icom 703 backpack antenna
Portable 3 EL 70cm Band YagiWant to share my recent project of 3 el yagi for 70 cm band. It’s very light, portable and great for backpacking and hiking. I like to hike and want to have only necessary equipment with me. I have decent portable equipment for HF which is IC-703+ and set of J-pole antennas. Many HAMs use a small handled VHF/UHF radios but unfortunately the original antenna is very bad and not efficient. It cause bad communication or radio overheating. I decided to make one antenna that I can handle and have with me every time when I hiking or backpacking. The antenna should be: – small or foldable – have a good performance Finally I found a solution and made this antenna. It met all my criteria. I got a ultralight, foldable and portable pocket size antenna with decent performance. Frequency: 436.00 – 445 MHz with SWR 1:1.5 – 1:1:1.5 and 1:1.1 on 440 MHz. Weight : less than 12 oz I used a material that had in my garage, there is nothing special or expensive.
The boom is a simple fishing rod that I bought on eBay for HF projects. The antenna elements made from 1/8″ (3.18 mm) brass rod. You can find them from K&S Engineering store. Simply drill a two holes, one for reflector another for director. The driven element can be just zip tied to the boom. The important step is tuning. At least you have find a position of driver element whenever you get a lowest SWR on central frequency (the antenna can be tuned ether for SSB or FM). Personally I use this particular antenna only for FM, repeaters and satellites. As you can see on photo, I’d attached my cheap chinese radio directly to the boom. Download in high resolution here or in PDF Feel free to ask me if you have questions. REAL-TIME MONITORs Weather Spark Radar 144 MHz Es in NABbq NightsAmazing ContestSummer ProjectWeekend ProjectCandles ContestCitronella MasonCitronella MosquitoCitronella LampsCamping HacksForwardThese mason jar citronella candles are REALLY EASY and they really keep the bugs away!
What a fun and beautiful summer project! Those flames are amazing! The Go-Bag for ARES or Portable Work This is what I use for my ARES and emergency communication drills as well as for portable work (hiking or backpacking). As you can see it’s a simple backpack that you can find in many sport goods store (for example Big 5). I found that this backpack is perfectly meets my requirements. So what is inside? It’s simple set-up that allows me to work on HF and have everything that I need. Of course it also have an other supplies that you will need for emergency situation or hiking. – IC-703+ (10 Watts with antenna tuner). The great transceiver for portable use. High reliability, ability to work with many antennas, easy to use. – 12 V 10A battery. I use a regular 12 V, 10A battery which cost around $15. The better solution would be a Poly-MH batteries. Light weight and high current. – solar panel + charger. Well this is very useful. Can be used for your battery or ether for your cellphone or other equipment.
This is really up to you. The total weight of this set-up about 18 pounds which is not bad at all. I personally prefer have some snacks and small emergency(survival) kit, medicines and water. Performance are good, not great but definitely enough to provide a communication in case of emergency and operate from any places with. Time to set everything up and get ready is very short and it’s about less than 10 minutes. Of course it’s not a perfect set-up and other people would prefer have something else but the main idea was – use everything that you can find in your home (garage), low cost and efficient work. I have done this many times and when you live in California you never know when the earthquake or different disaster will strike this land. You have to be prepared all the time and personal safety is always first. I’m a CERT (Community Emergency Respond Team) member, Police Department & Fire Authorities Volunteer, member of ARES so my responsibilities are expended.
I hope you’ll enjoy it. Update: After a few years of owning the FT-817nd and using alot of other equipment, I revisited this topic: Yaesu FT-817, Elecraft KX3 and other portable HF radios I am looking lately at a transciever for portable operations this summer, and after some reading and thinking I also found a discussion on one of the blogs I follow, where Roger G3XBM posted about the FT817 vs KX3. This is an interesting issue as the Yaesu FT-817 is basically the definition of portable QRP transcievers, and the Elecraft KX3 is one of the hottest ones out there at the moment, offering a very high-performance reciever in a small and medium-priced package due to SDR-based technology, wich is one of my main interests in ham radio. The first issue one might look at is the price point; an assembled Elecraft KX3 + MH3 microphone + KXBC3 charger is US$ 1120, a standard FT-817ND already comes with mic, charger, battery and an antenna for about US$ 600. An external tuner is an option for both for about the same price, but the KX also has the option of an internal tuner.
If you like to mess around with electronics, have some spare time and want to save about US$100 on the KX3, you can get it as a kit and assemble it yourself. Because the two represent different generations of ham radio technology, the performance in the newer KX3 is undeniably better than what you can get with the older 817. Actually, the reciever in the Elecraft KX3 is so good that it ranks among the top ones available today, beating transcievers that cost 2-3-5 times more. It's user interface is richer, with an actually usable display and alot of buttons available for direct control. It is also newer, has the internal tuner option and offers a bit more power (10W instead of 5W). The Yaesu FT-817ND is simpler, it's reciever is just "OKish" (and rather noisy on 2m/70cm bands) and has been plagued with the delicate finals issue. It is a bit heavier (1.2Kg vs 0.7Kg), the display is not useful at all, the S-meter is more of an on/off type and it has much less buttons, being more menu-driven.
Both target the portable operations crowd, where lightweight, simplicity and reliability are the key factors. Therefore, the 817's modest interface becomes a plus, the small screen and the few low-profile buttons are much less likely to be damaged while you carry it in the backpack together with a larger baterry, tools or portable atennna parts; it is almost bulletproof in the field compared to the high-tech fragile KX3 that has connectors sticking out on all sides, fancy buttons and the big frontal LCD. The FT-817's extra weight is there because of the internal rechargeable battery wich the KX3 doesn't have (but you can add), and the SDR DSP-based reciever in the KX3 is most of the time worthless in a situation where you are struggling to be heard. Noisy 2m/70cm reciever you say ? Might be, but the KX3 doesn't cover those bands at all. And if you worry so much about the sensitive finals on the baby Yaesu, you can buy two 817's for the price of one KX3 and keep them both with you in the field, you can even use one as a second reciever wich is much more useful than 100dB 2KHz spaced dynamic range.