Hendricks QRP radio - an easy intro to kit building

The holy grail of ham radio is to build your own equipment - receiver, transmitter, antenna - the works. So when my grandson needed a radio project for Cub Scouts I persuaded him that building a shortwave receiver was exactly what he needed to impress his follow scouts, and get me on the road to creating a home-built rig.

I searched the web and compared prices, features, and ease of building and selected the Scout Regenerative receiver from Hendricks QRP Kits. The kit features two bands (3.5 mHz to 10 mHz) powered by a 9-volt battery or optional 12-volt external power source.

The kit includes a double-sided silk-screened printed circuit board and all components, and very clear step-by-step instructions, including tests to insure everything is working as you complete the kit. The instructions recommend identifying all of the parts before starting, but this was fast and easy thanks again to the color photos included by Hendricks. Only basic tools are needed for construction - a 30 watt soldering iron, 60/40 rosin core solder, and a multi-meter. The printed circuit board is double-sided, so soldering is straightforward. As with any electronic kit construction, paying close attention to putting the right part in the right plus being careful about polarity for electrolytic capacitors and diodes is critical. Removing soldered parts is a hassle, so I was lucky that everything went in correctly the first time.

Hendricks provides convenient construction check points to test voltage and current through the circuit. My measurements were close but not exactly on the mark as indicated in the manual.

Perhaps the hardest part of construction was winding the coils. It requires at least three hands to hold the wire tight, insert it through the holes in the PVC pipe, and tie it off so it doesn't unravel. When winding coils, neatness counts. Too many - or too few - turns in the coil push the tuning out of tolerance, so count carefully.

With the last component soldered in place, I did a quick review of the plans, snapped in the 9-volt battery, attached a long wire antenna, and plugged in a pair of earphones. WoW! China Radio International, Radio Havanna, Radio Tirana - I could hear them all. True, the regeneration control takes some getting used to, sort of like letting out the clutch while stepping on the gas in a manual transmission, but once you get used to it it becomes second nature.

All in all, Hendricks has done a nice job of creating a sensitive regen shortwave receiver for $40. And yes, my grandson's Scout buddies were impressed!

- 73

- Steve KB3IHX

Scanning the airwaves

I’m an avid Police/Fire scanner enthusiast. When the sirens sound, I reach for my scanner. I’ve heard everything from criminals stealing police cars to cops chasing bank robbers on foot. If it’s happening, I want to know about it. So when I went on vacation this summer I took my scanner with me.

I have two scanners – a RadioShack Pro-97 and an ICOM IC-R5. Both are programmable via serial cable and offer a thousand or more memory channels, but that’s where the similarity ends. The PRO-97 scans both trunked and conventional frequencies, but scans only within specific bands (25-54 MHz, 108-136.9875 MHz, 137-174 MHz, 216.0025-221.9975 MHz, 222-225 MHz, 225.025-405.975 MHz, 406-512 MHz, 806-960 MHz excluding cellular frequencies, and 1240-1300 MHz), all using AM / FM modes. The IC-RX5, on the other hand, is a wide band receiver (495 kHz – 1309 MHz with cellular frequencies blocked), and AM / FM / WFM modes are selectable.

Neither scanner is particularly user-friendly, something that seems to be a common characteristic of scanners. The only reasonable option is to clone frequencies using a PC and a cable. Fortunately both scanners have good PC-based software alternatives.
For the Pro-97, Win97 (www.starrsoft.com/) offers the best mix of features and ease of use. The GUI is clearly labeled and allows copy-and-paste from one section to another, and from spread sheets. Even better, Win97 lets you download and import frequencies from RadioReference.com. Note that this requires a premium membership from RadioReference. Win97 is stable, even on Vista.

An added benefit of the Pro-97 is the PowerScan feature that picks up any strong signal within 1000 yards. Don’t know the exact frequency, but you’re close to the action? Hit PowerScan and you’re in business.

The ICOM requires either the OPC-474 cloning cable (radio-to-radio) or the OPC-478U with Windows cloning software. The ICOM software is functional, if unimaginative. ICOM does offer a very clumsy download feature from their site that lets you select stations based on various criteria – none useful – for import into their software. You’ll need a stiff drink before tackling this one, though.

So, you want to know the real scoop on why your plane is delayed? Use your scanner – discretely, of course – to listen in on air traffic control. My snooping once revealed that the company had misplaced the plane. Misplaced! They had a crew, but no plane! This gives a whole new meaning to “lost luggage.”

Nevertheless, which ever scanner you use, if you have a taste for vicarious violence, unfortunate occurrences, or virtually anything else that involves radio communications, don’t forget to pack your scanner before leaving home.

- 73
- Steve KB3IHX