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#1
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Wanted, Diodes
I am looking for a few (10) diodes 1N270...It is a germanium and used
in Double Balanced mixers in SSB generation..Most suppliers have a $25 to $50 min order and I don`t care for that.. thanks Harold W4PQW |
#2
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Wanted, Diodes
"mrhaney" wrote in message ... I am looking for a few (10) diodes 1N270...It is a germanium and used in Double Balanced mixers in SSB generation..Most suppliers have a $25 to $50 min order and I don`t care for that.. thanks Harold W4PQW Hi Harold. I can supply your needs, but for info, I have never. in a lot of years, called on MiniCircuits Labs (MO) for a small order and not have them waive the minimum order charge if needed. VERY nice folks to work with and they make better balanced mixers than you will. They have some black magic in their ferrite department. W4ZCB |
#3
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Wanted, Diodes
"mrhaney" wrote in message ... I am looking for a few (10) diodes 1N270...It is a germanium and used in Double Balanced mixers in SSB generation..Most suppliers have a $25 to $50 min order and I don`t care for that.. thanks Harold W4PQW Have you tried Dans Small Parts? Are hot carrier diodes an acceptable substitute for that application? 73 Pete |
#4
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Wanted, Diodes
On Aug 17, 9:12*pm, mrhaney wrote:
I am looking for a few (10) diodes 1N270...It is a germanium and used in Double Balanced mixers in SSB generation..Most suppliers have a $25 to $50 min order and I don`t care for that.. thanks * Harold W4PQW Are you trying to reproduce something from a 60's handbook? I remember them speccing 1N270's but that's because those were the parts people had in the junkboxes back then. There is nothing at all magic about germanium here. The silicon diodes will require slightly more drive voltage to switch but that's not a big deal as you always drive them way into saturation anyway. NTE109 is the ECT/NTE number for a their medium-voltage germanium replacement, officially listed in the NTE sub book, and Mouser and maybe even your local radio/TV repairman would have some. Mouser has no minimum order. You will have much better luck using 1N914's or 1N4148's or even better a real matched DBM from Minicircuits et al. "Experimental Methods in RF Design" has a lot of good scoop on mixers that goes way beyond anything in a 60's ARRL handbook. Tim N3QE |
#5
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Wanted, Diodes
On Aug 17, 9:12 pm, mrhaney wrote:
I am looking for a few (10) diodes 1N270...It is a germanium and used in Double Balanced mixers in SSB generation..Most suppliers have a $25 to $50 min order and I don`t care for that.. thanks Harold W4PQW Hey Harold: Try your luck with this guy: http://www.angelfire.com/electronic2/index1/index.html takes paypal has tonnes of them in stock and only charges $3.95 for shipping and handling for an order like yours The shipping cost more than the parts but there's no minimum order. 73 OM N8ZU |
#6
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Wanted, Diodes
On Aug 17, 6:12*pm, mrhaney wrote:
I am looking for a few (10) diodes 1N270...It is a germanium and used in Double Balanced mixers in SSB generation..Most suppliers have a $25 to $50 min order and I don`t care for that.. thanks * Harold W4PQW So after all that, any hints on what the original project was? Even in the 1970s people were speccing matched silicon diodes (e.g. 1N914) or hot carrier diodes (e.g. 5082-2800) for mixers. Laura Halliday VE7LDH "Non sequitur. Your ACKS are Grid: CN89mg uncoordinated." ICBM: 49 16.05 N 122 56.92 W - Nomad the Network Engineer |
#7
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Wanted, Diodes
On Aug 23, 3:39*pm, laura halliday wrote:
On Aug 17, 6:12*pm, mrhaney wrote: I am looking for a few (10) diodes 1N270...It is a germanium and used in Double Balanced mixers in SSB generation..Most suppliers have a $25 to $50 min order and I don`t care for that.. thanks * Harold W4PQW So after all that, any hints on what the original project was? Even in the 1970s people were speccing matched silicon diodes (e.g. 1N914) or hot carrier diodes (e.g. 5082-2800) for mixers. At least two volumes of "Single Side Band for the Radio Amateur" and many ARRL handbooks from the 60's show 1N270's used in balanced mixers. It was a jellybean of the time, it's odd that someone would not realize it and slavishly want to use it rather than something more readily available (and performance-wise far superior) today. Probably the same guys who insist on carbon-composition resistors everywhere today too :-). There are some things that appear in old construction articles that are worth finding. For example, the BC-453/454/455's tuning capacitors and drive mechanism are truly superb and I still keep my eyes open for them today :-). Tim. |
#8
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Wanted, Diodes
I have 1N34A's... will they do?
