, Rick. If you don't locate one, let me know and I'll check with Mike W1RC to see if he has any copies left. ~ Todd, KA1KAQ __ Our Main Website: http://www.amfone.net AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
[AMRadio] Re: AMRadio Digest, Vol 48, Issue 25 (posting replies)
That discussion should have been kept off the list Ed, sorry. I had hoped one of the two parties would have told us the mistake so we would know what was going on. This is like beating a dead horse for me, over and over again Advertise your stuff on the list, buy your stuff from the seller, but PLEASE do not use the list to conduct your transactions, shipping questions, etc. 400+ members do not need to know all that information. Remember, this is not an online web forum, it's an email list. Each and every message you post goes to someones email account. And PLEASE^2, when replying to a message, if you quote the original, snip out everything but what is relevant to the message at hand. Many of the posted messages quote the entire thread leading up to that message, headers and all. Out of self-defence, I use the Digest Mode, and sometimes it goes on page after page, a mixed mess, mostly previous messages quoted in their entirety. This makes it difficult to find and sort out the real messages and wastes far too much storage space on the server. It takes about 10 extra seconds to highlight and delete the irrelevant text. Don k4kyv __ Our Main Website: http://www.amfone.net AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
[AMRadio] Manual
Would anyone on the list happen to have a manual for the HP-410B voltmeter? Mine went south on me recently and I'd like to get it up and running. Thanks, Rick/K5IAR __ Our Main Website: http://www.amfone.net AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
Re: [AMRadio] Manual
I try to avoid BAMA if possible. Try this. http://manoman.sqhill.com/hp/index.htm 410B is 30.8 meg and I haven't downloaded it to know the quality. K7DFW ..._._ __ Our Main Website: http://www.amfone.net AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
Re: [AMRadio] Home-brewing construction considerations
Have you considered rebuilding for parallel operation and use a relay switched toroid input and a pi-net out? There are 6 band circuit boards available. It makes band changing a lot easier when the deck is shielded. Im converting a similar era deck that way. A further benefit is a coax fed antenna to further minimize stray RF radiation. There should be no problem getting to 15M with a standard air variable based upon the tube output C, the cap minimum and strays. I'll be using a vacuum variable and coverage will be 160-10M. With the tubes enclosed you will also need some fan assisted air exhausting. Have fun, 250TH decks seem to be everywhere lately. Carl KM1H - Original Message - From: geoff [EMAIL PROTECTED] To: Discussion of AM Radio in the Amateur Service amradio@mailman.qth.net Sent: Thursday, January 17, 2008 12:49 PM Subject: [AMRadio] Home-brewing construction considerations In a balanced push-pull Class C RF Final with plug-in coils, I've seen things done a couple of different ways. One is, to split the B+ so that the potential is fed with the BW HDVL jack-bar to the inside of the two coil's. The outside of the coils is then connected to the tubes. That's the way the home-brewed 250TH final I'm running was done, back in the mid '50's. There was also a couple of finger-stock pieces across the BW butterfly tuning condenser to facilitate adding a vaccuum capacitor across it for allowing the circuit to resonate on a lower frequency (like 75, or 160m). I understand that the circuit would no longer be 'balanced' were that condition to occur. It would go back to being balanced if a pair of capacitors at half the required value were used, and where the two meet in the middle were tied to the stator of the Butterfly. THAT would keep it balanced. That's the reason for the split-stator capacitor across the final, now. But, that's not my question... I recently picked up another home-brew 250TH final that has had more RFI considerations involved in it's construction (than the one in current operation) as it was built sometime in the '60's. Screen and mesh aluminum, etc... It's nice and hopefully will keep me out of the neighbors TV's, microwaves, blenders, etc... (grin) But the plug in coil is what prompted me to this question: Is there a difference in feeding each of the inside sockets on the jack-bar with B+ from the top of the RF plate choke, vs having the two coils tied together, in the middle, and feeding B+ there? I understand that the potential is the same, but for the sake of having less stray capacitance and a 'cleaner' RF environment, which would be better, and please... tell me why? Thanks! -- 73 = Best Regards, -Geoff/W5OMR __ Our Main Website: http://www.amfone.net AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body. __ Our Main Website: http://www.amfone.net AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
Re: [AMRadio] Manual
Bama has the 410B and the 410C. Bob - N0DGN On Jan 17, 2008 2:50 PM, Rick [EMAIL PROTECTED] wrote: Would anyone on the list happen to have a manual for the HP-410B voltmeter? Mine went south on me recently and I'd like to get it up and running. I think there are copies available online for download, Rick. If you don't locate one, let me know and I'll check with Mike W1RC to see if he has any copies left. ~ Todd, KA1KAQ __ Our Main Website: http://www.amfone.net AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
