Monday, October 05, 2009

New arrival from China

A knock on the door this afternoon heralded the arrival of my latest QRP radio - an HB-1A 3-band (40/30/20m) CW transceiver from China.

Shipment had taken just over a week and, unlike products ordered from the USA, there was no customs charge or VAT to pay, so the radio cost me a total of £165.

Opening the box revealed the radio extremely well packed in expanded polystyrene, plus a photo-printed card with a picture of BG2FX in his lab - presumably the builder. There was no manual, but the eBay listing had linked to an English language manual in PDF form that I could print out.

The radio itself seems very well made, the impression of solidity created by the heavy steel case which is well-painted in a black crackle finish. As this is intended to be a portable radio, an aluminium case would have saved a bit of weight.

Unscrewing two screws and removing the bottom of the case revealed a bit of a surprise - the two 4 x AA cell battery holders were not connected together or to the plug that connects them to the circuit board. I will have to solder together and insulate the wires myself. Four rubber stick-on feet were also inside the case, which I fitted to the bottom of the case before reattaching it.

Applying 12V DC from my shack power supply I was pleased to find that the HB-1A worked perfectly. There is no loudspeaker, output is headphones only, and best results were obtained using a pair of MP3 player style ear buds. The receiver is no match for a K2, but it is quite lively. Selectivity is reasonable and adjustable in three steps - 900Hz, 700Hz and 400Hz for CW - but stopband performance is quite poor: I could hear strong CW signals a few kHz away.

Although this is a CW-only transceiver it can receive LSB and USB as well. Tuning is continuous from below 40m to above 20m so you can even receive shortwave broadcasters by zero-beating the carrier. There is no bandswitch, but the HB-1A has 20 programmable memories which are pre-loaded with useful frequencies in each band such as the QRP CW frequencies - and the broadcast frequencies of Radio China!

The front panel key jack can accept either a straight key or a paddle. This is detected at power-on. However, for a straight key to be detected the center contact of the stereo jack must be grounded. Other radios I have go into continuous key-down unless this contact is open-circuited. Why can't there be a standard?

I was pleased to see that I got a genuine 5W output for 12V DC input. At 9V DC I measured 3W output. I haven't tried batteries yet as I have not yet wired up the internal battery holders.

The battery holders are a tight fit between components on the circuit board and there is no facility for charging rechargeable cells whilst they are installed. I will find removing the bottom of the case, removing the batteries to recharge them and then reinstalling them a bit of a nuisance, so I will be looking to install a socket so that they can be charged in situ.

Despite calling CQ on both 20m and 40m I haven't managed to have any contacts yet - I guess conditions aren't all that good right now.

With a power consumption less than half that of the FT-817 the HB-1A should give decent battery endurance on a set of rechargeable NiMH cells. This is going to be used as a portable HF rig, so the search is on for a small and equally robust Morse key for it. I'm trying to think how I can adapt the DinKey - which turned out to be such a disappointment when used with the FT-817 - so it can be plugged in to the 3.5mm key socket of the HB-1A.

That's all I have to say about this little Chinese radio for now, but I'm sure you'll be hearing more about it once I get everything set up for operation in the field - assuming that the weather plays ball!
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