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#1
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SE?
Hello
I am looking at http://cgi.ebay.com/ws/eBayISAPI.dll...1151 681&rd=1 can I use the transformer as SE and what tube. My gess are 45 or 2A3 Regards Benny |
#2
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"Benny Højvælde" wrote:
Hello I am looking at http://cgi.ebay.com/ws/eBayISAPI.dll...1151 681&rd=1 can I use the transformer as SE and what tube. My gess are 45 or 2A3 Regards Benny The Hammond 365 has only a 3/4" x 3/4" core & no gap. Not suitable for SE. Price in the 1960 Hammond Catalogue is $3.95 Canadian. Interesting to collectors only. JLS |
#3
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John Stewart wrote: "Benny Højvælde" wrote: Hello I am looking at http://cgi.ebay com/ws/eBayISAPI.dll?ViewItem&category=67815&item=5771151 681&rd=1 can I use the transformer as SE and what tube. My gess are 45 or 2A3 Regards Benny The Hammond 365 has only a 3/4" x 3/4" core & no gap. Not suitable for SE. Price in the 1960 Hammond Catalogue is $3.95 Canadian. Interesting to collectors only. Ah, the resident Hammond expert has spoken. But he could use them in a parafeed amp with a choke for the DC to the anode of a 2A3 and then have the OPTs cap coupled from anode to one end of the primary with the other end grounded. They would surely handle 3 watts? Patrick Turner. JLS |
#4
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Patrick Turner wrote:
John Stewart wrote: "Benny H=F8jv=E6lde" wrote: Hello I am looking at http://cgi.ebay com/ws/eBayISAPI.dll?ViewItem&category=3D67815&item=3D577 1151681&rd=3D= 1 can I use the transformer as SE and what tube. My gess are 45 or 2A3 Regards Benny The Hammond 365 has only a 3/4" x 3/4" core & no gap. Not suitable fo= r SE. Price in the 1960 Hammond Catalogue is $3.95 Canadian. Interesting to collectors only. Ah, the resident Hammond expert has spoken. But he could use them in a parafeed amp with a choke for the DC to the anode of a 2A3 and then have the OPTs cap coupled from anode to one end of the primary with the other end grounded. They would surely handle 3 watts? Patrick Turner. JLS That would work, marginally. In those daze Hammond claimed only 80 to 700= 0 Hz for that transformer class. It might be OK for telephone work!! Well, perhaps a little better than that!! I used a Hammond 465 (next thing up) in a PP 6L6G amp. The driver was a 6SN7GT hooked up as a 'plain jane' triode voltage amp & split load phase splitter. It had a whole 5 db NFB. DF was a nice round one. Ahead of that= there was a 6SC7 mixer & a 6SJ7 mic amp on board as well. Used as a PA am= p, so OK in that application. The date on my early pencil drawing sez Octobe= r, 1955. The Hammond 400 Series transformers had a 1" x 1" core. So perhaps a litt= le better. But I guess core materials have got a lot better in the last 50 years. Have Fun Anyway, John Stewart |
#5
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John Stewart wrote: Patrick Turner wrote: John Stewart wrote: "Benny Højvælde" wrote: Hello I am looking at http://cgi.ebay com/ws/eBayISAPI.dll?ViewItem&category=67815&item=5771151 681&rd=1 can I use the transformer as SE and what tube. My gess are 45 or 2A3 Regards Benny The Hammond 365 has only a 3/4" x 3/4" core & no gap. Not suitable for SE. Price in the 1960 Hammond Catalogue is $3.95 Canadian. Interesting to collectors only. Ah, the resident Hammond expert has spoken. But he could use them in a parafeed amp with a choke for the DC to the anode of a 2A3 and then have the OPTs cap coupled from anode to one end of the primary with the other end grounded. They would surely handle 3 watts? Patrick Turner. JLS That would work, marginally. In those daze Hammond claimed only 80 to 7000 Hz for that transformer class. It might be OK for telephone work!! Well, perhaps a little better than that!! I used a Hammond 465 (next thing up) in a PP 6L6G amp. The driver was a 6SN7GT hooked up as a 'plain jane' triode voltage amp & split load phase splitter. It had a whole 5 db NFB. DF was a nice round one. Ahead of that there was a 6SC7 mixer & a 6SJ7 mic amp on board as well. Used as a PA amp, so OK in that application. The date on my early pencil drawing sez October, 1955. The Hammond 400 Series transformers had a 1" x 1" core. So perhaps a little better. But I guess core materials have got a lot better in the last 50 years. GOSS for E&I assembled cores had µ = about 5,000 max in 1953 when RDH4 was written. It was quite good stuff and good enough for general use today with OPTs and mains tranies. But I now get E&I GOSS cores with assembled µ max = 17,000, so there is more than 3 times the inductance for most winding apps. But I still have to use the same amount of iron for a given OPT because the Fsat for a given winding with plain Lycore 150, µ = 2,700, is very near the same for the GOSS. But the GOSS core will have 20DB+ less iron caused distortion at LF, until it saturates, and then its like all iron, it saturates. But its very easy to make an OPT with GOSS lams which will contribute far less distortion to the signal than the tubes will. Patrick Turner. Have Fun Anyway, John Stewart |
#6
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"Benny Højvælde" wrote: Hello I am looking at http://cgi.ebay.com/ws/eBayISAPI.dll...1151 681&rd=1 can I use the transformer as SE and what tube. My gess are 45 or 2A3 If it is not stated as being an SE transformer, it most likely isn't. Since there is a CT mentioned, it is probably PP. If it is PP, then it won't have an air gap. Probably it is quite unsuitable for SET, unless used in a para-feed circuit where it might be used ok without a gap. And having been made in the late 1940s, these may not be all that wonderful since hardly anyone had the concerns about bandwidth that a few discerning people have today. Have you phoned Hammond to ask them about these old models? Sorry to be negative but most old OPTs I find are crap. Patrick Turner Regards Benny |
#7
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Most of the new ones are too... but even good ones can't make a good
amplifier out of single ended. For fullrange use SE is simply poor. And no one will build limited bandpass SE transformers because no one smart enough to use them well will fuool with SE. |