In praise of Hacker radios.

[Geordie McBoyne]

Today I learnt that Classic FM were going to play the Borodin second symphony so I decided to give my Hacker Silver Knight an airing. Absolutely brilliant both the musical composition and the radio that was reproducing it. Things got even better because it was followed by Ravel's piano concerto in G.

The Silver Knight is a version of the RP74 Black Knight but with the addition of a stereo decoder.

Geordie McBoyne.

[Mark Hennessy]

I have a small collection of Hacker radios, including a couple of those.

The main problem with that series is the screen printing on the top plate. While I have a fair few that are perfect, some are not. I almost wonder if the surviving good ones came from a different contractor.

In terms of sound quality, the Peerless loudspeaker is the main factor. That unit does have a more extended HF than some of the earlier units, but there is a nasty peak somewhere in the upper midrange/lower treble that the treble control can't remove without killing the HF as well. I plan to measure a good number of samples and see if a notch filter could be added (sympathetically and reversibly, of course).

Another factor is the bass end varies enormously from sample to sample. I did start measuring them about 5 years back, but life got too busy so I had to put that on hold. The surround is treated, so that could be a factor. Either way, some sets have a lovely, warm bass end, whereas others are totally anaemic and sound like a set that is half the size. In all cases that I have encountered, it's not been an amplifier fault, but of course, that's always a possibility to consider before blaming the loudspeaker. Generally, the Sovereign III "family" use those blue Philips capacitors that are highly reliable.

Also, that loudspeaker seems to suffer from cone "sag". Luckily, it's usually easy to fix - you need a block of wood, a hammer, and a fair bit of luck! So far, so good

One to watch for: the stereo decoder is only powered when a DIN plug is inserted. Apart from in one of mine, where a fault allows power through all the time, and that's bad news if you're running on batteries as the decoder doubles the quiescent current!

Personally, the Hunter RP38A edges ahead in sound quality terms. That Elac loudspeaker is very good indeed, and is reliable and consistent from sample to sample IME. But the Hunter has a big problem for me - on VHF, it is less sensitive than the other VHF sets. Plus, that sensitivity is highly variable from sample to sample. Over the years, I've spent a lot of time trying to work out why (I must have repaired at least 50 of them in recent years), and there are no firm conclusions - but the Lockfit BF194/5 transistors are often the (or part of the) problem. But the same transistors are more reliable in other sets, suggesting that something about the Hunter's design is a bit marginal.

Overall, the VHF Herald when fitted with the Elac loudspeaker with the giant ceramic magnet is my favourite. That particular loudspeaker won't physically fit in any other set, but it's an absolute joy in the Herald.

But all that said, any of the "proper" VHF-capable sets are lovely things to listen to. And - importantly - work on. The earlier service manuals are as good as the sets themselves.