Glen has been a master tinkerer in electronics all of his life and I have found him to be a go to Elmer when I wanted to know something about something.  Recently he approached me to see if the CCRA would mind posting some of his thoughts and links regarding Software Defined Radio (SDR).    I jumped at the offer and have copied what he sent to me.  My hope is he will update his information and continue to share his knowledge with us in the future.

Glen, NO6W writes…
At the moment, I’d be happy to have people be able to click links to those two FB photo albums that I included last time….
download and steal for use anything you want from there.
“new radio”
“Software Defined Radio — the toolbox”
In answers to many questions about where I got all that stuff, I put together a list.
I’d really like a link to send people to, for this information.
I’m going to copy it here, and edit it for currency…
I love the global nature of this small-supplier RF community.
I have a magnetic loop antenna amp kit from Bulgaria.
An FM notch filter from Greece.
An RTL-SDR dongle from Amazon.
An SDR that was designed in the U.K., manufactured in ShenZhen, China, and sold through a U.S. distributor in Pennsyulvania..
Parent developer in U.K.
Good source for technical details
manufacturer in China:
You can buy direct if you want to deal with shipping delays:
U.S. distributor.
Ships via USPS Priority Mail and is very fast:
These latest items (below) come from Ukraine, ShenZhen, and Hong Kong…
Most of these will take a couple of weeks to get here.
RF bridge (board could be had for $14 shipped; I opted for the enclosure version for a bit more)
Similar bridges can be searched for here:
BG7TBL RF noise source, with acrylic enclosure
Similar RF noise generators can be searched here:
12V 3A power supply ($3.86 USD each, ordered two)
Many other 12v wall warts can be had.  These noise generators take very little current.
DC-4GHz RF attenuator: 0 – 10 – 20 – 30dB
DC-4GHz RF attenuator 0 – 6 – 40dB
SMA male to SMA male, RG316 jumper, 20cm (lot of ten for $12.88)
AM Broadcast band blocking filter
FM broadcast band blocking filter
[these are useful for the cheap dongle SDR’s which are deafened by strong local stations]
USB cables are notorious for bringing unwanted noise into the cheap, poorly shielded SDR dongles.
clip-on ferrite beads, 10 pack, choose your size for less than $10USD
USB extension cable.
I’ve had a few of these for over two years,
and the sheaths are still pliable,
unlike the Chinesium plastics that stink and then go brittle.
I have an equivalent but discontinued USB desktop charger
that works very well. as a 5v supply, phone charger,
or power source for a wide variety of devices.
Mine has been in continuous use for recharging, stuff for two years.
The grand-daddy site for information about using the cheap SDR dongles continues to be:
It is a very good introduction to the lowest monetary threshold for thrashing with this technology.
There are dozens of applications that have been well documented on its pages.
Everything from following trunking public safety networks, to network analysis.
They also sell, through Amazon, a very useful set of dongles, adapter cables, and many other accessories.
They are really a one-stop shop; a great starting point.
And they have also become reviewers of the next-level SDR radios, the ones going for a couple hundred dollars.
Their comparison articles are excellent..  Their examination of the AirSpyHF+ is what tipped me over into buying one.
Well, there it is, Steve.
I have had non-ham technical friends ask, as well as mostly the ham radio community.
I think we are marketing true gateway drugs here.

Serving the SF Bay Area since 1977