Cheers, __ Gregg |
#9
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Wanted, Diodes
On Aug 25, 6:14 am, Tim Shoppa wrote:
On Aug 23, 3:39 pm, laura halliday wrote: On Aug 17, 6:12 pm, mrhaney wrote: I am looking for a few (10) diodes 1N270...It is a germanium and used in Double Balanced mixers in SSB generation..Most suppliers have a $25 to $50 min order and I don`t care for that.. thanks Harold W4PQW So after all that, any hints on what the original project was? Even in the 1970s people were speccing matched silicon diodes (e.g. 1N914) or hot carrier diodes (e.g. 5082-2800) for mixers. At least two volumes of "Single Side Band for the Radio Amateur" and many ARRL handbooks from the 60's show 1N270's used in balanced mixers. It was a jellybean of the time, it's odd that someone would not realize it and slavishly want to use it rather than something more readily available (and performance-wise far superior) today. Probably the same guys who insist on carbon-composition resistors everywhere today too :-). There are some things that appear in old construction articles that are worth finding. For example, the BC-453/454/455's tuning capacitors and drive mechanism are truly superb and I still keep my eyes open for them today :-). Tim. Indeed. I have several old ARRL and RSGB Handbooks and a number of older references (including Single Sideband for the Radio Amateur). You can see the fashions change. At one time the cool part to use was the 7360 beam deflection mixer tube; at other times the challenge was to see how many 40673 MOSFETs you could use in a single radio. Many of these designs are difficult to reproduce now. I'll see your BC-455 tuning capacitor and raise you an Eddystone dial. :-) You can make nice radios by applying the right technology to the problem. My recipe for a stable VFO nowadays is a postage-stamp size surface mount board mummified in bubble wrap and stuck to the end of a good, solid air variable capacitor. Laura Halliday VE7LDH "Non sequitur. Your ACKS are Grid: CN89mg uncoordinated." ICBM: 49 16.05 N 122 56.92 W - Nomad the Network Engineer |
#10
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Wanted, Diodes
On Aug 26, 11:30*am, laura halliday wrote:
Indeed. I have several old ARRL and RSGB Handbooks and a number of older references (including Single Sideband for the Radio Amateur). You can see the fashions change. At one time the cool part to use was the 7360 beam deflection mixer tube; at other times the challenge was to see how many 40673 MOSFETs you could use in a single radio. Many of these designs are difficult to reproduce now. What's amazing is that some of the SSB rigs appearing in the 60's in the pages of QST use not one, not two, but three 7360's :-). 40673's were also used with wild abandon. If someone wants an honest- to-goodness 40673 they can pay $15 for a NTE221 in a metal can, but most experimenters would use a BF998, obviously a different package but same function. I'll see your BC-455 tuning capacitor and raise you an Eddystone dial. :-) You can make nice radios by applying the right technology to the problem. My recipe for a stable VFO nowadays is a postage-stamp size surface mount board mummified in bubble wrap and stuck to the end of a good, solid air variable capacitor. The brass-screw-in-a-solenoid is something I just tried in my reproduction of the MMR-40 and I am very impressed with its stability and mechanical simplicity as a PTO. A similar but not identical mechanical design is used in the WA6OTP PTO, I haven't tried it yet. Tim. |
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