[EdHolland]

This British beauty is the latest to join my collection of communications receivers (which has got rather out of hand...). Pics to follow.

The Lowe Electronics range was a home designed and produced collection of receivers built to high standards. Although appearing less glamorous than the Kenwood, Yaesu, Icom and JRC sets, they give away nothing in performance or user convenience. Since their launch in the 1980s, I've been an enthusiastic fan of these radios, which were produced not far from where I grew up. 

The HF 235 was launched as a premium, ruggedised version of the HF-225, aimed at professional and military users and offered for sale in the very late 80's and early 90's. It was proudly claimed that the BBC acquired them for monitoring work. I was delighted to find evidence supporting this (A BBC sticker) on the very set that is now on my radio bench.

Modern radio by our Phorum's usual standards, but even 30 year old equipment might need a helping hand here or there, and so it was with this example. Fortunately, I'm familiar with the way these radios are designed, and have all the service info.

On first applying power, there were no major problems, but certainly a couple of items for attention:

• The rack mounting flanges were a little distorted, as described by the seller. Careful dismantling of the case and straightening was successful
  
• The IF gain control was scratchy and intermittent. It responded to a very sparing squirt of cleaner, and some long overdue exercise.
  
• Tuning was a little off, when checked against WWV, and there was a slight tracking error. A few hundred Hz, spec by the book is +/-50 Hz
  

On the tuning calibbration there are three adjustments called out in the alignment procedure. First is the master oscillator, from which all the local oscillator frequencies are derived. Adjustment is easy, but I had a worrying moment - as the trimmer freed up, the oscillator made a wild jump in frequency, and was extremely jumpy when attempting adjustment. This must have been a dirty wiper contact inside the trimmer as it eventually settled back close to the initial frequency value. It was then adjusted so that the same offset was present when tuning to WWV on 5, 10 and 15 MHz. This ensured that the scaling error was corrected.
The design is double conversion to a 45 MHz IF, then to 455 kHz for audio bandwidth filtering. The first local oscillator is tuned in 1 kHz steps, and the second conversion oscillator is adjusted in 8Hz steps to provide smooth tuning. Each time the first conversion makes a 1 kHz jump, the second conversion must go from one end to the other of its range. If the range is wrong, this is heard in the tuning as a discontinuous jump in frequency. A preset pot is provided to adjust the range, and this was easily set to restore constant change in tuning as the control is operated. Finally, the second oscillator has a trimmer to allow correction of offset in frequency. With these adjustments performed and double checked, the set was operating within specification on all frequencies.