Today was QRP extreme day. Martyn ZL3CK, Harry ZL1BK, Maurice ZL1MPU and Dave ZL1DL trialed a couple of Martyn’s green radios to check the range. First up was the BC-611; generally recognised as the original “Handie Talkie” even though it weighs in at around in at around 2kg! The BC-611 sports 5 vacuum tubes that are very cleverly reconfigured between receive and transmit by a complicated multipole PTT switch. It represents one of those quantum leaps in technology and even with its shoulder taxing weight, was a massive advance on other “portable” [ almost a misuse of the word ] radios of the time.
The BC-611 delivers a healthy 20mW of RF on a single channel. Martyn’s unit has crystals for 3.885 MHz ( an original channel ) fitted – how convenient! With a relatively short telescopic antenna, this wasn’t going to add up to eyewatering DX. With that in mind, Martyn marched off with lightweight radio in hand. As there was only one BC-611 available, Harry had the tough job of operating “modern” from the luxury of his vehicle parked at the front of the clubrooms.
First up, the TX audio quality from the BC-611 was astoundingly good – none of the narrow band nasal intonation here – this was quality AM! How far does it go? Well probably further than we achieved today; Martyn got at least 20m past the chain at the end of the driveway at which point RX issues on the BC-611 made it difficult. The TX was still booming it at that range. There appears to be some unwanted oscillation occurring on RX, so today’s record may be exceeded in the future.
The next candidate for testing was a #38 set on 40m. Not quite as portable as the BC-611 and with an expected longer range, Martyn installed it in his vehicle and drove off down past the golf course. With a 10ft whip out the window, he reached the end of the drive and still had comms back to the clubrooms. Admittedly, there was an advantage at the clubroom end; running the T98 at 10’s of watts into an elevated 40m dipole. Well, maybe not really a dipole. More of a radiating feedline with a tophat – one side of the feedline has become detached at the dipole feedpoint, so we’ve got work to do on the next fine club day.
Still, the coffee was good!