Notices by ftg (ftg@mastodon.radio)

Whee!
Been a good while since I bought a new game on release.

Modern internet connections are nice. 160gb game and it takes 1hour to download.

In 2003 it took a day to download Half-Life 2 on my connection.
Had to run it all night and day.

@whitequark @mossmann @LaF0rge
I think it was by Jolly (sadly don't know their mastodon handle, if they have one). Excellent work in any case.

@mossmann @whitequark
And now there is also osmocom-analog, so the network side can also be done. With as little or as much SDR as desired.
http://osmocom-analog.eversberg.eu/

It also supports the 450MHz NMT450 and MPT1327, so no need to try to find a quiet spot on 900MHz either.

@ryanc
I'd say yes, for the 4x4 one.
TX and RX should be the same polarisation for the pair.

@azonenberg @dlharmon @g4dbn
Friend has simulated some stuff relating to that and it seems to simulate up to 20-30GHz with 0.086 semirigid at least.
The thing apparently is to get the launch really good.
So cutting a slot to the PCB for the coax and soldering it to the grounds was apparently critical for good return loss.
Our discussions and his simulations were mostly from the point of feeding LO to homebrew harmonic mixers.
Because I wanted to push 18GHz or preferably 38GHz to a 76GHz rig.

@azonenberg @dlharmon @g4dbn
I'll link this thread to him and ask for input :D

But bending the center over gives an impedance bump and that limits the performance.

The main reason for cutting the slot was get rid of that center conductor to PCB trace bend and impedance bump.

@azonenberg @dlharmon @g4dbn
3/x
- The problems are the same as with coaxial connectors, if the ground path only goes from the bottom of the coax to the microstrips ground plane, the propagation mode of the coax is badly matched to the microstrip.
Some connectors try to mitigate that by having a small "roof" over the center pin solder pad to match the strayfields from the coax end.

Stupidity inbound.
The sheer audacity of building and selling a radar based on a regenerative receiver-transmitter while also selling it as a 2.4GHz one while actually operating on 3GHz turned out to be irresistible in the long term.
So now there's ten of 'em.

#microwaves #RADAR #sband #regen #superregen

@ryanc
Rack pix?
Rack pix!

@jmorris
.086 something maybe?
No wait, that's hardline, not semiflex like this?
RG-40something?!

And agreed, Excellent antennas!
WA5VJB is a wizard pulling such nice performance from FR4.

Whoops.
Apparently we left ping running for about 428million milliseconds.
Amazingly not a single lost packet.

Fixed the radio clubs lab logperiodic.
One of the mat least.
This used to have a badly soldered piece of UT.141 coax on it.
Now it has whatever this thinner flexible stuff is.
And it is soldered properly and an effort was made to keep the transition really short.
Tho likely still crap on 10GHz.

The badly soldered .141 coax broke off one of the radio clubs test antennas. So I fixed it more proper with more appropriately sized coax.
Pigtail used was a random one from the radio clubs "SMA pigtails"-drawer.

Nice antennas with nice and flat gain too.

#ghz_bands #hamradio

@lizakowski
As a stand so that it's not on desk level.
That's more or less it

Absolute dumbest test setup.

#10GHz #ghz_bands

Definitely not the best setup, but enough to show me that this thing covers the upper edge of the 10GHz hamband well.
10.368GHz was a bit in the slope.

Something for the project pile.
This is way too mad to not try at some point.

More than a little bonkers idea and likely not very usable.
But it looks so simple and tempting.

#10GHz #homebrew #microwaves #superregen #RegenReceivers #hamradio

Source article:
https://www.worldradiohistory.com/Archive-DX/VHF-Communications/VHF-COMM.1997.1.pdf

Worldradiohistory.com sure does deserve a lot of love for preserving tons of good ham magazines from back in the day.

73 Hamradio, VHF Communications, "HAM RADIO" and so on.

Yaesu FT-817 at full power on 2m upper sideband.
3kHz RBW, 2Mhz span, max hold and me talking to the mic for a moment.

The spurs look bad, but seem to be -67dBc and -62dBc down.

#hamr #hamradio #yaesu #ft817