RE: [AMRadio] Manual
Thanks for all the replies. I got the manual from both BAMA and the manoman site. I must admit, the second site has a beautiful copy with all illustrations perfectly viewable as well as all pages neat and straight. Thanks again, guys.. Rick/K5IAR I try to avoid BAMA if possible. Try this. http://manoman.sqhill.com/hp/index.htm 410B is 30.8 meg and I haven't downloaded it to know the quality. K7DFW __ Our Main Website: http://www.amfone.net AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
[AMRadio] plug in coils for push pull
You could modify the assembly, but I don't think it is that critical. Just a good healthy strap at the socket works well. John, WA5BXO __ Our Main Website: http://www.amfone.net AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
RE: [AMRadio] Home-brewing construction considerations
Larry you are correct about the theory and if two capacitors are used they must be balanced also. I have generally found that balance is not always what it seems and if secondary single or double fixed capacitor can be avoided then that is best but it sometimes is not avoidable. And stray capacitance from a bad layout can really through you off. It is just one of those things that has to be dealt with on a individual basis. John, WA5BXO -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED] Sent: Thursday, January 17, 2008 1:41 PM To: Discussion of AM Radio in the Amateur Service Subject: Re: [AMRadio] Home-brewing construction considerations SNIP: 1) A single capacitor plate-to-plate wound probably not upset the balance appreciably - in fact if the cap, and connections to it, were totally symmetric it wouldn't at all. The fixed vacuum caps I've seen have an outside and an inside cylinder, so stray capacitance to the surroundings from the outside cylinder would probably be larger than the strays to the inside cylinder. However, as long as the cap was reasonably spaced from surrounding stuff, I don't think it would be of any practical consequence on the lower bands where you'd be using the auxiliary fixed cap anyway. 2)If you were to use two caps, with a common connection tied to the rotor of the butterfly cap (you said stator - did you mean rotor?), their values would need to be double (not half) the value of a single cap, because they are effectively in series. __ Our Main Website: http://www.amfone.net AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
Re: [AMRadio] Home-brewing construction considerations
[EMAIL PROTECTED] wrote: I understand that the circuit would no longer be 'balanced' were that condition to occur. It would go back to being balanced if a pair of capacitors at half the required value were used, and where the two meet in the middle were tied to the stator of the Butterfly. THAT would keep it balanced. That's the reason for the split-stator capacitor across the final, now. But, that's not my question... Hi Geoff, how ya' been? Having a ball playing radio, can ya tell? ;-) I understand it's not your question, but if I understand you correctly, I beg to differ on a few things you stated above: 1) A single capacitor plate-to-plate wound probably not upset the balance appreciably - in fact if the cap, and connections to it, were totally symmetric it wouldn't at all. The fixed vacuum caps I've seen have an outside and an inside cylinder, so stray capacitance to the surroundings from the outside cylinder would probably be larger than the strays to the inside cylinder. However, as long as the cap was reasonably spaced from surrounding stuff, I don't think it would be of any practical consequence on the lower bands where you'd be using the auxiliary fixed cap anyway. I wouldn't have thought so either if it had been anyone else who made that recommendation. But, it's hard to argue with a ham who's 'been there, done that' and has built up -many- kW rigs, always paying particular attention to minute details. If John/WA5BXO says it, I believe it. 2)If you were to use two caps, with a common connection tied to the rotor of the butterfly cap (you said stator - did you mean rotor?) No, I meant the part that doesn't rotate. The 'frame', if you will. , their values would need to be double (not half) the value of a single cap, because they are effectively in series. I want to add enough capacitance across each side of the butterfly, equally. I'm pretty sure I want half of the values. If (for example) the total capacitance that's used across the entire tuning capacitor is 50uuf, then each side has to be 25uuf, with the single mounting point on the frame of the capacitor... the part that doesn't rotate. Is it not called the 'stator'? Common sense tells me 'rotor' is the part that -moves- ;-) Good luck with the new RF deck - are you replacing the old one, or completely different/new transmitter? It'll be in addition to. I believe what I'm gonna do, is use the double-connected racks to house, 2 power supplies, the 250TH modulator and the original RF deck, on one side. 1 power supply the new RF deck, a 19 rack of (4) 6-position coax switches and an R-274 receiver on the other side. The coax switches will be used to select exciters and finals. With a totally adjustable bias supply for the new (to me) final, it would do fine in either Class B, for a linear (being driven by a rice-box), or Class C for high-level plate modulation, driven by the Viking II. I've still got a lot of thoughts in my head... this is just the preliminary thinking. Bottom line, I'm trying to conserve space in the shack. ;-) -- 73 __ Our Main Website: http://www.amfone.net AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
