[AMRadio] Negative Bias Supply on Viking II
I've begun recapping the Viking II I'm working on. The dual 15Uf/150V cap connected to the 6AL5 has the positive sides of the cap going to the 6AL5 and choke and the negative side going to ground. Since this guy is intended to produce negative voltage and the connection is to the plates of the 6AL5 rather than the cathodes, shouldn't the filter caps (I'm using two 22Uf/450V) positive side be going to ground and the negative sides going to the 6AL5 plates? I'm reasonably certain this is correct, but the original design used a dual (two caps in one package with a common ground lead) cap and I've never seen one where the common lead wasn't the negative sides of the electrolytic cap. Thanks for your advice. arnie - W1GCI __ Our Main Website: http://www.amfone.net AMRadio mailing list Searchable Archives: http://www.mail-archive.com/amradio@mailman.qth.net/ List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Post: AMRadio@mailman.qth.net To unsubscribe, send an email to amradio-requ...@mailman.qth.net with the word unsubscribe in the message body. This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [AMRadio] Negative Bias Supply on Viking II
Hi Arnie: be careful with the answers you get, if this is a simple full wave I would expect the plates to be tied together and only one cap. I am not familer with Vikings, but hopefully you get an answer from someone that knows of what they speak. I have seen some strange circuits that made no sense till I carefully sketched them out, then its sort of OH so that what it is Bernie- Original Message - From: Arnie Adelman arnie.adel...@infosec-consultant.com To: amradio@mailman.qth.net Sent: Saturday, March 27, 2010 7:29 AM Subject: [AMRadio] Negative Bias Supply on Viking II I've begun recapping the Viking II I'm working on. The dual 15Uf/150V cap connected to the 6AL5 has the positive sides of the cap going to the 6AL5 and choke and the negative side going to ground. Since this guy is intended to produce negative voltage and the connection is to the plates of the 6AL5 rather than the cathodes, shouldn't the filter caps (I'm using two 22Uf/450V) positive side be going to ground and the negative sides going to the 6AL5 plates? I'm reasonably certain this is correct, but the original design used a dual (two caps in one package with a common ground lead) cap and I've never seen one where the common lead wasn't the negative sides of the electrolytic cap. Thanks for your advice. arnie - W1GCI __ Our Main Website: http://www.amfone.net AMRadio mailing list Searchable Archives: http://www.mail-archive.com/amradio@mailman.qth.net/ List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Post: AMRadio@mailman.qth.net To unsubscribe, send an email to amradio-requ...@mailman.qth.net with the word unsubscribe in the message body. This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Our Main Website: http://www.amfone.net AMRadio mailing list Searchable Archives: http://www.mail-archive.com/amradio@mailman.qth.net/ List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Post: AMRadio@mailman.qth.net To unsubscribe, send an email to amradio-requ...@mailman.qth.net with the word unsubscribe in the message body. This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [AMRadio] Negative Bias Supply on Viking II
I don't have a Viking II any more, but the schematic certainly shows the two negative leads of C12-C13 (dual 15uf/150v) going to either side of the bias supply choke and the positive lead to ground. In the photo in the manual it looks like this dual cap indeed has two black (negative) leads and a single red (common positive) lead. Nearby is a dual 15uf/450v (C10-C11) in the B+ line, with a single negative lead to ground and maybe that's confused someone? Manual at http://bama.edebris.com/manuals/johnson/viking2(2)/ cheers, Nick K4NYW On Sat, Mar 27, 2010 at 7:29 AM, Arnie Adelman arnie.adel...@infosec-consultant.com wrote: I've begun recapping the Viking II I'm working on. The dual 15Uf/150V cap connected to the 6AL5 has the positive sides of the cap going to the 6AL5 and choke and the negative side going to ground. Since this guy is intended to produce negative voltage and the connection is to the plates of the 6AL5 rather than the cathodes, shouldn't the filter caps (I'm using two 22Uf/450V) positive side be going to ground and the negative sides going to the 6AL5 plates? I'm reasonably certain this is correct, but the original design used a dual (two caps in one package with a common ground lead) cap and I've never seen one where the common lead wasn't the negative sides of the electrolytic cap. Thanks for your advice. arnie - W1GCI __ Our Main Website: http://www.amfone.net AMRadio mailing list Searchable Archives: http://www.mail-archive.com/amradio@mailman.qth.net/ List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Post: AMRadio@mailman.qth.net To unsubscribe, send an email to amradio-requ...@mailman.qth.net with the word unsubscribe in the message body. This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
[AMRadio] sdr-iq
