Tag Archives: Dave Cripe (NM0S)

Kev-Flex Stealth Kevlar Antenna Wire: an incredibly durable wire for field radio

My good friend David Cripe (NMOS) has recently informed me about a new product he’s offering to the radio community via his eBay store: Kev-Flex Stealth Kevlar Antenna Wire. Kev-Flex looks like a superb option for field antennas of all stripes especially since it has an incredibly high tensile strength. It’s available in 75′ bundles, but Dave can also cut custom lengths. NM0S is also a trusted retailer in the ham radio world, so you can purchase with confidence.

Here’s the product description and link:

Kev-Flex is a unique antenna wire manufactured exclusively for NM0S Electronics. The lightweight center core of the wire is made from Kevlar fiber, giving the wire its incredible strength. The Kevlar core is wrapped with six tinned strands of 30 AWG copper. The effective surface of the wire creates an effective skin area capable of handling well over 100W.

The cable is protected from the elements by a coating of UV-resistant black polyethylene. With a total diameter of only 1/16″ (incl. insulation) and a weight of just 16 feet per ounce, the tensile strength 125 lbs allows lengthy unsupported horizontal runs. Kev-Flex is ideal for extremely long LW-antennas and Beverages and is great for balloon or kite-supported antennas. Its low weight and high break-load makes it most suitable for SOTA activations and other field operations.

The outer insulation makes the wire kink-resistant, and its slippery finish makes it ideal for stealth antennas that must be passed through trees or other obstacles without snagging.

This antenna wire is sold in 75 foot long bundles, which is enough for a 40M dipole or EFHW. Two 75 foot bundles would make a great 80M dipole. Custom lengths are available on request.

Specification

– Kevlar fiber core wrapped with six 30 AWG copper strands
– Weather-proof black polyethylene (PE) insulation, 1/16″ O.D.
– Weight: 16 feet per ounce
– Breaking-load: 125 lbs
– Velocity factor 0.97

Click here to view on eBay.

Spread the radio love

Any favorite Soviet era radios?

9 Replies

A vintage radio from Kim Andre Elliott’s collection.

I was just chatting with my buddy Dave Cripe (NM0S) who recently snagged a cool Soviet-era vintage portable radio at ShopGoodwill.com. It’s a beauty:

I’ve always been fascinated with Soviet and Eastern European designs from the 60s, 70s and 80s, but I’ll be the first to admit that I know little-to-nothing about them.

I’m curious if any readers could shed light on some of their favorites makes and models? Are there any exceptional performers? Any that are highly valued? If you have photos, consider sharing them as well. Please comment!

Spread the radio love

Dave sheds a little light on wireless electric transmission

2 Replies

Many thanks to SWLing Post contributor, Dave (NM0S), who left the following comment on our previous post regarding wireless electric transmission:

This company [Viziv] had been known as Texzon until recently, and must have apparently had a recent change of name.

Their main published paper is found here:

Click here to download PDF.

Basically they claim to be exciting a ‘Zenneck Surface Wave’ by using an electrically small antenna, which by virtue of its very small radiation resistance, requires very large currents to radiate power. Their supposition is that these high RF currents injected into the ground propagate with low loss, and can be harvested at some remote location. Presumably, by exploiting the reciprocal nature of antennas, a similar device would be employed to receive this RF power. It is not clear that they will be able to do something beyond what every crystal radio hobbyist has been doing for the past century.

Thank you, Dave! I love the crystal radio analogy.

Spread the radio love

Building the Cricket QRP Transceiver at HOPE 2018

9 Replies

As I mentioned in a previous post, I’m currently at the Circle of HOPE (Hackers On Planet Earth) convention in New York City.

Yesterday morning, I grabbed some breakfast and a cup of coffee then headed to the Hardware Hacking Village–a space in the Hotel Pennsylvania with over 50 soldering stations–sat down and started to build the Cricket QRP transceiver.