[AMRadio] Mit Romoney disses Ham Radio
I know it's not particularly pertinant to AM operations in Ham Radio, but it affects Ham radio, in general, and worth the read. We hams have it bad enough, when we try to get support for our hobby from those that regulate it. To have an aspiring politician (I don't care if he's running on the one-eyed, purple polka-dotted people eater ticket, he's still a politician) who's trying to become president of this nation, utter such a sentence, would certainly be a blow to ham-dom and the entire 'needed' community in case of a disaster. http://ema.arrl.org/article.php?sid=802 -- -Geoff/W5OMR __ Our Main Website: http://www.amfone.net AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
Re: [AMRadio] Loading antenna with BC 610 E
What my BC-610I has is an so239 mounted in the sidepanel just below the feed thrus. its connected to the feedthrus... i have a dowkey antenna relay hung off of it, and feed 375 watts out all day long into 50 ohms. I also pretune into a dummy load the same way. I use a tuner rated at 3k watts to tune 470 ohm feeders on a full wave loop on 75. using a 5kv 4 to 1 ballun to bring the coax into the shack. 73 warren w1gud On Jan 17, 2008, at 12:48 PM, [EMAIL PROTECTED] wrote: - Original Message - Subject: [AMRadio] Loading antenna with BC 610 E Date: Thu, January 17, 2008 11:32 From: John King [EMAIL PROTECTED] I would appreciate recommendations regarding a loading device to help transfer RF from the tank coil to the antenna. Will installing a C2 from output to ground tune the reactance out of the feed line and facilitate loading the dummy load better or loading the Coax feedline to the antenna?? Hi John, I believe what you want to do is put a variable capacitance in series with the output link to resonate it. This should be connected such that the rotor of the capacitor is grounded/connected to the coax braid, and the stator connects to one end of the link. The coax center conductor gets connected to the opposite end of the link. About 1200pF maximum should be adequate for all bands except 160M. If you operate 160M you can put a large 1000pF transmitting mica in parallel with the variable capacitor when you operate there. I don't have experience with an actual BC-610, but know folks that do, and use the above method (W1CKI, for one). Also, I have a homebrew rig that operates up to 300W output and uses BC-610 coils with the above method. I use the three-section ganged air variable from a late 1920s-era TRF broadcast radio. The spacing between rotor stator seems adequate for this power level with this vintage capacitor. More modern broadcast air variables may not be. All three stators, ~400pF each, are connected in parallel. GL, -Larry/NE1S __ Our Main Website: http://www.amfone.net AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body. __ Our Main Website: http://www.amfone.net AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
[AMRadio] T-368 FS on QTH
W5DPP has his T-368 for sale on QTH.com. Ad #641748. Usual disclaimers apply. Joe W4AAB __ Our Main Website: http://www.amfone.net AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
Re: [AMRadio] Mit Romoney disses Ham Radio
Read the date; old news; topic beat to death several years ago; heard he loves ham now. Pete, wa2cwa On Thu, 17 Jan 2008 16:57:41 -0600 geoff [EMAIL PROTECTED] writes: I know it's not particularly pertinant to AM operations in Ham Radio, but it affects Ham radio, in general, and worth the read. We hams have it bad enough, when we try to get support for our hobby from those that regulate it. To have an aspiring politician (I don't care if he's running on the one-eyed, purple polka-dotted people eater ticket, he's still a politician) who's trying to become president of this nation, utter such a sentence, would certainly be a blow to ham-dom and the entire 'needed' community in case of a disaster. http://ema.arrl.org/article.php?sid=802 -- -Geoff/W5OMR __ Our Main Website: http://www.amfone.net AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
Re: [AMRadio] Loading antenna with BC 610 E (Long-ish)
- Original Message - From: John King [EMAIL PROTECTED] To: amradio@mailman.qth.net Sent: Thursday, January 17, 2008 11:32 AM Subject: [AMRadio] Loading antenna with BC 610 E I am thrilled to report that I have my RRd BC 610 E putting out lots of RF (about 370 watts) into a 50 ohm Cantenna dummy load. Good show, but be advised, BC-610s are NOT regular transmitters! First off, the relay you are speaking of is NOT an antenna switching relay, it is a grounding relay for the output section of the plate coil, when the transmitter is in standby. when the transmitter is placed in transmit the relay un-shorts the link of the coil, which should already be connected to the dual insulators for open wire, and the SO-239 connector if you are using coax. I am experiencing some slight spitting and arcing at built in antenna