Hacker Sovereign radio

[Ariodante]

I'm looking for a mains adaptor for my Hacker Sovereign radio, as PP( batteries no longer seem to be available or reliable.  Apparently I need a regulated output adaptor with a fixed output voltage between 14v and 18v.  Current rating anything over about 200mA.  Ideally it should be a linear type.  Can anyone help please?

I'm reluctant to give up on the Hacker, not just because it's a brilliant radio, but also me and my mother used to work for Hacker in Maidenhead and she got the last Sovereign off the production line when the factory closed.

[ppppenguin]

Hello and welcome to the forum. There are many low voltage adaptors available, but there are a plethora of voltages and connectors which can be very confusing. Most are now switchmode rather than linear. These may work OK but can give unacceptable background noise on the radio. I don't know which connector the Hacker uses but there are several concentric circular connectors that look very similar. Then there's voltage as you mention. There is also polarity. Most adaptors and devices are centre pin positive but I have a nasty suspicion that Hackers are negative centre pin.

Confused? If I were looking for the right adaptor, even with good technical knowledge, I'd still need to be careful.

There is an alternative. You can get battery holders that will take 6x AA cells. These will easily fit in the space occupied by a PP9 battery. This sort of thing, though this doesn't have the correct snap connectors to directly replace a PP9: https://cpc.farnell.com/multicomp-pro/mp...dp/BT06498

PS: I've had a quick look around and found this which is claimed to be suitable for a Hacker Sovereign. It may well be OK but I can't be 100% sure: https://www.amazon.co.uk/Negative-Centre...B07Y8LSNT9

[Ariodante]

Thanks very much for the info ppppenguin.  Just to clarify, if the holder for 6 AA batteries doesn't have correct snap connectors, how would I connect it to the radio?  In the actual picture of the holder, it actually looks like the right connectors are present....

[Refugee]

That battery holder will have a pair of PP3 on it. You will need to make an adapter.

[Ariodante]

Thanks Refugee, but how on earth do I make an adaptor?  I have zero electronics expertise. Is there a person or company that can do this?

BTW, I believe the Hacker mains connector port has got a negative centre pin.

[ppppenguin]

There are PP9 replicas available, using sets of 6x AA cells. An example: https://www.ebay.co.uk/itm/115494897430

So for a zero expertise approach your options are:

1: PP9 replica
2: Mains power adaptor like the one I mentioned in a previous post

[Mark Hennessy]

Or look for the official power supply - the Hacker VP408. They do come up occasionally on places like eBay.

Because you say 14-18V, I'm assuming you have a later RP25A or B, as those came with DC input sockets (this was added at some point during the life of the "A" model). But sometimes DC input sockets were retro-fitted by dealers, either using a kit supplied by Hacker, or not, if they came up with their own solution.

You're right to be wary of switched-mode supplies as these models are extremely fussy about power supply noise. Even the VP408 causes a little bit of background hum, despite having less than 5mV ripple. Sadly, linear power supplies are very rare today, but with a bit of patience you might find something suitable second-hand for not much money. As has been said, be extremely careful about the polarity as most are wrong for this radio, and the radio has no protection at all. If you haven't already got one, it's worth picking up a cheap multimeter so you can check this before connecting a power supply to the radio. Changing the polarity of a power supply is easy with just a "choc block" terminal or similar - might not be pretty, but no soldering needed.