Re: [AMRadio] Negative Bias Supply on Viking II
That sounds right Nick. That would be the normal arrangement for any negative bias power supply. Same style circuit as used in many many transmitter designs from the tube era. 73s - Bry, AF4K... From: Nick England navy.ra...@gmail.com 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. -~ø¤º°º¤ø~-ßrÿ in FLÕRÎÐÁ-~ø¤º°º¤ø~- __ 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
