Tag: kits & homebrew

EC-012 – Analog Electronics

I signed up for this online course offered by ARRL which starts Friday to try and improve my understanding of basic electronics. Here’s the course description.

This course is designed for the electronics beginner that has an interest in electronics and has been introduced to the fundamental concepts of electricity and electronic components, such as resistors, capacitors, transistors, and so forth. You’ll be reading some simple schematics, as well. In 16 learning units and about 25 hours the student will learn about the use of instrumentation, Kirchhoff’s Laws, Diodes, Rectifier circuits, Bipolar and Field Effect Transistors, various amplifier configurations, filters, timers, Op-Amps, and voltage regulators. Most lessons have design problems and optional construction projects. This course will run for a 12-week period, and earns 2.0 CEUs.

I’ve already purchased most of the electronic components for the class. I want to try and put together a mobile workshop that will allow me to keep all my building equipment in one spot and allow me to work in different rooms of the house.

This weekend in the shack…..

GYFWW: Get Your Feet Wet Weekend. This was an interesting event… all CW. My CW skills are atrocious and this was my attempt at improving. I enjoyed it, although at times it was very frustrating. The exchange was RST, name, state, FISTS #, and year licensed. Most folks were good at slowing down and repeating missed parts of the exchange. I spent a lot of time just sending CQ without a response. A contest doesn’t have the personal interaction of a regular QSO. At the end of the contest I had 18 contacts and over 200 points… no records broken here. I still have a long way to go on the CW. I would like to get my speed up to 15-20wpm – that will take a lot of consistent work.

Virginia Beach Hamfest: My second year attending the Virginia Beach Hamfest. A two-day hamfest, I went on Sunday. $5 to get in. There were a few vendors, but I had primarily come this year for RadioWorks, a local company from Portsmouth that makes great wire antennas. I purchased a Carolina Windom, 133′ long, good on 80M to 10M. The challenge now is to hang that bad boy. I’ll be assisted by my CSV19 Pneumatic Antenna Launcher.

T-238+ APRS WX Project: The main board was good to go. I put the modem board together Friday night, checked out and good to go. Then came Saturday, I was interfacing the WX sensors (temp, wind speed and direction)… it worked! I was getting the data to read out properly. However, when I tried to interface the modem board with the radio, the LCD screen started showing all solid squares instead of text and the heat sink got very, very hot. The LED heartbeat light is still functioning, but clearly there is something wrong. Hope I’m not back to square one. http://www.tapr.org/kits_t238plus.html

QST Articles: SB-220 Heathkit HF Linear Amplifier

1970 August QST p. 45 Heath SB-220 Linear Amplifier (Recent Equipment)

1974 December QST p. 47 SB-220 on 6 Meters (H&K)

1978 November QST p. 40 Heath SB-220 Modifications

1979 February QST p. 20 Upgrading Your Heath SB-220 Linear Amplifier (Feedback: Apr. p. 27; Jul. p. 50; Nov. p. 56)

1980 January QST p. 25 All Solid-State QSK for the Heath SB-220 (Feedback, Feb. p. 44)

1988 January QST p. 45 Using the SB-220 Amplifier with Solid State Transceivers (H&K)

1988 September QST p. 45 No Holes Standby Switch Modification for the Heath SB-220/SB-221 Amplifier (H&K)

1989 February QST p. 42 Improving the Heathkit SB-220 Amplifier

1989 November QST p. 25 Circuit Improvements for the Heath SB-220 Amplifier–Part 1

1989 December QST p. 41 Circuit Improvements for the Heath SB-220 Amplifier–Part 2

Field Day Wrap Up

I had a good time. Putting together the Amateur Radio Station In a Box (ARSIB) was a good learning experience. I now have a functional, portable system that I can take anywhere to operate. The actual operation and contacts during field day was very enjoyable. Other than the lighthouse activations and the W4M special event station for Memorial Day, I don’t do a lot of phone. So all the phone contacts were good experience. No big DX and no new states (still missing Alaska, Hawaii, and Wyoming for WAS).

I wish I had tried setting up my homebrew vertical dipole to see how it did against my end fed inverted vee.

