Microwave Folks?

[Jay Francis]

Hi All,

I’m starting to experiment in the higher bands (2.4GHz and up).  I’m kind-of a club lurker and don’t know too many people.  Who else is working in microwave?

I just tried my hand at a bench top downconverter from 10GHz to 500MHz using Mini-Circuits modules and test equipment I already owned.  Nothing amazing… just baby steps and confidence building.

https://youtu.be/bROYiJ-PLFo

And now that I have confidence in generating a 10GHz signal, I’m experimenting with a cheap LNB from Amazon.  The specs say it goes to 10.7GHz, I have bench tested it down to 10.0GHz (LO is 9.75GHz).

https://www.amazon.com/gp/product/B0117BHDHS

Next planned step is to change my bench top downconverter to an upconverter, use the LNB as the downconverter (what it was designed for), and use a ADALM Pluto SDR as an IF transceiver.

–Jay, KA1PQK

[Jay Francis]

Success!

Used the ADALM Pluto as an IF transmitter at 250MHz., LO for the mixer at 10.0GHz, output RF at 10.250GHz

LNB down converts 10.250GHz to 500MHz.  Used my spectrum analyzer as an IF receiver at 500MHz.

Sent and received my callsign via NBFM modulated CW with the SDRangel software controlling the Pluto.

Reference links:

ADALM-Pluto SDR transceiver (can be modified in firmware to work down to about 70MHz)

https://www.analog.com/en/design-center/evaluation-hardware-and-software/evaluation-boards-kits/adalm-pluto.html#eb-overview

SDRangel – SDR software for receive and transmit

https://github.com/f4exb/sdrangel

[Nashua Area Radio Society]

Very cool Jay!
I just built a Langstone SDR – basically a Pluto with a Raspberry Pi4 and touchscreen:

https://wiki.microwavers.org.uk/Langstone_Project

I have some band pass filters and a broadband power amp, I plan on using it for 222, 902, 1296 and 2.3GHz

73 Warren K2ORS

[Jay Francis]

Hi Warren,

The Langstone looks like it will make an excellent rig/microwave exciter.  Thanks for the link – I hadn’t considered using the harmonics of the Pluto for higher frequencies, and you definitely sent me down a series of link rabbit holes 😉

I know a lot of people use the FT817 as an IF rig, and that was going to be part of my plan for portable, but using an SDR like the Pluto can open up so many more possibilities.

Please post updates and pics as you make progress, and if you need someone on the other end of an air gap for a QSO, let me know.  I have some 2.3GHz accessories (antenna/bandpass filter/LNA) and could cobble up a low power transceiver using the Pluto.  QRP on the other bands you mentioned would just take a few mouse clicks 🙂

73,

Jay

 

 

[Jay Francis]

Reviving an old thread… 🙂

I’m still playing with microwave stuff, have signed up with Northeast Weak Signal Group, but am wondering if any local NARS folks are experimenting with or operating the microwave bands?

–Jay, KA1PQK

[Bill Barber]

North East Weak Signal Group will be active on 10 GHz for the ARRL Test from Mt. Washington, Kearsarge, Mt. Equinox, Cape Cod, and Martha’s Vineyard on Sept. 16 and 17.

Also, here’s an associated New England webpage:

http://w1ghz.org/10g/10g_home.htm

73,

Bill, NE1B

[Jeff Millar]

I will be on Mt Greylock in Western Mass this weekend for the September VHF/UHF contest.   The W2SZ group operates 50, 144, 222, 432, 903, 1296, 2304, 3456, 5.6 GHz, 10 GHz, and 24 GHz.

https://w2sz.org/mgef/

Visitors, guest operators, and/or grunt labor welcome and appreciated.

Setup Thursday, Friday Saturday, Operate Sat and Sun, take down Monday

jeff, wa1hco

[Bryan King]

I’m game. I have a 10Ghz transverter and can setup on a local mountain (Uncanoonuc).

73,

Bryan

[Jay Francis]

Bill – Thanks – I’ll have to visit one of those locations (probably Kearsarge is the easiest).  I haven’t seen anyone posting about Pack Monadnock – any idea if it will be used?

[Jay Francis]

Jeff – Very cool!  Looks impressive!  Don’t think I’ll make it over there this time.  Will keep it in mind for the future.  Have fun!

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