If a T240-43 (good for 100 w) How Many Watts?? for (2 Stacked) .. How Many Watts?? for (3 stacked) How is this Calculated?? (How many Toroid Cores Can be Stacked??)
The highest power capability is to stack three 240-52 mix cores. There is no exact method of calculating this. I have been able to easily run 1500 watts SSB and 1kw cw on 40 through 10 meters. 80 meters is the most stressful and the cores will get hot with over 500 watts. Obviously time is a factor too. I even installed a fan on one for higher power. Don't pay any attention to manufacturer claims. Just build it to the max and do what you can.
If the Drake R-4B tuned Longwave and Meidium wave this radio would be an AM broadcast Dx'er dream radio. This radio has everything on it. The downside of owning a boat anchor radio is finding parts and the techinical skill of maintenance of the radio.
Thankyou for the video. I've just been gifted with one of these, an XA variant, and intend to restore as best I can. Haven't powered it on yet. Any suggestions concerning this rig. de VK2KWW
Nice one. I'm really a hand-mike guy, but dig the old chrome stuff. Someday I'll set up my 104 with the SSB head to see how It works--but golf is my mistress at present.
Hey Steve I looked at your channel description for an email address I'd like to email you my screenshot with the item circled is there any way to contact you? Or you can email me and I return the email 101CarolinaDX at gmail.com
Wait a minute I think it broke a sprinkler line because I see some of that missed directly in the front also of the lower quadrant of the video and it goes away at 3 minutes 16 seconds like the other two plumes
Tell me that looks like smoke If you pause it 2 minutes 34 seconds And stare at this smoke blooms until they disappear at 3 minutes 16 seconds they actually puff twice
WHAT'S in the left side of grass area?? Looks like sprinklers running WHEN tree falls. Mist steam was this a lighting strike?? Two whisps appear from ground I suppose that's very Rudy and undermined maybe when the tree compress the ground and pushed some moisture out through some chipmunk holes or something
My SB-200 runs 600 watts. From what I've seen 500-700 watts is about right. The tubes vary a little as do the meters that we use. They are tough amplifiers that will run a long time. I see some of the RU-vid pests are giving you grief, not to worry. It's the best they can do.
The length should be around 130 feet which will put it on the low end of 80m. Doing that is necessary to make the higher bands fall into place. If you cut it shorter for 75 meters the higher bands will be too high so you need to insert a capacitor at mid point, about 400pf, to raise 80m for the phone band and not affect the higher bands. See my video on EFHW for 75 meters modification.
Steve, tks for the info , my sidetone is pretty rough too, but now after being on for a couple of hours it just stopped ! So I am going to do the mod. Maybe fix that too ,73 K9UT , Tks !
Hi Steve, great experiments. Just a warning regarding the MFJ-854. If you calibrate the MFJ-854 per the manual you would calibrate it on the 1 Amp range, and when you do this the other ranges are not necessarily accurate (lookup table in the manual of meter reading vs current is not correct). I recently calibrated both the original version of the MFJ-854 as well as a more recent version of the MFJ-854 and the both behaved very similar to each other. As an example when you calibrate the MFJ-854 using the 1 Amp range the 300 mA range definitely reads low. As an example on 20 meters using the 300 mA range, a full scale reading of 100 is 352 mA, not 300 mA. A half scale reading of 50 is 192 mA not 150 mA, etc. Not a big deal for relative measurements but it is a big deal if trying to correlate current measurements to antenna modeling predicted values. Today I compared a 20 meter dipole with a 20 meter EFHW mounted 12 feet above the ground using a very good choke on the feedline placed 8 feet from the feedpoint and my center of antenna current measurements almost exactly matched what my 4NEC2 models predicted (and very little difference between the dipole and the EFHW current at the center of the antennas). I use home brew EFHW transformers that are 90 percent efficient and the EFHW antenna with a good choke on the feedline behaves very similar to a dipole when used on the fundamental band. (I normally place my choke 0.05 to 0.06 wavelength away from the feedpoint on the lowest band of operation but in my tests today my choke was farther than normal from the feedpoint because I was using a feedline that I normally use with a 40 meter EFHW antenna and I did not relocate the choke on the feedline) 73, Don wd8dsb
I have one and the brushed brass got a few corrosion stain on it that I couldn't get out. I took it all apart and started with a bench grinder/wire brush wheel. I took the brush grooves out as much as I could the the wire brush wheel. I then went through all of the grit steps, 120/ 150/ 180/ 240/ 320/ 400/ 600/ 800/ 1000/ 1200/ 1500/ 2000/ 2500/ 3000 grit wet/dry sandpaper. I may have skipped a couple grits because of the local availability. Be sure to use a hard flat surface like a 3/ 1/2 inch x 3/4" board. Remember, don't change grits too soon or all you will have is a shiny scratch mark from the previous grit. Work the brass down a make it as shiny as possible. The next steps will really make it a mirror finish. Start with Flitz metal polish. If you use another grit polish, that is ok. Use a piece of paper towel to rub the polish out. Don't let the polish get totally dry before you wipe it off with a clean rag. I used a paper towel because believe it or not, paper towels provide a small amount of grit. Polish it out some and then polish it out many times. Now comes the the final step that will make it a mirror. Use a soft cotton or a microfiber rag. Place the Flitz on it and start rubbing. Use progressively less pressure to the brass each time. Remember don't let the Flitz dry out. It will turn black but that only shows that it is working. The more times you rub it out, the brighter it will shine. Don't stop there, get a piece of aluminum stock somewhere about 1/8 or so thick. I took the plastic key paddles off the key and used them as a template to cut out the aluminum. Repeat the previous steps as needed. You may only have to rub out some minor scratch marks on the aluminum. I counter sunk the mounting holes so I could reuse the same paddle mounting screws again. I added a drop of Gorilla glue to hold the paddles in position. Only use a small dot of glue to prevent it from squashing out. You have now turned a nice Iambic Key into a real show piece. Try not to touch the brass with your fingers because it will want to turn colors in those places. I'm going to see how I can add sometime of protectant like some machine oil or something to keep it from turning dark again. I have a picture of the key on my website in the early stages of building out. It isn't a big picture but you will get the idea. Remember, Don't get impatient and miss a step in the rubbing out process. This is not a weekend project but a labor of love that is well worth it! whitehousecomms-arc.org/continuing-education/morse-code-home/
This is a very helpful video for EFHW. Could you do a test and video like this for the End fed random wire antenna design or give us your guess about how the EFRW design should be configured with respect to counterpoise, choke, and grounding?
If you think about it, there is no such thing as an "end fed random wire". The feed point will never be at the end because there is a counterpoise. The feed point impedance will be determined by the frequency and placement of the feed in relation to the wire and the CP. The counterpoise can easily radiate more than the antenna if the wrong length is chosen. Technically you need a full radial field for proper operation otherwise much RF loss will occur in that CP system. EFRW's are not good antennas but of course you can always make contacts with them and if you're in a contest you'll always get 599.
