The loop doesn't seem to do much except reduce the performance at the LF end, mainly due to the loss of one half turn. The first set of results is for the balun as shown in the diagram, the second is the same balun with the feedback loop removed and the wire just pulled out of the end where the loop is shown in the drawing. I built a version of the CQ Ham Radio balun design using some small, long, ferrite tube cores, and measured the secondary impedance as before.
So I think even he has never seen the disassembled inside of CHA Your work must be the first ever in the world, at least, which have been published. Through his experiments he tried to assume a structure of CHAB based on Xray photograph of its core unit. He finally made his original MLB antenna. Then he experimented on the MLB deployed broadband antenna again and again. Sorry I can not discribe details of this feature because my technical knowledge is limited. For your reference, let me tell you some additional information.Īccording to his article, MLB is originally developed as a impedance matching transformaer at the passive antenna termial of HF radio.Īlso the transformer has another feature that you do not need an earth side element when you deploy the MLB. I was impressed very much with your disassemble report of CHA You did a great work. As another test I terminated the input with a 50 ohm load and then measured the impedance of the secondary winding with an Autek VA1. The through loss curves when terminated in 50 ohms seem to be very similar to your genuine unit. No additional import charges on delivery.I have now made a copy using 25mm ferrite rings and 15mm copper water pipe as the inner cores. The item you've selected wasn't added to your basket. Seller information nevada-warehouse Contact seller. Learn more - eBay Money Back Guarantee - opens in new window or tab. Get the item you ordered or your money back. Email to friends Share on Facebook - opens in a new window or tab Share on Twitter - opens in a new window or tab Share on Pinterest - opens in a new window or tab. It does a good job, tested at 2 kw no problem, i have not measured the antenna lobes but i thinkit is well symmetrized. The ferrite is a simple receiver rod instead a big toroid! Verified purchase: Yes Condition: new Sold by: nevada-warehouse.
Comet have beefed up the case on this range of high power baluns, the very tough and strong construction should give many years of service! The base connector is the ever popular SO socket.