well I am going to stir the pot again with my probable final comments on my SDR-IQ. first the good, never had a panadapter or bandscope, it works great for that. The filters are very good. The issues to me are the following, it is noisy, to itself and also to a receiver on the same antenna, it lacks sensitivity, it has spurs, and the big one to me is the audio quality, a moderate strength AM signal is difficult to understand and when on my hollow state stuff it is nearly %100 copy. The present computer is a 2.2gig quad core, no performance change above a single core 1.8 gig. Numerous different audio systems confirm that it is the nature of the beast. I have read numerous articles on D-A and A-D processing and believe that 14 bit is not going to do the job that I want. I suspect 24 bit and a much higher sampling rate, 150 meg? would just about cure the audio issue for me. I am starting to believe that the glowing reports written about SDR are prepared by those that have never used an old VT receiver or have one available to run beside the sdr. My FT1000 Mark V had glowing reports and I am really disappointed with it. I have an ever deepening respect for those that designed and built the old classic receivers. Looking at noise figures and sensitivity on those old dogs places them very close to theoretical limits, pretty amazing. I have put my money where my mouth, I should, about April 10 or so have a completely reman R-390A. I was going to try the Flex 5000, but as I posted earlier they did not see fit to respond to my questions, perhaps thinking the questions were not fit to respond too. Earth hour is today, be sure to turn on all of your lights to help save the grid and generators. ! Bernie W8RPW __ Our Main Website: http://www.amfone.net AMRadio mailing list Searchable Archives: http://www.mail-archive.com/amradio@mailman.qth.net/ List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Post: AMRadio@mailman.qth.net To unsubscribe, send an email to amradio-requ...@mailman.qth.net with the word unsubscribe in the message body. This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [AMRadio] sdr-iq
Did you try adjusting the rf and IF gain settings? The IF gain adds a lot of noise using spectravue... Also, what programs did you use with the sdr-iq? Winrad seems to have much better audio with less noise. I don't often use the sdr-iq as a receiver, sometimes I use it to listen in the den, as its very small and I am using the laptop anyway. The flex 5000 seems to be a very good receiver. Maybe its not quite the same as an old tube receiver, but has other advantages: It can handle 150% modulation with its sync detector, It can do diversity, and noise null, The filters are fantastic, and you can set them as wide or as narrow as you want, and slide them around to get rid of qrm, The frequency response can be whatever you want, down below 20 Hz. You get a great band scope. You can record audio right off the air without altering it (and play it back over the air as well). Its all mode. For weak AM signals, the homebrew seems to be just a slight bit better, but the homebrew receivers are much better than anything else I ever owned, better then the R390a. I usually use both, the homebrew for audio and scope output, the 5000 as a band scope, and sometimes for the filters when things get tight. On the flex, you can slide the passband 25 Hz off a carrier and its gone. Brett N2DTS - Original Message - From: Bernie Doran qedconsulta...@embarqmail.com To: Discussion of AM Radio in the Amateur Service amradio@mailman.qth.net Sent: Saturday, March 27, 2010 1:13 PM Subject: [AMRadio] sdr-iq well I am going to stir the pot again with my probable final comments on my SDR-IQ. first the good, never had a panadapter or bandscope, it works great for that. The filters are very good. The issues to me are the following, it is noisy, to itself and also to a receiver on the same antenna, it lacks sensitivity, it has spurs, and the big one to me is the audio quality, a moderate strength AM signal is difficult to understand and when on my hollow state stuff it is nearly %100 copy. The present computer is a 2.2gig quad core, no performance change above a single core 1.8 gig. Numerous different audio systems confirm that it is the nature of the beast. I have read numerous articles on D-A and A-D processing and believe that 14 bit is not going to do the job that I want. I suspect 24 bit and a much higher sampling rate, 150 meg? would just about cure the audio issue for me. I am starting to believe that the glowing reports written about SDR are prepared by those that have never used an old VT receiver or have one available to run beside the sdr. My FT1000 Mark V had glowing reports and I am really disappointed with it. I have an ever deepening respect for those that designed and built the old classic receivers. Looking at noise figures and sensitivity on those old dogs places them very close to theoretical limits, pretty amazing. I have put my money where my mouth, I should, about April 10 or so have a completely reman R-390A. I was going to try the Flex 5000, but as I posted earlier they did not see fit to respond to my questions, perhaps thinking the questions were not fit to respond too. Earth hour is today, be sure to turn on all of your lights to help save the grid and generators. ! Bernie W8RPW __ Our Main Website: http://www.amfone.net AMRadio mailing list Searchable Archives: http://www.mail-archive.com/amradio@mailman.qth.net/ List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Post: AMRadio@mailman.qth.net To unsubscribe, send an email to amradio-requ...