Tag Archives: Radio Kits

Steve builds a DC30B QRP Transceiver

DC30B QRP Transceiver ProjectMany thanks to SWLing Post contributor, Steve (KZ4TN), who shared the following guest post originally on QRPer.com, but I’ve posted it here as well because I’m sure it’ll resonate with those of us who love building kits!:


DC30B QRP Transceiver Project

by Steve Allen, KZ4TN

I wanted to build a lightweight backpackable transceiver I could take hiking and camping. I chose the 30 meter band as it is specific to CW and the digital modes. I am also in the process of building Dave Benson’s (K1SWL) Phaser Digital Mode QRP Transceiver kit for the 30 meter band. Also, a 30 meter antenna is a bit smaller than one for 40 meters and the band is open most anytime of the day.

I sourced the DC30B transceiver kit, designed by Steve Weber KD1JV, from Pacific Antennas, http://www.qrpkits.com. It appears that they are now (10-11-20) only offering the kit for the 40 meter band. The following information can be used for the assembly of most any kit that lacks an enclosure.

Lately I have been finding extruded aluminum enclosures on Amazon.com and eBay.com. They come in many sizes and configurations. I like to use the versions with the split case which allows you to access the internal enclosure with the front and rear panels attached to the lower half of the enclosure. Most of these enclosures have a slot cut into the sides that allow a PCB to slide into the slots keeping it above the bottom of the enclosure without having to use standoffs. The one requirement for assembly is that the PCB needs to be attached to either the front or rear panel to hold it in place.

DC30B QRP Transceiver Project

As the enclosure is anodized, I didn’t want to rely on the enclosure for common ground. I used a piece of copper clad board that I cut to fit the slot width of the enclosure and attached it to the back panel. I was then able to mount the transceiver PCB to the copper clad board with standoffs. This basic platform of the enclosure with the copper clad PCB provides a good foundation for any number of projects. All you have to do is mount the wired PCB on the board, install the components on the front and rear panel, then wire it up.

DC30B QRP Transceiver Project

I wanted to have the choice of a few frequencies to operate on so I searched eBay for 30 meter crystals and found a source for 4 different popular frequencies. I installed a rotary switch on the front panel and added a small auxiliary PCB with two, 4 pin machined IC sockets. This allowed me to plug the crystals into the sockets. I wired the bottom of the socket PCB first using wire pairs stripped from computer ribbon cable leaving extra length. I marked the wires with dots to indicate which sockets each wire pair went to so I could solder them onto the rotary switch in the correct order. It was tight but I always work with optical magnification so I can see exactly what I’m doing. I have used this crystal switching method in the past with good success.

DC30B QRP Transceiver Project

DC30B QRP Transceiver ProjectThe rest of the assembly was straight forward. I find that most kits are well designed and documented, and if you take your time and follow the directions carefully all should go well. The two most common speed bumps seem to be soldering in the wrong component or bad soldering technique. I double check all component values and placements prior to soldering, and I always use optical magnification while working. I inspect each solder joint and look for good flow through in the plated through holes, and make sure there are no solder bridges.

DC30B QRP Transceiver Project

DC30B QRP Transceiver ProjectThe finished product. I bought a Dymo label maker and it works very well for projects like this. I love using these enclosures and they are a leap forward from the old folded aluminum clam shells I used in the past. I could stand on this without causing any damage. Power out is 1-3 watts depending on the DC power in. The receiver is sensitive and the ability to choose from four frequencies is a real plus.

73 de KZ4TN

Steve Allen
Elizabethton, TN


Gorgeous work there, Steve! Thank you for sharing!

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Ron reminds us that MFJ still offers a shortwave radio kit

Following up on our recent MFJ post, SWLing Post contributor, Ron, writes:

Another thing about MFJ is they still offer the MFJ-8100 as a kit or built. This is the only regenerative receiver available as far as I know.

