- 1. Topband: Transformer Question (score: 1)
- Author: ford@cmgate.com (Ford Peterson)
- Date: Fri, 4 Jan 2002 16:33:17 -0600
- I need to know if there is a correct solution to transforming complex impedances. Assume a perfect 4:1 transformer at 1.83MHz. A load with R+/-j of 260 +330j I am fairly certain that the R term just
- /archives//html/Topband/2002-01/msg00015.html (7,221 bytes)
- 2. Topband: Transformer Question (score: 1)
- Author: K9AY" <k9ay@k9ay.com (K9AY)
- Date: Fri, 4 Jan 2002 22:01:44 -0500
- Ford You started out OK... You can cancel the reactance at either side of the transformer. The 260 +j330 will be transformed to about 65 +j82.5, but not exactly, due to stray inductance, and the capa
- /archives//html/Topband/2002-01/msg00018.html (8,623 bytes)
- 3. Topband: Transformer Question (score: 1)
- Author: ac7a@gci-net.com (Thomas)
- Date: Fri, 04 Jan 2002 23:44:06 -0700
- Hello Ford, Unfortunately, it is not quite that simple. The circuit has to be analyzed such that it includes the transformer's primary, secondary, and mutual impedances, such that: Zin = Z11 + ((w^2)
- /archives//html/Topband/2002-01/msg00020.html (9,428 bytes)
- 4. Topband: Transformer Question (score: 1)
- Author: dbowker@blackfly.sjv.net (Dave Bowker)
- Date: Sat, 5 Jan 2002 08:36:52 -0500
- It's not that simple. The $:1 transformer (or any transformer) can only transform a pure resistance (Z = R + j0) in a direct division ratio, i.e., if you have a pure 200 + j0 resistance across the hi
- /archives//html/Topband/2002-01/msg00021.html (9,966 bytes)
- 5. Topband: Transformer Question (score: 1)
- Author: k9ay@k9ay.com (K9AY)
- Date: Sat, 05 Jan 2002 16:55:30 +0000
- Ford, Thomas I quickly built and measured the situation you described. The transfomer is conventional (separate primary and secondary windings), but tightly inter-wound for k~1, with the right ferrit
- /archives//html/Topband/2002-01/msg00024.html (7,814 bytes)
- 6. Topband: TRANSFORMER QUESTION (score: 1)
- Author: "Mr. and Mrs. Magoo" <magoo@isp.ca>
- Date: Thu, 8 Dec 2005 16:10:27 -0500
- I recently built and installed a 2:1 matching transformer on a pair of phased 750 ft Beverages. The antenna works extremely well on 160 and 80, but I noticed that it is not flat much above 5 mhz, unl
- /archives//html/Topband/2005-12/msg00082.html (6,682 bytes)
- 7. Re: Topband: TRANSFORMER QUESTION (score: 1)
- Author: topband-bounces@contesting.com (by way of Bill Tippett<btippett@alum.mit.edu>)
- Date: Thu, 08 Dec 2005 17:48:08 -0500
- Bill, If you are using the autoformer (single winding with a tap) design from Tom's web site, I'm not surprised to hear about the limited high frequency response. Autoformers are not particularly bro
- /archives//html/Topband/2005-12/msg00086.html (7,307 bytes)
- 8. Re: Topband: TRANSFORMER QUESTION (score: 1)
- Author: "Tom Rauch" <w8ji@contesting.com>
- Date: Thu, 8 Dec 2005 18:48:13 -0500
- tap) design limited high broadband (see And they toroid than a I'm not sure exactly was Sevik is talking about, but if he said that nothing is further from the truth. It makes no sense in theory eit
- /archives//html/Topband/2005-12/msg00088.html (8,955 bytes)
- 9. Re: Topband: TRANSFORMER QUESTION (score: 1)
- Author: "Tom Rauch" <w8ji@contesting.com>
- Date: Thu, 8 Dec 2005 18:54:03 -0500
- Typically the 2:1 auto transformers I wind on those cores have a 1.5:1 VSWR BW up to 30-40 MHz. They are about 1.25 : 1 SWR or less at 15 MHz, and nearly 1.1:1 at 300 kHz. Did you terminate the tran
- /archives//html/Topband/2005-12/msg00089.html (7,902 bytes)
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