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Isn't Type 43 the recommended as a Balun "Core Material" ?
Type 43 is optimal for the shortwave (HF) spectrum. Why isn't Type 61 also a 'suggested' Balun Core Material ? The 'Q' of type-61 makes it too selective for HF. You want the balun to be broadband not peaked for a particular frequency. Is it possible that the frequency range is more dependent on the number of turns (inductance?) than the actual material? This is not a trick question... The ferrite composition plays a large role in determining the effective frequency range of the coil. In the case of a balun/unun you're not trying to make a tuned coil. You want it to be efficient over the desired frequency range. See the following webpage for ferrite core info': http://www.universal-radio.com/catal.../amidonT1.html FWIW: Reading your statement about the Binocular Cores, I have just ordered some from Universal-Radio.Com to Test. It is my understanding that One Turn 'counts' for Two when You use a Binocular Core. Now Is That True ? I would love to know this also, and also see a GOOD diagram of how to wire a binocular core. Here's how to wind ferrite cores, including binocular ones: http://www.oselectronics.com/downloa...ansformers.pdf ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 100,000 Newsgroups ---= East/West-Coast Server Farms - Total Privacy via Encryption =--- |
= = = (bpnjensen) wrote in message
= = = . com... (RHF) wrote in message m... Good information snipped STARMAN, Isn't Type 43 the recommended as a Balun "Core Material" ? Why isn't Type 61 also a 'suggested' Balun Core Material ? NOTE: Matching Transformer = Balun = UnUn True Story: A while back I bought a Grab Bag of Feritte Cores on eBay. Some of them had a #20 Enameled Wire wrapped on them with 36 Turns. They were about 1" OD x 1/2" ID x 1/2" H. So I thought, why not try them as an Matching Transformer on an 'old' Telephone Two Wire Service Line (pre-1950s) that runs overhead about 75 Ft from the Power Pole to the House. Being lazy I simply wrapped a Twelve Turn (12T) Secondary and wired it up with a #22 Magnet Wire from a RadioShack 'three pack' Catalog # 278-1345 ($5). Well 36:12 Turns worked good for AM/MW and up to 7 MHz but the Signal Levels fell off after 7 MHz. So then I tried Reducing the Primary to 30 Turns and the Secondary to 10 Turns. Again the AM/MW Band was good and the Shortwave coverage went up to 23 MHz. Not being one to settle for 'good enough'; I then tried Reducing the Primary to 24 Turns and the Secondary to 8 Turns. Well the AM/MW Reception went down and the Shortwave Bands reception picked up to the CB Band. So it seems that the 'majic' 30 Turns and 10 Turns worked the best for my needs using this ?Core?. RHF - it sounds like you did not know what the material for this core was (43 vs. 61 or other) - right? Is it possible that the frequency range is more dependent on the number of turns (inductance?) than the actual material? This is not a trick question... BJ, YES - I DID NOT KNOW - I think that sometimes you just get 'lucky' :o) READ: Assessing unknown Ferrite Toroids http://www.alan.melia.btinternet.co.uk/toroids.htm As for Me the whole "ART" and 'science' {mystery] of SWL Antennas is: * Read & Think * Build & Do * Surprise & Enjoy Afer all, I am simply a SWL and Not On A Power Trip ~ RHF { No Transmitter Required } .. .. TESTING: The receiver for this Test was an Icom IC-R75. http://www.icomamerica.com/products/receivers/r75/ My Matching Transformer "Test Standard" was an ICE 180A. http://www.arraysolutions.com/Produc...age%20Matching My Test Measurement were with "My Ears" and 'My Eyes' (S-Meter). The 'old' Telephone Service Line was a Two Wire (Copper Clad Steel?) Cable. One Wire was used for the ICE 180A and the other Wire was used for the ?Core? Matching Transformer. Question - what is the advantage of using the ICE 180A (1.5-30 MHz) over the 180C (0.1 - 30 MHz)? Is the 180A inherently better suited to SW because it does not need to be so broadbanded? Or will the other work as well, PLUS get you MW? Do these use binocular cores? Or just one of them? I bought the ICE 180A and it seems to work very well down through the AM/MW Broadcast Band (500 kHz) although it's listed Coverage is 1.5 MHz to 30 MHz. The ICE 182A Beverage Matching (Isolation) Unit has a listed Coverage of 100 kHz to 30 MHz. http://www.arraysolutions.com/Produc...age%20Matching As to the Debate about what makes an ICE 180A and an ICE 182A 'different': "IDK" - I DON'T KNOW ! {Did 'mister-know-it-all' Really Say "IDK" :o} .. .. FWIW: Reading your statement about the Binocular Cores, I have just ordered some from Universal-Radio.Com to Test. It is my understanding that One Turn 'counts' for Two when You use a Binocular Core. Now Is That True ? I would love to know this also, and also see a GOOD diagram of how to wire a binocular core. Concerning the 'topic' of Binocular Core Matching Transformers her are a several Links/URLs to take-a-look at: * Multi-Aperture Cores http://partsandkits.com/binocular.html http://www.cwsbytemark.com/CatalogSh...Files/2_34.pdf * Wide Band RF Transformers http://www.electronics-tutorials.com...ansformers.htm * * What are Toroids ? http://www.electronics-tutorials.com/basics/toroids.htm * RF Transformer - Mini-Circuits http://rust.lbl.gov/~gtp/DOM/dataShe.../tranfrmr.html * Inductors: Binocular Balun Cores - Surplus Sales http://www.surplussales.com/FerMisc/FerMisc-5.html * Construction and Use of Broad Band Transformers - Figuer #2 http://www.oselectronics.com/downloa...ansformers.pdf * Amidon #43 & #61 Material Two-Hole or Binocular Cores http://www.amidoncorp.com/aai_woundbeads.htm * Impedance Matching Transformers for Receiving Antennas at Medium and Lower Shortwave Frequencies Bill Bowers - John Bryant - Nick Hall-Patch [VE7DXR] http://www.dxing.info/equipment/impe...ing_bryant.doc http://www.dxing.info/equipment/impe...mer_bryant.doc * Baluns - Kits & Custom - The WireMan http://thewireman.com/baluns.html * Baluns in Theory - RadioWorks http://radioworks.com/nbalun.html * Toroidal Balun Kits, Toroids and Enamelled Wire Packs - OZ-Gear http://www.ozgear.com.au/balun/ToroidalBalunKits.htm * Balun and Transformer Core Selection - Binocular Core Image http://www.w8ji.com/core_selection.htm .. .. Also, I have a SWL 10:1 Balun that is made by "RF Junkie" and will be testing it soon using the same test-set-up. * Two Shortwave Listener (SWL) 10:1 Baluns for Random Wire Antennas http://groups.yahoo.com/group/Shortw...a/message/1523 It is great to see all these fine antenna posts - becoming familiar with the experience of others, and ultimately (hopefully) contributing something that may help others, is the best and highest use of this medium, I think (oh, yeah, that and name-calling over politics ;-) Bruce Jensen iane ~ RHF .. .. |
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