I’d also like to get one of the Heil Traveler headphone/boom mike devices that has a PTT switch. I think it would make operating easier having a boom mike than constantly picking up and setting down a hand mike. I’d also like to try to integrate some type of control software between the radio, the laptop, and the logging program. I’m going to give FT-817 Commander a try. I know there are similar applications for my IC-706MKIIG,

I need to take advantage of some of the easy way to get more points….:
– Message Origination to Section Manager: 100 bonus points for origination of a National Traffic System (NTS) style formal message to the ARRL Section Manager or Section Emergency Coordinator.
– Satellite QSO: 100 bonus points for successfully completing at least one QSO via an amateur radio satellite during the Field Day period.
– W1AW Bulletin: 100 bonus points for copying the special Field Day bulletin transmitted by W1AW.

For next year I would like to try and operate away from the house. Maybe combine it with a summer vacation trip.

A Simple ‘Iambic Paddle’ for Travelers


From : Charles & Sandra Cohen

Scott —

Sorry, no parts list. And the bottom is covered by silicone rubber, so a photo won’t help you.

Radio Shack should have everything except maybe the two switches. Those, you could get at any electronic parts distributor as “tactile switches”. They come in various sizes. Mine are 12mm square, with a 160 gm activation force. (less activation force would be better, but I wouldn’t want anything smaller).

The top of my phone jack was transparent, and I could figure out which pin (on the bottom) corresponded to which phone plug contact. You might have to enlarge one or two holes in the board, and I bent or broke one unused pin. But the rest of the pins go through the holes to the back of the board, and hold the phone jack in place.

Each switch has four pins (two for each side of the switch contacts). I just pushed them through the holes in the board without any sockets. The pins fit tightly enough so there’s no play after the pins are soldered (as described next).

On the back of the board, there are four wires soldered in place:

One from the “dit” switch to the “tip” contact of the phone jack;

One from the “dah” switch to the “middle ring” contact of the phone jack;

One from the “ground” (outer barrel) contact of the phone jack to the _other side_ of the “dit” switch;

Another from the “ground” contact of the phone jack to the _other side_ of the “dah” switch.

The ceramic fridge magnets (Krazy-glued to the back) are thick enough so that the pins of the switches and phone jack don’t touch the FT-817. I covered the soldered joints with silicone sealant — no possibility for accidental shorts, that way.

That’s it. This was one of the few times that something I built worked right on the first try. This is _not_ a fancy project.

Good luck !

Charles

Homebrew vertical dipole

I’ve been looking around for good ideas for a portable HF antenna and finally settled on Robert Johns’ (W3JIP) plan from a QST article (Aug 88). The antenna design is a vertical dipole (6M to 40M), using a loading coil at the base of the vertical with a tap and the other half the dipole is formed with a 1/2 wave length cut of wire. The coil is mounted on a 3/4″ PVC pipe which slips into a 6″ length of aluminum tubing. The tubing then slides into a bracket designed to hold a flag. Mounted on the bracket is a SO-239 with the center pin making contact with the bracket. The main element sitting on top of the coil is 8′, but you can lengthen it to 11′.

I spent the morning gathering the parts, had a hard time with some of the specific items, but ended up with a couple work-arounds. I put the coil together first, that went pretty easy. W3JIP’s plan calls for #8 aluminum ground wire for the coil – which no one has. I used copper instead. I wrapped the copper around a 4″ piece of PVC. The directions call for 12 turns, but I only purchased 12′ of copper (the directions didn’t say what length to get)… ended up getting 9 turns. I mounted the coil to the PVC and then secured the trailing end up the coil to a piece of aluminum tubing inserted inside the PVC. The element gets mounted above the coil and I secure the tap at the base of the element.

Once I had everything together, I went outside and mounted the coil section to the top of a tripod, inserted the 8′ aluminum element above the coil, set the tap at the top of the coil, ran a length of wire out as the other half of the dipole, ran some RG-58 out from my Icom 706 and after playing with the tap a bit was able to get out to Texas on 20M.

I have some more work to do:
– better secure the SO-239’s center pin to the bracket and bottom of the coil
– attach a banana plug to the ground side of the SO-239 to allow quick changes for switching bands
– find a way to secure the base of the antenna to a painter’s pole

I know the antenna will work on 20M, now I would just like to get it working on 40M.

Problems with Phase 3

I finsished phase 3 but when it came time to test the xmit mixer and 7MHz filter circuit, I did not get the proper results. After double checking, triple checking my work and looking for any other problems, I called Ten-Tec and talked to Gary. After I explained my problem, the first thing he said was to check the capacitor in C70, that it was suppose to be a 47pF capacitor as opposed to the 470pF that is called for in the instructions. He also mentioned if I had listened for the 11MHz crystal oscillator, which wasn’t mentioned in the instructions and I hadn’t done. So – I replaced the capacitor without too much trouble. Tested everything again and still no luck.