relay. I speculate that that spitting is due to inadequate loading or RF transfer from the final tank coil to the dummy load. I am feeding the dummy load directly through coax connected to the two feed through insulators on the output. The E model had a MWO, that applied the SO-239 connector to the same plate that the two feed-thru insulators are mounted on. Check the schematic for proper connections, as the relay contacts should NOT have RF on them unless activated, Ie; in transmit mode, relay closes, and the short across the output link is removed. I would appreciate recommendations regarding a loading device to help transfer RF from the tank coil to the antenna. Will installing a C2 from output to ground tune the reactance out of the feed line and facilitate loading the dummy load better or loading the Coax feedline to the antenna?? In the manual, for all models, it says, with a load, either antenna, or dummy load connected to the proper terminals, (NOTE: when using coax ensure the shield goes to the chassis ground in/on the RF deck. As for loading into 50 ohms, first I must say the cantenna is fine for checking out smaller output radios, but again be advised the resistance of the dummy load changes as the temperature in the can goes up, they used to have on the side of the can a chart that could be related to the temperature, and then the actual resistance. for a true test, and this depends on what liquid you are using in the can, check the resistance of the load cold, then transmit into it for about 3 minutes, remove power and check the resistance again, with an accurate meter across the connector of the load, that will tell you what you are dealing with. For a reasonablely reliable load might I suggest the ME-165, which once calibrated holds true to accuracy if the instructions for it are followed. Also it is rated for 600W continuous for a period in the manual. If you want an antenna Switch might I suggest the E.F. Johnson TR-Switch? I use them here and have experienced no problems with their operation, except when I forget to turn down the audio from whatever receiver I am listening with! Feedback, is my punishment for forgetting, not into the receiver, out of the speaker from the receiver. Also as most of the BA type receivers have inputs ranging from 50 - 300 ohms, you can taylor the receiver connection on the unit to provide a better match to your receiver. As for power output, Both of the units I run (E I) models will provide 400 watts of carrier output into a dummy load. This requires some terms however, first the unit MUST be running properly, next the tubes should be of good quality, starting with the Oscillator and going to the PA output. One last word set it up JUST LIKE the manual says it will run forever, allowing for the vagarieties of older equipment. Also the output link is optimized for 50 ohms, you increase or decrease the loading to the output device by adjusting the coupling to the plate coil. If you can NOT get proper loading then either the load is not 50 ohms or the tube is question- able or dare I say it, you are doing it wrong. As with all things radio, YMMV, enjoy the rig, I love mine! I would appreciate the benefit of your actual experience or knowledge to assist me in interfacing this BC 610 E to a feedline. Thanks and 73, John, K5PGW Jim WB2FCN Real Radios weigh 400+ pounds, have handles, and that makes them PORTABLE http://eshop1.chem.buffalo.edu __ Our Main Website: http://www.amfone.net AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
Re: [AMRadio] T-368 FS on QTH
Joe Crawford wrote: W5DPP has his T-368 for sale on QTH.com. Ad #641748. Usual disclaimers apply. Which one, I wonder? He's got -at least- 2, but I -think- 3 of 'em. -- 73 __ Our Main Website: http://www.amfone.net AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
Re: [AMRadio] Mit Romoney disses Ham Radio
Peter Markavage wrote: Read the date; old news; topic beat to death several years ago; heard he loves ham now. My apologies, ya'll. Apparently, someone wanted people to think this had something to do with the current election mess. Guilty as charged. -- 73 __ Our Main Website: http://www.amfone.net AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
Re: [AMRadio] Loading antenna with BC 610 E
Ola Gang, The setup here is as follows: BC-610(*) output SO-239 to PL-259 coax run, to PL-259 to TX connector on E.F. Johnson TR-Switch. Antenna connector PL-259 to N connector. N Connector goes to the input of the ME-165 SWR/Wattmeter. N COnnector to output side of ME-165, coax run goes to input of E.F. Johnson 1 KW Matchbox through the directional coupler. The feed-line is homebrew open wire feeders to center fed dipole cut for the Low end of 80 meters, same antenna tunes 80-40-20 meters for the BC-610(*) transmitters. Works great, YMMV Jim WB2FCN - Original Message - From: Warren Elly [EMAIL PROTECTED] To: Discussion of AM Radio in the Amateur Service amradio@mailman.qth.net Sent: Thursday, January 17, 2008 8:13 PM Subject: Re: [AMRadio] Loading antenna with BC 610 E What my BC-610I has is an so239 mounted in the sidepanel just below the feed thrus. its connected to the feedthrus... i have a dowkey antenna relay hung off of it, and feed 375 watts out all day long into 50 ohms. I also pretune into a dummy load the same way. I use a tuner rated at 3k watts to tune 470 ohm feeders on a full wave loop on 75. using a 5kv 4 to 1 ballun to bring the coax into the shack. 73 warren w1gud __ Our Main Website: http://www.amfone.net AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
