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How can I make a simple antenna trimmer?
I have an old boatanchor, a Lafayette HE-10, that takes a single wire
antenna and a ground. I would like to make a simple trimmer to optimize the 75 feet of random coated wire. The wire is copper, Radio Shack. Thank you, Bob Grimes |
How can I make a simple antenna trimmer?
sctvguy1 wrote:
I have an old boatanchor, a Lafayette HE-10, that takes a single wire antenna and a ground. I would like to make a simple trimmer to optimize the 75 feet of random coated wire. The wire is copper, Radio Shack. Thank you, Bob Grimes If you mean a simple means of shortening the wire to a resonant length, simply roll the end of the wire into a ball, no special winding or anything, just like a ball of twine. This method is often used as a counterpoise on some of the multiband whips where a ground is not handy. B&W make one, and so does MFJ. You can download their manuals and read what I have just described. I have used a homebrew look-alike to the B&W AP-10 which uses the same method for the counterpoise and it worked well. And you don't have to cut the wire. As well, you can roll or unroll the ball to adjust the length for different frequencies. In an emergency you just take it off the ground end and connect it to the antenna -- it works! Simplest and cheapest antenna system you can imagine! The ball of extra wire acts like a choke and has no real effect on anything other than to effectively shorten the wire. Hope this helps! Irv VE6BP |
How can I make a simple antenna trimmer?
On Thu, 5 Nov 2015 02:28:05 -0000 (UTC), sctvguy1
wrote: I have an old boatanchor, a Lafayette HE-10, https://www.google.com/search?tbm=isch&q=lafayette+he-10 http://www.radiomuseum.org/r/lafayette_he_10he1.html https://www.youtube.com/watch?v=Lk1dmQEsoIk Made by Kenwood/Trio for Lafayette. that takes a single wire antenna and a ground. I would like to make a simple trimmer to optimize the 75 feet of random coated wire. The wire is copper, Radio Shack. I can't tell what it uses for an antenna input (50 ohms, 75 ohms, 300 ohms, broadband, narroband, tracking filters, whatever) so I can't offer an antenna tuner design. Any idea what's behind the antenna connector? -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
How can I make a simple antenna trimmer?
On Wed, 04 Nov 2015 20:10:35 -0800, Jeff Liebermann wrote:
On Thu, 5 Nov 2015 02:28:05 -0000 (UTC), sctvguy1 wrote: I have an old boatanchor, a Lafayette HE-10, https://www.google.com/search?tbm=isch&q=lafayette+he-10 http://www.radiomuseum.org/r/lafayette_he_10he1.html https://www.youtube.com/watch?v=Lk1dmQEsoIk Made by Kenwood/Trio for Lafayette. that takes a single wire antenna and a ground. I would like to make a simple trimmer to optimize the 75 feet of random coated wire. The wire is copper, Radio Shack. I can't tell what it uses for an antenna input (50 ohms, 75 ohms, 300 ohms, broadband, narroband, tracking filters, whatever) so I can't offer an antenna tuner design. Any idea what's behind the antenna connector? It is just a simple old screw, made for a copper wire antenna, the radio was made in the late 50's. I used to have one that I made out of a variable capacitor and just tuned the knob to trim the antenna. I am now 64 and that was when I was in junior high school? Can I get a variable capacitor for an old radio and connect the two ends? |
How can I make a simple antenna trimmer?
On Thu, 5 Nov 2015 04:49:49 -0000 (UTC), sctvguy1
wrote: On Wed, 04 Nov 2015 20:10:35 -0800, Jeff Liebermann wrote: On Thu, 5 Nov 2015 02:28:05 -0000 (UTC), sctvguy1 wrote: I have an old boatanchor, a Lafayette HE-10, https://www.google.com/search?tbm=isch&q=lafayette+he-10 http://www.radiomuseum.org/r/lafayette_he_10he1.html https://www.youtube.com/watch?v=Lk1dmQEsoIk Made by Kenwood/Trio for Lafayette. that takes a single wire antenna and a ground. I would like to make a simple trimmer to optimize the 75 feet of random coated wire. The wire is copper, Radio Shack. I can't tell what it uses for an antenna input (50 ohms, 75 ohms, 300 ohms, broadband, narroband, tracking filters, whatever) so I can't offer an antenna tuner design. Any idea what's behind the antenna connector? It is just a simple old screw, made for a copper wire antenna, the radio was made in the late 50's. I used to have one that I made out of a variable capacitor and just tuned the knob to trim the antenna. I am now 64 and that was when I was in junior high school? Can I get a variable capacitor for an old radio and connect the two ends? I'm 67 and know the feeling. The lab that I patiently built up over the last 40 years is now considered a test equipment museum. Yes. Just a small 365pf(??) or lower value variable capacitor should work. I wanted to see the circuitry so I could provide a better guess at the capacitor value. Something like these: http://www.ebay.com/sch/i.html?_nkw=365+pf+variable Any old tube or xsistor radio should have one. Dig around at thrift shops or ham flea markets for old radios and junk boxes. Good luck and I'm amazed that such an old radio still works. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
How can I make a simple antenna trimmer?
