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QRPp outing

Posted: Sat Jul 06, 2024 8:38 pm
by N8TGQ
I finally got out to the park for first time this summer. I only had my homebrew QRPp rig, an EFHW cut for 40m and a 9 v battery.
I did work one of the 13 colony stations, but everything else was just hits on the RBN.

I need to get out with the analyzer and find the other
06072024 qrpp.jpg
06072024 qrpp.jpg (54.15 KiB) Viewed 4973 times
resonant points on this new wire.

Re: QRPp outing

Posted: Tue Jul 09, 2024 8:23 am
by Andrew (grayhat)
Hi Rick !

A suggestion, if you feel versed to run a little experiment, put it up vertical and connect one or more counterpoise wires with a lenght of 1/16 Lambda connected to the 49:1 "ground" post and laid on ground, in theory the HW won't need it, in practice the wires will improve the radiation efficiency a bit and the vertical setup will lower the takeoff angle, again, if you want, give it a try

Also, and since I'm at it, here's an idea for an "alternative antenna"

https://en.wikipedia.org/wiki/HB9XBG_Antenna

https://oe1iah.at/Hardware/Antennen/HB9XBG.pdf

:D

Re: QRPp outing

Posted: Tue Jul 09, 2024 8:30 pm
by KL7MJ
Why would you prefer the HB9XBG over an EFHW? The EFHW is resonant on all multiples where the HB9XBG is only resonant on odd multiples (as far as I can tell), but they are the same length (1/2 lambda).

Re: QRPp outing

Posted: Tue Jul 09, 2024 8:50 pm
by Andrew (grayhat)
KL7MJ wrote: Tue Jul 09, 2024 8:30 pm Why would you prefer the HB9XBG over an EFHW? The EFHW is resonant on all multiples where the HB9XBG is only resonant on odd multiples (as far as I can tell), but they are the same length (1/2 lambda).
check the radiation pattern (and the gain)

Re: QRPp outing

Posted: Fri Jul 12, 2024 12:01 pm
by N8TGQ
With this setup, my big goals are simplicity and very small size. I want everything to fit into an old eyeglasses case, including the antenna. I want
to pull it out of my pack and be on the air in minutes. And it needs to pack up in minutes.

I'll find the resonant points on the wire and put knots there so I can wind the wire out to just that length. A real "manual" antenna tuner!

The battery and key will be permanently mounted, so nothing can be lost or forgotten. The whole thing will be easy to carry and ready to go
whenever and where ever. I'd like the low-pass filters to be onboard also, but the switching gets to be big and messy

I also have the Zachtek flea transmitter that I could use. It has variable tuning, and the low-pass filters on board, but it only does 20, 30 and 40
meters. The antenna for it would be very simple. It won't quite fit in the eyeglass case either. It would be great if it did 40, 20 and 15. One antenna for everything and no links or traps.

Verticals means messing with masts and counterpoise wires. That means more work and time. I'm trading some efficiency for convenience and weight.

Re: QRPp outing

Posted: Fri Jul 12, 2024 12:08 pm
by Andrew (grayhat)
N8TGQ wrote: Fri Jul 12, 2024 12:01 pm Verticals means messing with masts and counterpoise wires. That means more work and time. I'm trading some efficiency for convenience and weight.
Not in this case, no counterpoise, maybe you'll need to re-read how the antenna is configured; then the "mast" may be a telescoping fishing rod which isn't difficult to carry, but then, by the way, it all depends from what one wants to achieve and also from the will to build and experiment stuff, instead of just buying "ready made one" and plugging it

Re: QRPp outing

Posted: Mon Jul 15, 2024 9:51 am
by N8TGQ
The whole setup, except for the LPF is home brew. Antenna, radio, crystal switching board, even the key. My goal was to show what I was doing.
I wasn't asking for suggestions to improve it or to build my own stuff. I can look up internet posts and repost them also, but I would much rather see what you're DOING.

OXO Setup 09302023.jpg
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