Mr. Jue and his guys did a couple of tweaks like limiting band coverage to insure stability, using 1/8 inch 3.5mm stereo phone jacks and use an LM386 audio IC to drive headphones or speaker.

The whole thing is in a metal enclosure to minimize hand capacitance found in most regens.

The QRP crowd likes to use the 8100 with flea power CW rigs, it’s that good.

And it’s been in production far longer than the Heathkit GR-81 or any of the Knight Kit regens, too.

Thank you for sharing that, Ron! I had completely forgotten about this little kit when someone recently asked about the availability of Ten-Tec regen receiver kits (that are, sadly, no longer on the market to my knowledge)! I might have to grab one of these kits–looks like a fun one to build.

Click here to check out the MFJ-8100K.

By the way, I also believe the NM0S Ozark Patrol regen kit is still available from the Four State QRP Group. Click here to check out the product page. It doesn’t have a metal enclosure like the MFJ, but it’s also a fun kit to build.

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Frank recommends the DB4020 QRP transceiver kit by EA3GCY

Many thanks to SWLing Post contributor, Frank (ON6UU), who writes:

As so many, I enjoy reading your posts on the SWLing Post, very clear and understandable written with eye for details. I just did a “read-again” of the QCX+ article and thought that maybe you also would be interested in another European kit, namely the DB4020 by Javier Solans of QRP HAMRADIO KITS in Spain.

The DB4020 is a 2 band kit enabling you to do 40 and 20 meters, SSB and CW. The SSB part of the kit can be obtained for 150€ (169$), Print is a beautiful doubled sided silkscreen with enough space to mount all parts without problems. Some SMD parts are factory installed by Javier, all other parts are normal parts that can be soldered by anyone who knows how to hold a soldering iron. The CW part is an additional module which needs to be plugged into the main board. There will also be a CW filter available soon.

For more information please see : https://www.qrphamradiokits.com/transceivers/db4020-dual-band-ssb/#cc-m-product-12710260049

I’m building the kit at the moment and enjoy every minute of it. I’m not related or don’t have any benefit in sending you this mail, only want to draw some attention to a great kit and super friendly owner who goes the extra mile to have happy customers.

Have a great day

Thank you for the tip, Frank–and I’m glad you enjoy the SWLing Post! EA3GCY’s kit does look very nice indeed. We would love to see your photos once the kit is complete! It looks like a kit I’d certainly love building!

Click here to check out the DB4020 QRP Kit at QRPHamRadioKits.com.

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Neil’s updated QRP Kits page

The Ozark Patrol regenerative receiver kit is only one of NM0S’ many 4SQRP kit designs.

Many thanks to SWLing Post contributor, Neil Goldstein, who writes:

I know a lot of your readers (especially the QRP ones) may be interested in the update I FINALLY made to the radio kit guide. Added, removed, etc. Lots of cool stuff.

http://radiokitguide.com

Thanks for sharing, Neil! What a great curated list of QRP kits!

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Black Cat Systems’ 22 Meter Band Part 15 CW Beacon Kit

Many thanks to SWLing Post contributor, Robert Gulley (AK3Q), who notes that Black Cat Systems has developed a simple 22 meter beacon kit. The price is $20 shipped! A few details:

The kit includes the PCB and components, including a custom programmed microcontroller that will continuously transmit the ID / callsign of your choice, up to 8 characters, at about 13 wpm.

Small size – just 2 7/8 by 1 1/2 inches. Easy to build, just a few components, all through hole, no surface mount.

When ordering you note your callsign/ID to send and it will be pre-programmed.

Black Cat Systems has all kit details including full instructions on their website.

If you like the idea of building a beacon, you must also check out the beacon Dave (AA7EE) built recently–a true work of art!

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National RF 75-NS-3 receiver kit

NationalRF-75-NS_2

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!

75-NS_3

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.

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Neil’s updated radio kit guide

My Ozark Patrol regenerative receiver kit

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!

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