"Jeff Liebermann" wrote in message
... I'm 67 and know the feeling. The lab that I patiently built up over the last 40 years is now considered a test equipment museum. As for my PAL TV cross-hatch-and-dot generator :-( |
How can I make a simple antenna trimmer?
On 11/5/2015 5:06 AM, gareth wrote:
"Jeff Liebermann" wrote in message ... I'm 67 and know the feeling. The lab that I patiently built up over the last 40 years is now considered a test equipment museum. As for my PAL TV cross-hatch-and-dot generator :-( And my Boonton 260A Q meter, (mid to late 50's). Still well functioning though! Mikek |
How can I make a simple antenna trimmer?
On Wed, 04 Nov 2015 21:47:18 -0800, Jeff Liebermann wrote:
Yes. Just a small 365pf(??) or lower value variable capacitor should work. I wanted to see the circuitry so I could provide a better guess at the capacitor value. Something like these: http://www.ebay.com/sch/i.html?_nkw=365+pf+variable Any old tube or xsistor radio should have one. Dig around at thrift shops or ham flea markets for old radios and junk boxes. Good luck and I'm amazed that such an old radio still works. I had it recapped and fully restored by an old ham friend. He even wired it for an Heathkit Q-Multiplier. Really comes alive on the AM band at night! |
How can I make a simple antenna trimmer?
On Thu, 5 Nov 2015 07:57:15 -0600, amdx wrote:
On 11/5/2015 5:06 AM, gareth wrote: "Jeff Liebermann" wrote: I'm 67 and know the feeling. The lab that I patiently built up over the last 40 years is now considered a test equipment museum. As for my PAL TV cross-hatch-and-dot generator :-( And my Boonton 260A Q meter, (mid to late 50's). Still well functioning though! And my WWII-era BC-221 freq meter -- still in use. Together with my Millen 90651 Grid-Dip Meter -- the 1950 model with the 955 acorn tube -- still in use. Jonesy -- Marvin L Jones | W3DHJ | W3DHJ | http://W3DHJ.net/ Pueblo, Colorado | @ | Jonesy | __ 38.238N 104.547W | jonz.net | DM78rf | 73 SK |
How can I make a simple antenna trimmer?
In article ,
Jeff Liebermann wrote: It is just a simple old screw, made for a copper wire antenna, the radio was made in the late 50's. I used to have one that I made out of a variable capacitor and just tuned the knob to trim the antenna. I am now 64 and that was when I was in junior high school? Can I get a variable capacitor for an old radio and connect the two ends? I'm 67 and know the feeling. The lab that I patiently built up over the last 40 years is now considered a test equipment museum. Yes. Just a small 365pf(??) or lower value variable capacitor should work. I wanted to see the circuitry so I could provide a better guess at the capacitor value. Something like these: http://www.ebay.com/sch/i.html?_nkw=365+pf+variable Any old tube or xsistor radio should have one. Dig around at thrift shops or ham flea markets for old radios and junk boxes. Good luck and I'm amazed that such an old radio still works. There's a manual and schematic for the HE-10 (apparently a Globe-Trotter 9R-4J) at the BAMA.EDEBRIS.COM site. It looks as if you can use either an unbalanced random-wire or zep antenna (connect to A1, jumper A2 to E, and connect E to a good ground), or a balanced doublet (remove the jumper, connect antenna to A1 and A2). In either case, A1 and A2 feed into the front-end preselector, which has a 2P4T switch (one position per band) connected to four sets of tuned transformer couplers. The signal goes into the primary of one transformer, out through the (tuned-per-band?) secondary, and then goes to the grid of the first tube via a 250 pF cap. One of the tuning-capacitor gangs is connected to the secondary/gate feed as well. |
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