@mailman.qth.net with the word unsubscribe in the message body. This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Our Main Website: http://www.amfone.net AMRadio mailing list Searchable Archives: http://www.mail-archive.com/amradio@mailman.qth.net/ List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Post: AMRadio@mailman.qth.net To unsubscribe, send an email to amradio-requ...@mailman.qth.net with the word unsubscribe in the message body. This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [AMRadio] More Hash and Buzzies
Ed: I wonder if you might be so kind as to e-mail your research on RFI in your HVAC system. Please send to coastal...@coastalnow.net (no file size limit). It too have done a lot of searching in my home for sources of noise. First by running my radio from a battery and tripping the main circuit breaker to see what noise goes away. Then, going down the line of each individual breaker until I located the source -- assuming it is inside the house. I work for an electric utility company and have been able to help resolve a number of complaints of powerline interference -- mostly in my own neighborhood. Generally, those powerline problems have been caused by blown lightning arrestors where the expulsion cartridge has not completely blown the stinger off the bottom of the arrestor. I found three in my neighborhood like that. We were glad to get them replaced but may not have know about them unless someone (like a ham operator) had complained of noise. For years our line crews could only have AM radios installed in their service trucks because that helped them to become more aware of powerline noise as they drove throughout the system. Now, of course, you can't buy a truck with just an AM radio. J. Mark Bolton KA4CID Richmond Hill, GA Visit my blog at www.KA4CID.blogspot.com -Original Message- From: amradio-boun...@mailman.qth.net [mailto:amradio-boun...@mailman.qth.net] On Behalf Of Ed Sieb Sent: Friday, March 26, 2010 7:19 PM To: w...@brightok.net Cc: Discussion of AM Radio in the Amateur Service Subject: Re: [AMRadio] More Hash and Buzzies Jim, I have all the dope on mitigating RFI out of HVAC, gas furnaces, etc, etc. I have a Trane XV95 gas furnace which spews trash out on HF. I successfully mitigated that noise. Let me know if you can handle 8Mb of down loads and I will send you my entire package. Ed, VA3ES - Jim/W5JO wrote: I encountered the same situation with the FCC over the air handler unit to my HVAC, it is a multi speed motor that is controlled by a PWM signal.The noise it puts out is nothing like this thing though but I followed up with the manufacturer and they would not, (first) admit the problem with in their unit, and (second) would not provide any help other than telling me to buy a filter from Radio Shack. __ Our Main Website: http://www.amfone.net AMRadio mailing list Searchable Archives: http://www.mail-archive.com/amradio@mailman.qth.net/ List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Post: AMRadio@mailman.qth.net To unsubscribe, send an email to amradio-requ...@mailman.qth.net with the word unsubscribe in the message body. This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Our Main Website: http://www.amfone.net AMRadio mailing list Searchable Archives: http://www.mail-archive.com/amradio@mailman.qth.net/ List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Post: AMRadio@mailman.qth.net To unsubscribe, send an email to amradio-requ...@mailman.qth.net with the word unsubscribe in the message body. This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [AMRadio] sdr-iq
Don't know enough about the 5000's receiver, but a couple years ago, I talked with W5GI on 3.880 as he was shaking out the prototype. None the old buzzards, nor I, could tell it from a plate-modulated rig. I've heard several on the air since, and they seem to have pretty decent transmit audio, guess all the modern digital processing in the computer helps out there? Who am I to talk? I run a single 5763, modulated by a pair of 6AQ5's into an SB221 for 100W., and listen on an HQ-140A,or FT-847 ricebox when the QRN,QRM,etc. gets nasty. Wish I had a realRX, R-399, 75-A. etc. Maybe someday.HI I'm burning all the lights, idling both trucks, and dumping 1500W. into the 15M. ant., trying to work B1Z on 15M in the WPX contest. Happy Earth Hour Jon AD5HR --- On Sat, 3/27/10, Brett Gazdzinski brett.gazdzin...@verizon.net wrote: From: Brett Gazdzinski brett.gazdzin...