Tag Archives: Kits

New from Heathkit: the Explorer Jr TRF AM radio receiver kit

The Heathkit Explorer Jr. (Image Source: Heathkit)

Yes, the legendary Heathkit company is back and their first kit is a simple Tuned Radio Frequency (TRF) AM/mediumwave analog receiver: the Explorer Jr.

I knew Heathkit was back in business and under new management, but hadn’t heard any updates as of late. Their president, Andy, just sent a message to the “Heathkit Insiders” group explaining what the team has been up to:

“We’ve designed and developed a wide range of entirely new kit products. We authored the manuals for these kits, complete with the beautiful line art you rely on, preserving and respecting our iconic historic Heathkit style. We developed many new inventions and filed patents on them. We relocated Heathkit, and set up a factory, and a warehouse, and offices, in Santa Cruz, California, near Silicon Valley. We built the back office infrastructure, vendor and supply chain relationships, systems, procedures, operations methods, and well-thought-out corporate structure that a manufacturing company needs to support its customers, to allow us to scale instantly the day we resume major kit sales. All this effort enables us to introduce a fleet of new kits and helps ensure Heathkit can grow, prosper, and continue to bring you great new products for a very long time.”

The Insiders’ message goes into much more detail–I would encourage you to contact Heathkit about joining this group.

The big news in this message was the launch announcement of the Explorer Jr. kit which can be ordered from their website now. The price is $149.95 plus shipping. Heathkit anticipates a 30-day shipping time for the first set of orders.

Here’s a description of the kit from their website:

A Radio Kit Whose Time Has Come.

Again.

When Heath started designing & selling do-it-yourself airplane kits shortly after the Great War, the state-of-the-art in radio was the Tuned Radio Frequency (TRF) design.

A TRF radio was a great deal. If you had a great deal of money. A TRF receiver became a fixture in the homes of families around the world, receiving the news and music AM broadcasts of the day. A family AM radio was a big investment — $100 to $625 in 1929 dollars. (With inflation, that’s $1,400 to $8,700 in today’s dollars.) Of course, at that price radios also were beautiful. They were made of fine wood, and designed to last. Radios were a visible and attractive furnishing you could be proud to have in your living room or parlor.

Heathkit’s TRF radio is a great deal. And a great deal of radio. This Explorer Jr^TM radio is modeled on the original TRF designs, but better. You get to build it yourself. It’s safe and simple enough for beginners to assemble and understand. But it receives AM broadcast stations with performance superior to the vintage radios of 1930.

With the number of Heathkit enthusiasts out there, I suspect this first run of kits won’t last long. The kit trim is available in six colors: Silver, Cranberry, Cucumber Green, Plum Pie, Sapphire Blue, and Tangerine.

Click here to view and order the Explorer Jr on Heathkit’s webstore.

Spread the radio love

National RF 75-NS-3 receiver kit

9 Replies

National RF, of California, has introduced a new “semi-kit” receiver: the RF 75-NS-3. Here’s an excerpt from the product description page of the National RF website:

National RF’s 75-NS-3 receiver is a complete super-hetrodyne mini high frequency receiver, designed specifically for the short-wave listener, electronics enthusiast or radio amateur, who wants to use their hands and build a radio. The receiver is offered as a semi-kit in which the electronic assembly is loaded and functionally tested at the National RF facility. The customer must then go to the grocery store (yes…the grocery store!), procure a can of [Spam] lunch meat, eat it or give it to the dog, and then proceed to drill and paint the can, in order for it to become the receiver’s enclosure! […] Detailed drilling instructions and final assembly instructions are provided as part of the kit. All other parts required for completion of the receiver are provided as well. Recognizing that the finished assembly looked somewhat like the fabled Collins receiver of the ‘60s, the 75S-3, (particularly when the can is painted a light gray) National RF engineers dubbed it (with tongue firmly planted in cheek, of course) the 75-NS-3! Although we have had fun packaging this receiver in a lunch meat can, it is nothing to turn your nose at! Its performance and portability will surprise you, and it is an ideal radio to bring with you on any trip!

The receiver architecture is that of a single conversion super-hetrodyne receiver, that is capable of receiving AM, SSB, or CW. The receiver incorporates a dual gate FET as an RF amplifier with manual peaking and gain controls. A ceramic filter is used in the IF section with a front panel switch that controls a broad or narrow IF response. Other front panel controls include audio drive, BFO setting, and a band switch for the HF bands. The 75-NS-3 has internal receive frequency coils that are switched at the front and rear panels. The frequency range of the receiver, over three band set positions, is 3.5 through 12 MHz. This allows reception of several international short-wave bands, the 80, 60, 40, and 30 meter amateur radio bands, and of course, WWV time and frequency standard stations at 5 and 10 MHz.

For those who simply want a lower cost receiver to monitor the shortwave frequencies, National RF offers two variants of the original receiver: the 75-NS-1 and the 75-NS-2. Both are based on the design and circuit of the 75-NS-3, but do not have the band switching and frequency range of the 75-NS-3 receiver. The 75-NS-1 covers between 3 and 6 MHz, including the 80 and 60 meter amateur band. The 75-NS-2 covers between 6 and 12 MHz, including the 40 and 30 meter amateur bands. Both units have the fixed ceramic resonator band width set for about 6 KHz. And, of course, they are both designed to fit in the tasty potted meat can!! All other specifications presented apply to both of these models as well.

Pricing of the 75-NS-x versions:

Type 75-NS-1 Mini HF Receiver Semi-kit (covers 3 to 6 MHz) $189.95
Type 75-NS-2 Mini HF Receiver Semi-kit (6 to 12 MHz) $189.95
Type 75-NS-3 Mini HF Receiver Semi-kit (band switched from 3.5 through 12 MHz in three switched positions) $269.95
Shipping and Handling to within the US $10.00 each

Click here to view on the National RF website.