Re: [AMRadio] Home-brewing construction considerations
Is there a difference in feeding each of the inside sockets on the jack-bar with B+ from the top of the RF plate choke, vs having the two coils tied together, in the middle, and feeding B+ there? I understand that the potential is the same, but for the sake of having less stray capacitance and a 'cleaner' RF environment, which would be better, and please... tell me why? -Geoff/W5OMR I don't think it makes much difference, particularly on 160-40m and I have seen it done both ways. Actually, tying the two halves of the coil together in the middle would introduce less stray capacitance and inductance to the coil. I think the reason for the split coil and separate connectors for each half is to give you the option of metering each tube separately with the series fed circuit in which the coil is hot with HV and carries the DC plate current to the final. Also, those coils can be used in a link coupled antenna tuner, and the split coil gives the option of series feed using a conventional split stator capacitor. As for the vacuum capacitor, the tank should still remain balanced if care is taken with the layout. I suspect it would be more sensitive to unbalance due to stray capacitance and differences in lead length, than with all the capacitance in a split capacitor. Don k4kyv __ Our Main Website: http://www.amfone.net AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
[AMRadio] NO POLITICS
No discussions of politics are allowed on this email list people That rule has been in place since the very beginning. Thanks. __ Our Main Website: http://www.amfone.net AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
RE: [AMRadio] Mit Romoney disses Ham Radio
The article was posted on Wednesday 16 November 2005. Over two years go. It is irrelevant today. Ed, VA3ES __ Our Main Website: http://www.amfone.net AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
Re: [AMRadio] Home-brewing construction considerations
D. Chester wrote: I don't think it makes much difference, particularly on 160-40m and I have seen it done both ways. Having these two 250TH rf decks, side-by-side, allows me to see how things are done, both ways. The RF deck in what has been affectionately dubbed the 'Titanic' by K5SWK (I was a Johnny novice, experimenting and playing, and it was down more than it was up) has a metal bar that screws into the inside HDVL sockets, and the top of the RF choke screws into the center of that bar. B+ from the RF choke is applied to each of the two coils evenly. The new (to me) 250TH RF deck, built by Mike Spaan/W5IMF has a home-brewed HDVL spaced jack-bar, but the coil has only three banana plugs on the bottom side, and the inside of the two coils are tied together. Actually, tying the two halves of the coil together in the middle would introduce less stray capacitance and inductance to the coil. I think the reason for the split coil and separate connectors for each half is to give you the option of metering each tube separately with the series fed circuit in which the coil is hot with HV and carries the DC plate current to the final. It would seem, at first glance, that dual plate meters would certainly help in neutralizing the final. As for the vacuum capacitor, the tank should still remain balanced if care is taken with the layout. I suspect it would be more sensitive to unbalance due to stray capacitance and differences in lead length, than with all the capacitance in a split capacitor. The plug-in coil for this rig, with 3-pins on the bottom side of the jack-bar, also has a 50uuf vacuum capacitor across the entire coil, presumably for resonating on 75m. Each side is identical in construction. I'll take pictures, and put 'em somewhere. It's sometimes difficult to grasp the correct/proper words for description purposes. As an aside, I wired the thing up, and had it producing RF this evening. Even plate modulated the final, and made a good contact with Steve/WA1QIX there in Massachusetts. HE said the thing sounded fine, and audio was good, clean and clear. What concerned me was that the grid meter was dropping on voice peaks. Now, to be fair I was driving that final with a rice-box (TS-450S) at around 30w. It drove the grids to around 125mA. I never had a problem with the Viking II driving the other rig, using the same modulator. I also didn't hear the modulation transformer talk-back when I'm on the original rig, like I heard this evening. Was only running 200w. I'll do some more checking, tomorrow. Good night Mr and Mrs Ship and all the Americans at sea. from radio station KA5THB... no wait.. wrong call ;-) -- 73 de W5OMR __ Our Main Website: http://www.amfone.net AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
Re: [AMRadio] Mit Romoney disses Ham Radio
I found that out AFTER I wrote a nasty but respectful note to his campaign! The moderator is right on. No politics here! Enough! 73, John, W4AWM ** Start the year off right. Easy ways to stay in shape. http://body.aol.com/fitness/winter-exercise?NCID=aolcmp0030002489 __ Our Main Website: http://www.amfone.net AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