Ham Radio Kits

I’m trying to build up my kit building skills and started with this Vectronics Comprehensive Soldering Course:

This professional-grade soldering course was designed for schools and individuals. Includes theory, quizzes, PC board and components for soldering practice. Taking this course will result in professional soldering skills and fun blinking LED project. This course covers all of the latest tools, techniques and materials you’ll need for “through-hole” style PC board assembly and repair.

When you complete this course you’ll be ready to tackle a wide range of jobs on the bench and in the field. Short, concise lessons cover topics like solders and fluxes, product safety, soldering irons, circuit boars, and much more.

Skill Level: Simple – Calls for a few basic tools — a soldering iron, cutters, pliers, wire-strippers and a small screwdriver.

Note: This is merely the kit. If you would like to purchase a case for your electronic kit as well, you will need to purchase it separately.

…. it took me about three hours to put it together and now I feel a lot more confident with the soldering iron. I attached the battery and the lights started blinking, always a good sign. 🙂

My next kit attempt will be Ten Tec’s 40M QRP CW transceiver kit:
Ten-Tec began in 1968 with the release of very inexpensive “QRP” transceiver kits. We thought it would be fun to revisit those roots. We explored today’s RF technology and components to see just how inexpensive, compact, and simple a quality QRP kit rig could be. The low price and great receiver design make these QSK VFO-controlled transceivers a great choice. Get on the air from anywhere!

The model 1340 40 meter QRP transceiver was reviewed by ARRL in the September 1998 issue of QST.

Good site here for assembly tips: http://www.io.com/~n5fc/tt1340.html

This kit will be much more complicated and take a lot longer. I’m going to take it slow – wish me luck.

New Elecraft Product

80/30m Module for Popular KX1 Portable Transceiver

from Wayne Burdick, N6KR

We’re pleased to announce that the KX1 is now a 4-band radio!

Many KX1 owners have asked for 80 meter coverage, notably Bruce Prior, N7RR, who pointed out that 80 meters is a great band for traffic handling at night (in both the CW and SSB segments). Up till now, Bruce has been taking his KX1 and a second rig that covers 80 meters on his extensive backpacking trips. Our new KXB3080 option will lighten his load a bit. 80 meters is also a popular field day and QRP band, and is especially active in the Eastern U.S. and in Europe. Band noise is lower in Winter, so this is the perfect time to give 80 meters a try.

The dual-band KXB3080 module installs in the same location as our 30-meter-only module, the KXB30. The KXB3080 is very easy to add to your KX1, since all but two components are surface-mount, pre-installed at the factory. (This was necessary in order to provide both bands in such a small amount of space.) Also supplied is a small PC board that mounts in place of the original low-pass filter inductors (L1 and L2). This board includes a relay that configures the low-pass filter for efficient operation on either 80 or 40/30/20 meters.

The KX1’s firmware has been updated in conjunction with the KXB3080. The new firmware adds:

* Full 80-meter band coverage on transmit and receive
* Additional receive-only coverage: 1000 kHz to 5000 kHz (reduced sensitivity outside the 80-m band)
* Programmable scanning (great for monitoring quiet bands, waiting for signals to show up)
* Variable-rate fast tuning: 1 kHz in ham bands in all RX modes, 5 kHz outside ham bands in USB/LSB modes

We have several beta testers lined up for the KXB3080, and will be supplying them kits in a couple of weeks. Meanwhile, I’ve been having great fun on 80 meters with the first 4-band KX1, even with a wimpy 40-foot random wire. In addition to 80 meter transceive operation, I can copy many AM stations from 1.0-1.6 MHz. This broadcast band coverage should prove useful feature for field operation.

If you have any technical questions about the KXB3080 option, feel free to send them to n6kr@elecraft.com. One question I’m sure to get is whether the KXAT1 ATU is usable on 80 meters. The answer? Yes, but the KXAT1 wasn’t designed to cover this band, so it will only help with specific end-fed wire antenna lengths to be determined. It will of course help with tweaking of nearly-resonant antennas, such as portable whips and ad-hoc dipoles.

* * * N O T E * * *

Please don’t call about the KXB3080 or new firmware just yet. We will announce the price of both in late January, and take orders then.

Elecraft Web Site