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David A copy of your post to the uBITX group has been forwarded to the [email protected]?discussion group.?? This group was formed to move the long and multiple off-topic posts, mostly about EFHW

I’m using one there is almost identical to the one he suggested. Works fine all bands as far as I can tell. I have used boatloads of different ones throughout the years Those that use toroids

Allsison 9 x 50 = 450 12 x 50 = 600 12(impedance ratio)^0.5 = 3.5(turns ratio) 3.5 x 2 = 7 for integer turns 7 turn primary + 2 turn secondary = 9 turns total. 9 turns is compatible with BN-2402 cores

Output of the uBITX is 50 ohms. Your CB SWR meter should work for the upper end of HF range (20M through 10M) and maybe acceptably good for 80M through 10M. Many of those old CB SWR meters were just

Paralleling filters is not a safe thing to do.? Many too many unpredictable things happen. Also the filter impedance is around 500-650 ohms.?? A 9:1 impedance transformer would get you close and

Arv, Its not DC resistance its RF resistance and RF inductance.? Flat conductors are? better for the latter and need to be wider for the former.? That is the wires with RF. The grounds are to the

Re Jerry ..Donno... need to start making some transconductance measurements too anyway ?? I was looking at the gate voltage on the mosfets ..4 V at 100 ma bias ...More swing that +/- 4 volts and

Today I was greatly and pleasantly surprised.? I'd mentioned that I was thinking about converting my BITX20 to 40 meters, and I'd related some stories of frustration with the local ham community

Allison can the "wimpy ground paths" part be helped by overlaying fairly heavy wires in parallel with existing wimpy grounds? Arv _._

Jim, Yes the big thing is developing a voltage across the capacitive gate, takes power to do that. Also the impedance of the source (driver) has to be low at low HF as at 3mhz the gate looks like

There have been many posts regarding end fed?antennas. I hope these posts were helpful.? My favorite portable antenna are?various loops, either full-wave?loops,?quads, or Miniature Magnetic Loop

I appreciate all the support I have received and thanks. I will work on some of these but the whip antenna will not work I'll the magnetic loop antenna. Thanks for sharing. Richard Chan

with 5 ohms and with 100 brightness level , is there no qrm, Junior !!!\ Congrats. sarma vu3zmv [email protected]> wrote:

The nextion 2.8 "display is generating qrm, when I adjust the brightness control to less than 100 I have qrm at the reception, if it is 100 without problems. I installed a 5 ohm resistor in series

Yep?? all true ... minor circuit/device constraints Jim

And a correction to clear up any confusion: I wrote: " Clearly we need these transformers to be impedance matched in the circuit." It should have read: "Clearly we need these FILTERS to be impedance

John It is 7:2 or a 3.5:1 ratio. The impedance ration is the square of the turns ratio. I honestly don't know the answer to your question about paralleling filters. I guess you could try it..... but

I don't think paralleling the filters will impact the nominal input impedance of each filter. If you have a SA and have something to generate a 45Mhz signal you could sweep the filters in parallel and

Should the pad after the balanced modulator be changed to add more loss? That should be easy to do. tim ab0wr "ajparent1/KB1GMX" <kb1gmx@...> wrote:

Warren, Is that a 3.5:1 winding ratio or 3:5? Also to my previous question- does a 1200 ohm impedance filter become 600 ohm if you parallel two of them? I realize it narrows the BW but I've never seen