Spread the radio love

Video: Stephen’s Poldhu Radio Kit

Neil’s updated radio kit guide

2 Replies

My Ozark Patrol regenerative receiver kit

Neil Goldstein, W2NDG, has just informed me that he’s updated his comprehensive radio kit guide which can be found at RadioKitGuide.com. Many thanks, Neil!

The next kit I have on the table is the Sawdust Regenerative Receiver by BreadBoard Radio. Should be a lot of fun and a nice weekend project (once I have a free weekend to complete it). Still, I think I’ll check out Neil’s list to see if there are any new kits I’ve overlooked–after all, fall and winter kit-building seasons are just around the corner!

Spread the radio love

New Franzis shortwave radio kit

5 Replies

Many thanks to SWLing Post reader, Franz Miller, who writes:

“I’ve pasted a link below to the webpage at Conrad in Germany for yet another Franzis radio kit; no idea how good it is, but it looks neato-retro to me. Covers longwave, medium, shortwave VHF, & UHF, allegedly. Price on Conrad’s website is around 69 Euros.”

Click here to view the new Franzis Radio Kit on Conrad’s website.

I truly appreciate the reminder, too, that I have a previous model Franzis kit somewhere in storage that I need to unearth and build! I assume this new Franzis model also has a cardboard chassis.

Update–Tomas adds the following comment:

Here is a link to the Franzis site where there are several pictures and also a two minute video demonstrating the kit.

http://www.franzis.de/elektronik/lernpakete-elektronik/der-grosse-franzis-radiobaukasten#

Of course, for SW it only supports the 41-meter band.

Spread the radio love

Crystal radio credit card receiver

12 Replies

On a tip from my good friend Dave Cripe (NM0S), I just purchased this cute crystal receiver kit from a UK-based seller on eBay.

The price is 8 GPB plus 3.50 GPB for shipping. After PayPal currency conversion, I paid $17.63 US shipped from the UK–a very fair price. The kit is supplied with 5 meters of antenna wire, a high impedence earphone fitted with crocodile clips, and two double crocodile clip leads. Each unit is also tested prior to shipping. The seller also has a 100% positive rating on eBay.

I’ll certainly make a post about the radio once I receive and build it. While there aren’t as many blowtorch broadcast stations to hear these days via a crystal set, with an ample length of antenna wire, you may be surprised what you will hear. Certainly a fun and lightweight item to take camping or place in your bug out bag. No batteries required!

Update: Since making this post, it appears the item number has changed since the seller had to list a new lot of kits. Below, I’ve made two links that search eBay based on the description, not item number:

Search via eBay US (best if you’re in the USA, but scroll to bottom of screen to see this item under “International Sellers”)
Search via eBay UK (best if in UK or EU)

Spread the radio love

Guest Post: Anil reviews the FiFi-SDR receiver kit 2.0

9 Replies

Many thanks to SWLing Post reader, Anil Raj, for sharing his review of the FiFi-SDR receiver kit 2.0:

The perfect radio for business travellers?

I travel regularly, or should I say commute between Europe and Asia, and have been on the lookout for a small receiver with good performance that would be easy to carry with me. I never travel without my laptop so an SDR would be the sensible thing to look for. A few weeks back the tiny FiFi SDR receiver caught my interest as I was browsing the website of Funkamateur http://www.box73.com/ the excellent German ham radio magazine. It looked promising as it had an impressive bank of filters covering all the way from LF to HF. Also, the front end is designed to emphasize sensitivity, so that it can work well with short wire antennas. It also had a built in sound card which would make interfacing to my computer a simple job.

The price was certainly right – $ 169. I ordered it, and it showed up in my mailbox a few days later. It is offered as a “kit” though in practice all that needs to be done is to solder a couple of connectors and sockets. All the surface SMD components are pre-soldered, and the rugged extruded case has die cut holes for the connectors and controls making the mechanical assembly very simple. The entire exercise took me about 20 minutes until the receiver was plugged in and powered up.

Since I use a Mac the choice of SDR software is a lot more restricted than that for Windows. I did however find free software called SDR Radio (http://dl2sdr.homepage.t-online.de/) developed by DL2SDR which does a great job of partnering with the FiFi and my Mac.

SDR Radio is still in development, so the UI can a bit rough at the edges at times. Also, configuring the Audio and MIDI settings on my Mac took a bit of work, but DL2SDR Sebastian was quick to reply to my mails requesting help when I got stuck.

So how does it all sound? While I am sure that there may be better performing SDR radios out there, what this little matchbox sized receiver does is simply amazing. Users running Windows will have access to much more sophisticated applications than the simple programs available for Mac and will be better able to compare this radio. However, it does an outstanding job of handling both AM broadcast as well as CW and SSB utility and Ham signals. While SDR Radio does not offer a lot of bells and whistles at present, the continuously variable bandwidth which can be dialled in to almost zero, and effective notch filter get the job done very well. In empirical testing and comparisons with the Palstar R30C, the FiFi easily outclassed the older analog radio (and the Palstar is no slouch, especially on the lower frequencies).

In summary, this is going to be the radio that I will be taking with me on all my travels from now on. It is tiny, ruggedly built, and has excellent RF performance, especially at lower frequencies.

Many thanks for your review, Anil!

The FiFi SDR does indeed sound like an ideal SDR for travel. Like you, I am usually limited by the SDR applications available on the Mac OS. While I use a Windows 7 PC at home, on the road, I travel with the MacBook Air (a superb laptop!).

Click here to view details and purchase a FiFi SDR ($169 shipping included).

Spread the radio love