I’ve always found that kit building and soldering calms my nerves and since my presentation was later that day, it was just what the doctor ordered.

I opened up the kit at 9:00 am and started working.

All of the components were accounted for and the instructions were clear and easy to follow.

Although I didn’t need extra help I did have the extraordinary luxury of having the kit’s designer, my buddy David Cripe (NM0S), sitting across the table from me at one point.

Dave (NM0S) giving my Cricket the nod of approval.

The Cricket was incredibly easy to build, taking only about one hour or less start to finish.

The cool thing about this transceiver is that there are no coils to wind (they’re traced into the board) and by breaking off a pre-scored length of the circuit board, you can build an on-board hand key.

I had it on the air by 10:30 at the special event station W2H.

The Empire State Building as seen from the roof of the Hotel Pennsylvania.

Unfortunately, the blowtorch AM broadcaster on the Empire State Building (ahem…next door!) overloaded the Cricket in no small way. I was, however, able to confirm output power, audio and that the receiver was functioning.

Most impressed!

Incidentally, Dave tells me he has a limit number of the Cricket kits available on his eBay store for about $37 US shipped, if you’re interested.

Click here to view the Cricket on eBay.

As for HOPE? It has far exceeded my expectations.

I’m looking forward to Chris Fallen’s presentation about HAARP later today, followed by David Cripe’s EMP presentation (who I will introduce).

Spread the radio love

Presentation at The Circle of HOPE conference next week!

7 Replies

Dear Post Readers,

If you live near or are planning travel to New York City next week, I would encourage you to check out the HOPE (Hackers On Planet Earth) conference at the Hotel Pennsylvania (July 20-22, 2018). The location couldn’t be more accessible: across the street from Penn Station and down the block from the Empire State Building.

The HOPE conference is diverse with an incredibly wide range of topics spanning technology, culture and so more. We’re talking about “hacking” in the best sense: those with the technical knowledge and ingenuity to overcome problems and better understand/explore the world around us. HOPE always has a strong contingent of radio enthusiasts as well–many of whom also attend the Winter SWL Fest in Plymouth Meeting, PA.

This will be my first HOPE conference so I’m especially honored to have been selected as a presenter.

HOPE Presentation

My presentation is titled: Creating a Radio Time Machine: Software-Defined Radios and Time-Shifted Recordings–here’s the description:

Since the earliest days of radio transmitting, individuals and organizations have made an effort to record and preserve radio signals in the form of broadcasts and other over-the-air communications, especially those of historical significance. Now low-cost software-defined radios (SDRs) coupled with today’s faster memory-enhanced computers allow us to record not just individual signals from one radio station at a time, but an entire broadcast band – a wide swath of frequencies – all at once. Each recording from a particular day and time can easily contain dozens, if not hundreds, of stations broadcasting and communicating simultaneously. Later, via a software-defined radio application, recordings can be tuned and listened to (decoded) as if they were live. This talk will discuss how you can build your own “radio time machine” which supports such virtual time shifts by utilizing an inexpensive ($25-$100) SDR, and also show how you can – for free – virtually “travel” through recent history on radio archivists’ preexisting radio time machines.

Time & location: Saturday 1900 Booth

My two main goals with this presentation are to bring more radio converts into our hobby by showing how accessible and dynamic radios are today and also to give The Radio Spectrum Archive some exposure.

HOPE Workshop

I’m also excited to co-host workshop with my good friend, David Cripe (NM0S). Our workshop is titled: Build the HumanaLight: A “Green” Lamp from Trashed Batteries–here’s the description:

This mini-lamp developed for use in impoverished regions where there’s no electrical grid is powered by a surprising, but ubiquitous, waste product – the residual energy in depleted (used) AA batteries. Workshop attendees will build a HumanaLight on a high-quality printed circuit board. The kit includes all necessary parts, even a “dead” AA battery! No experience required. There is a $15 fee for the kit, with the proceeds going to the nonprofit organization Ears To Our World, which developed this valuable and important technology.

