Sounds fun. I'm in for one for the lake house.....Rick W5RH <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail&utm_term=icon> Virus-free. www.avast.com <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail&utm_term=link> <#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>
On Tue, Dec 29, 2020 at 10:55 AM mark janzer via BVARC <[email protected]> wrote: > If there is enough interest, we could pull together a session for members > to build their own 40m or 80m EFHW antenna, for the BVARC January 23rd > Club Activity morning at the Bayland Park Community Center. The design > would be this (credit to Rick Hiller for the reference): > > 19-End+Fed+Half+Wave.pdf (squarespace.com) > <https://static1.squarespace.com/static/5b1576d036099b603985500c/t/5c5236b57924e85a9a1ccd62/1548891830343/19-End+Fed+Half+Wave.pdf> > > EFHW Antenna --- Building The Transformer - YouTube > <https://www.youtube.com/watch?v=sty7RlXQoJI> > > > The parts are locally sourced (JPM Supply and Home Depot), either triple > or dual core unun (240-43), and the entire assemblage would cost roughly > $60-$70. We'd use the 43 material for the cores, vs. 52 - to reduce the > cost. The 43 cores are readily available from JPM Supply. > Members would reserve ahead (pre-pay via Paypal) once a parts list is > fully generated. > > The antenna parts would be brought to the session, box pre-drilled, and a > nanoVNA would be present for preliminary testing. > > 73 > Mark > K5MGJ > > > On Tuesday, December 29, 2020, 03:21:34 AM CST, Mark Brantana via BVARC < > [email protected]> wrote: > > > Ron > I do have a NanoVNA, and I like the dipole thought. The EFHW design has a > match. Basically a toroid. I will likely experiment with both antennas. > Thank you. 73. > Mark > N5PRD > > Sent from my iPhone > > On Dec 29, 2020, at 1:50 AM, Ron Bosch via BVARC <[email protected]> wrote: > > > And so everyone knows why I am up so darned late, I am waiting for the > 02:22 ISS pass to download a stinking picture since I only have 2 more > realistic shots at doing so :-) > > On Tue, Dec 29, 2020 at 1:43 AM Ron Bosch <[email protected]> wrote: > > Mark, > A few points that I couldn't make on the net, because of time. > 1. I wasn't saying don't do it, just don't expect a bunch of QSO's. You > will be limited to when the band is really open, and the noise floor is low > at the receiving antenna. That will reduce the number of potential > contacts by at least an order of magnitude. That being said, operating > anything is better than operating nothing. > 2. IMHO, and end fed antenna is not a good choice unless you also build a > matching bridge. You can't expect to maintain an exact 50-ohm load from an > end-fed with just a toroid, you also need some shunt resistors, and > variable caps, and such, and you will need to tune it depending on > conditions due to reactance unless you built-in a big enough reactance in > the circuit, and cut the end-fed to exactly 1/2 wave where you want to > operate, and the toroid with that much permeability probably ain't cheap. > A better approach to me would be a 20M 1/2 wave dipole trimmed at operating > height with an antenna analyzer. > 3. Doing this in the city, with the amount of interference, and the > antenna compromises we have to make seems to add a whole other set of > issues to making contacts. If I were to do it, I might plan to take the > rig out of the city to operate it, and get the advantage of using trees and > such to get my dipole at 33 feet up, with a low noise floor to increase my > chances of contacts. > 4. In any event, I suspect you are really going to need at least a Nano > VNA to make sure you don't smoke the finals, since I doubt seriously that a > QRP kit includes protection circuitry. That will add a minimum of $50 to > your build, although you would save a bunch on the antenna if you built a > 1/2 wave dipole instead. Heck, I have an extra 1:1 current balun I can > part with for the rock bottom price of $0.02, and since I am including my > $0.02 in this email, net due is $0.00 :-) > > Ron > KE4DRF > > On Mon, Dec 28, 2020 at 11:44 PM Mark Brantana via BVARC <[email protected]> > wrote: > > I thought I had things all figured out. I originally wanted to get back on > HF, and found I could get some great used equipment for about $400, not > including antenna. Add a 10-80 m antenna from MyAntenna for around $165. I > already have coax installed. Grand total: $565 > > Normally, this cost would not be an issue, but like so many others I am > short on funds due to CV-19, so it is a bad time for this expenditure. I > find I can buy a 20-m QRP Labs CW mini with case for about $90, and build > an EFHW antenna for another $20 (including the matching toroid). Grand > Total: $110 > > Everything has its advantages though. A ham since ’78, that’s 1987, I feel > that > 1. this would force me to improve my almost forgotten code without the > inevitable distraction of voice alternatives, > 2. this would give me a chance to build a full small project and antenna. > > Today, though, some felt that this setup would lead to disappointment on > my part. I am fully aware there will be some limitations to QRP, but the > generally negative comments form our net were as follows: > 1. The band is poor at this time. > 2. The 4-5 Watt QRP would not get in, and even a 100 Watt unit would not > suffice, but needs to be about 500 Watts. This would lead me to need back > to spending at least $565, and more for an amplifier. (So we are now saying > that even a typical 100 Watt radio is insufficient?) (I would also note > that QRP sells a 50 W amplifier for this radio as an add on. > > Experience counts. So, I am looking for my fellow hams with QRP experience > to share their thoughts. I thought I had this all figured out, but if I am > going down a wrong road, I need to know. What has been your experience with > 20-m QRP? > > Mark > N5PRD > ________________________________________________ > Brazos Valley Amateur Radio Club > > BVARC mailing list > [email protected] > http://mail.bvarc.org/mailman/listinfo/bvarc_bvarc.org > > ________________________________________________ > Brazos Valley Amateur Radio Club > > BVARC mailing list > [email protected] > http://mail.bvarc.org/mailman/listinfo/bvarc_bvarc.org > > ________________________________________________ > Brazos Valley Amateur Radio Club > > BVARC mailing list > [email protected] > http://mail.bvarc.org/mailman/listinfo/bvarc_bvarc.org > ________________________________________________ > Brazos Valley Amateur Radio Club > > BVARC mailing list > [email protected] > http://mail.bvarc.org/mailman/listinfo/bvarc_bvarc.org > -- Rick Hiller *e-mail: [email protected] <[email protected]>* *Cell: 832-474-3713* *Physical: 9031 Troulon Drive* * Houston, TX 77036* <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail&utm_term=icon> Virus-free. www.avast.com <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail&utm_term=link> <#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>
________________________________________________ Brazos Valley Amateur Radio Club BVARC mailing list [email protected] http://mail.bvarc.org/mailman/listinfo/bvarc_bvarc.org
