What cores did Laurence use and what wire size & type? Sorry to hear she failed again. Maybe the cores got damaged the other day with no external indications like cracking or? I don't recall you havi
Hi Mike, I don't think that the cores were damaged from the last incident. I was able to run the 250 watt transmitter through it with no problem and no measureable reflected power. I understand that
Contact G0MRF and get some of those big honk'n 58mm 3C90 toroid ( Suitable for tx matching transformer or antenna matching to 800W) £7.80 - Back in stock from 7/Jan/04 We use these and they rock. 73
Hi Warren, an excursion to high temperature should not affect the ferrite as this is sintered at quite high temperatures to make the ring. What might suffer is the epoxy (usually) coating which may b
Hi Scott, The 58 mm 3C90 has smilar permeability to the type 77 I am using but 58 mm is considerably smaller than the 3" cores I am now using. -- 73 Warren K2ORS/WD2XGJ FN42hi http://www.w4dex.com/wd
Hi Alan, I will look at it tomorow as it was too hot to handle today! I don't know if the core is intact or has fractured as it is covered with fiberglass tape. The fiberglass tape has turned yellow
No cooling fan Warren just open "ish" air circulation without it things got a little warm especially at 100F ambient in the summer....I love Okie... Hi Mike, I don't think that the cores were damaged
Hi Laurence, I've thought about leaving the box open but I couldn't do that if there was precipitation of any kind. Also might be hazardous to the neighbor's kids - I haven't seen anyone get near it
Hi Warren, an excursion to high temperature should not affect the ferrite as this is sintered at quite high temperatures to make the ring. What might suffer is the epoxy (usually) coating which may
Hi JB I am almost tempted to say "if it goes rancid you are not running enough power" :-)) Cheers de Alan ferrite as lossy might be well!! Warren, Alan, LFers, From my own experience I wouldn't recom
Yep your absolutely right about safety Warren - Kids, dogs and the local Skunk/squirrel population stayed away but I did notice that the odd California wren had left its mark inside the coupler reduc
Dear Warren, LF Group, Sorry to hear about your problem. The transformer core seems more than adequate for the power level you are using - the flux density in the core at 1.2kW should be about 40mT,
Hi Jim, Thanks for the analysis. The transformer is in a closed weathertight box which I'm sure contributes to the heat build up. The high voltage on the transformer secondary (loop or low impedance
Laurence, Thanks for the information and pictures on your tuner. You certainly had great results and the tuner was very robust indeed. I plan on putting a sign on my tuner as well, something like "Da
...The voltage will be E=I*X, in this case the I is about 30 amps and X is near to 200 ohms so E= 6000 volts. I have seen actual arcing when the spacing or insulation was inadequate... Dear Warren, L