Time & location: Friday 1900-2030 Hardware Hacking Village (Mezzanine)

No kit building experience is necessary! We’ll help and guide you as you build an incredibly useful tool!

HOPE Radio

In my spare time, I also plan to help with HOPE’s special event amateur radio station W2H. If you can’t attend the event, consider trying to work us on the air! Here are the details:

Amateur Radio Special Event Station W2H and 70cm Repeater

If you’re an amateur “ham” radio operator, you’re part of a hacker community that goes back over a century. Bring your handie-talkie to QSO with the many hams at HOPE to keep up with what’s happening. Visit Special Event Station W2H and operate on several HF/VHF/UHF bands in various voice and data modes to freely communicate with hams around the globe – sans telecom infrastructure! Our 70cm repeater input is 442.875 MHz (PL 167.9) and the output is 447.875 MHz which W2H operators will be monitoring. We also encourage simplex ops on 147.545 MHz and 433.545 MHz (PL 77.0).
More details at http://ham.hope.net.

Time and Location: Friday through Sunday – 18th Floor (next to the 2600 store)

If you can’t tell, it looks like an action-packed weekend! I’m super excited and (admittedly) a little intimidated! Should be lots of fun.

Come join the fun!

Full details can be found at The Circle of HOPE conference website.

Spread the radio love

2018 ARRL Midwest Convention STEM TechFest: August 4 & 5, 2018

The Cricket: The Four State QRP Group’s latest transceiver kit

7 Replies

Here’s a hot tip for those of you who enjoy building transceiver kits:

The Four State QRP group has just released The Cricket: a simple 80 CW transceiver kit. The Cricket was designed by David Cripe (NM0S) who is behind a number of successful kits (including the Ozark Patrol and the Bayou Jumper).

The amazing part about this kit is that it’s super simple, has no toroids to wind and doesn’t even need to be aligned. It even includes a Morse key.

All this shipped for $32.68 in the US, $39.50 in Canada and $43.50 for international orders. A serious bargain, in my book.

Typically, Dave’s kits sell out the same day they are posted for sale. If you’re interested in The Cricket, don’t hesitate to order! (I just bought three, for example.)

Click here to order The Cricket.

Here’s The Cricket kit description via the Four State QRP Group website:

Kitted and Offered For Sale By The Four State QRP Group

The Cricket is a low cost entry level minimalist CW transceiver for the 80 meter band. Chosen as the build session kit for OzarkCon 2017, it bears a family resemblance to the well known but much lower performing Pixie. However it is very different and vastly improved over the Pixie. This is NOT a Pixie, it is far superior! It features low parts count, better components including MOSFETs for better sensitivity and switching, and a modern NJM2113D audio amp.

A TX/RX offset is also incuded so that you can work other stations that have zero beat you, or are using a crystal on the same frequncy. Full QSK and a sidetone complete the essential operating features. Dave’s famous etched spiral coils are included on the pc board, so there are NO TOROIDS to wind. Additionally a straight key is included on the pc board, just snap it off, mount it on the board, and the whole rig is then self contained. Also included is an electronic keyer adapter – you can use your favorite keyer with the Cricket! These are many features for such a low parts count and inexpensive transceiver.

ALL THROUGH HOLE parts make this kit very easy to assemble. It will make a fine, fully functional, and educational first rig for a new builder, the new ham, or seasoned veterans wishing to just have fun with a new rig at minimal expense and effort. Note that Novices and Technicians have 80M CW privileges from 3.525 to 3.600, same as everyone else – so they also can build and use the Cricket.

This simple rig is fun and functional, and made many contacts at OzarkCon after the build session. A proven design and a great choice for your next rig, it is perfect for a group build with nets and contacts after the build. This is an excellent club project.

Spread the radio love