@verizon.net Subject: Re: [AMRadio] sdr-iq To: Discussion of AM Radio in the Amateur Service amradio@mailman.qth.net Date: Saturday, March 27, 2010, 8:16 PM Did you try adjusting the rf and IF gain settings? The IF gain adds a lot of noise using spectravue... Also, what programs did you use with the sdr-iq? Winrad seems to have much better audio with less noise. I don't often use the sdr-iq as a receiver, sometimes I use it to listen in the den, as its very small and I am using the laptop anyway. The flex 5000 seems to be a very good receiver. Maybe its not quite the same as an old tube receiver, but has other advantages: It can handle 150% modulation with its sync detector, It can do diversity, and noise null, The filters are fantastic, and you can set them as wide or as narrow as you want, and slide them around to get rid of qrm, The frequency response can be whatever you want, down below 20 Hz. You get a great band scope. You can record audio right off the air without altering it (and play it back over the air as well). Its all mode. For weak AM signals, the homebrew seems to be just a slight bit better, but the homebrew receivers are much better than anything else I ever owned, better then the R390a. I usually use both, the homebrew for audio and scope output, the 5000 as a band scope, and sometimes for the filters when things get tight. On the flex, you can slide the passband 25 Hz off a carrier and its gone. Brett N2DTS - Original Message - From: Bernie Doran qedconsulta...@embarqmail.com To: Discussion of AM Radio in the Amateur Service amradio@mailman.qth.net Sent: Saturday, March 27, 2010 1:13 PM Subject: [AMRadio] sdr-iq well I am going to stir the pot again with my probable final comments on my SDR-IQ. first the good, never had a panadapter or bandscope, it works great for that. The filters are very good. The issues to me are the following, it is noisy, to itself and also to a receiver on the same antenna, it lacks sensitivity, it has spurs, and the big one to me is the audio quality, a moderate strength AM signal is difficult to understand and when on my hollow state stuff it is nearly %100 copy. The present computer is a 2.2gig quad core, no performance change above a single core 1.8 gig. Numerous different audio systems confirm that it is the nature of the beast. I have read numerous articles on D-A and A-D processing and believe that 14 bit is not going to do the job that I want. I suspect 24 bit and a much higher sampling rate, 150 meg? would just about cure the audio issue for me. I am starting to believe that the glowing reports written about SDR are prepared by those that have never used an old VT receiver or have one available to run beside the sdr. My FT1000 Mark V had glowing reports and I am really disappointed with it. I have an ever deepening respect for those that designed and built the old classic receivers. Looking at noise figures and sensitivity on those old dogs places them very close to theoretical limits, pretty amazing. I have put my money where my mouth, I should, about April 10 or so have a completely reman R-390A. I was going to try the Flex 5000, but as I posted earlier they did not see fit to respond to my questions, perhaps thinking the questions were not fit to respond too. Earth hour is today, be sure to turn on all of your lights to help save the grid and generators. ! Bernie W8RPW __ Our Main Website: http://www.amfone.net AMRadio mailing list Searchable Archives: http://www.mail-archive.com/amradio@mailman.qth.net/ List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Post: AMRadio@mailman.qth.net To unsubscribe, send an email to amradio-requ...@mailman.qth.net with the word unsubscribe in the message
Re: [AMRadio] sdr-iq
Hi Bernie, I have gone back and forth on the receive audio question with my rigs. I have never had a PC controlled receiver, but I have a Kenwood TS870 which is a 24 bit dsp firmware receiver. I have the 1000MP Mk V also and I agree that the stock audio is not very good. I widened the stock 6 KHz passband AM IF and tapped the AM detector and brought that signal out to an external tube push pull amp and speaker. Those two things made a vast difference on AM and it sounds like a tube boat anchor rx now. Next I get the 75A3 and fire it up and I'm not very thrilled with the audio quality. At this point the audio I get from the stock TS870 with a 14 KHz passband is almost as good as the modified Yaesu. 75A3 is worst of the three. But I tap the detector on the A3 and with a 10 KHz AM passband, put its audio out to another p.p. vintage AF amp and set of speakers. Now I prefer it over the TS870 and it is at least as good or better than the tapped and modified Yaesu. I have never had a SX28 or any of the audio ba receivers (many of which seem to be general coverage) but I have concluded that most ham receivers need some help of one sort or another as they were not intended for great audio but rather for chasing dx. 73 Rob K5UJ __ Our Main Website: http://www.amfone.net AMRadio mailing list Searchable Archives: http://www.mail-archive.com/amradio@mailman.qth.net/ List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Post: AMRadio@mailman.qth.net To unsubscribe, send an email to amradio-requ...@mailman.qth.net with the word unsubscribe in the message body. This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
