Hi Folks,

Not sure if it helps, but it’s certainly related. A while back I did a simple EagleCAD layout for a microdiplexer (very similar to the diplexer that comes with the Arrow, based on the KI0AG design) that uses 0805 surface mount components. Cost for 3 boards from Osh Park is around $5.00 (not counting the caps/inductors and connectors that would be needed, listed in the BOM).

https://github.com/zleffke/micro_diplexer

There are two variants in the repo, one for edge launch SMA connectors, one for through hole SMA connectors (or coax pigtails if desired). If memory serves, with the components in the BOM, the board can handle roughly 10W of RF or so on TX (though at the time when I built them, my project was RX only….so I haven’t actually tested the TX RF power handling capability). There is also a QUCS simulation in the repo if that’s of interest for folks.

-Zach, KJ4QLP

Research Associate

Aerospace & Ocean Systems Lab

Ted & Karyn Hume Center for National Security & Technology

Virginia Polytechnic Institute & State University

Work Phone: 540-231-4174

Cell Phone: 540-808-6305

From: KENT BRITAIN <wa5vjb@flash.net>
Sent: Thursday, January 14, 2021 10:18 AM
To: amsat-bb@amsat.org; Fred Hillhouse <fmhillhouse@comcast.net>
Subject: [AMSAT-BB] Re: Feeding M2 Eggbeaters

Hi Fred:

All depends on the voltage breakdown rating of the 4.7 and 10 pf caps.

Something like Silver Mica's with 100+ voltage ratings should be good to 100 watts or so.

Some 1000 volt doorknobs, close to a KW.

Regarding your breakdown version. One backpacker made his out of soft wire. He kind of wands it up and stuffs it in his backpack. When he gets to his hilltop, he 'unwads' the antenna and straightens out of elements. Says they are good for about a half dozen waddings, then he makes a new one.

73 Kent WA5VJB

On Thursday, January 14, 2021, 09:07:02 AM CST, Fred Hillhouse <fmhillhouse@comcast.net> wrote:

Hi Kent,

How much power would you expect the design in the PDF to handle?

Note: This is not to imply I am using high power into a satellite.

I made a “break-down” version of the Cheap-LEO. It still needs some refinements, such as shedding weight.

Thank you!

Fred N7FMH

From: KENT BRITAIN [mailto:wa5vjb@flash.net]
Sent: Thursday, January 14, 2021 2:29 AM
To: amsat-bb@amsat.org; Mike Lucas
Subject: [AMSAT-BB] Re: Feeding M2 Eggbeaters

How are his construction skills? Here is the diagram for an easy to build 145-435 MHz

splitter/diplexer. http://www.wa5vjb.com/references/Cheap%20Antennas-LEOs.pdf

Can be built as shown, or in a metal box with connectors.

It would even be possible to locate the diplexer near the antenna, then he would only

have one long coax run. 73 Kent WA5VJB

On Thursday, January 14, 2021, 01:11:11 AM CST, KENT BRITAIN <wa5vjb@flash.net> wrote:

Several companies make a VHF/UHF Diplexer. The 145/435 MHz signals are split in filters.

Kent WA5VJB

On Thursday, January 14, 2021, 01:02:21 AM CST, Mike Lucas <documike@comcast.net> wrote:

Friend of mine just got a M2 Eggbeater SatPack 1setup for VHF/UHF.

His rig covers both bands however only has a PL259 output so he’s wondering how to feed those antennas with one feedline up to the boom. Is there an RF switched coax relay box or something else that will maybe work? I’ve always had radios with 2 RF coax outputs on the radio, then run 2 lines up to the tower & each antenna.

I told him I’d post on here to see what feedback I got.

Thanks

Mike N7ASZ

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