Hacker Hunter external power - UK Vintage Radio Repair and Restoration Discussion Forum

brendanxx · 29th Dec 2018, 12:35 pm

Hi,
I have a Hacker Hunter that was a 21st present 49 years ago. Tired of buying batteries and want an external power source. I see on Amazon there's offered by GOOD LEAD "18V Mains AC Adapter Power Supply for Vintage Hacker Hunter RP38A Transistor Radio" for £12.49, but when asked specifically if their plug would fit into the Hunter's recessed socket they seemed a little vague.
AC Adaptors r us also offer a "18V Mains AC Adaptor Power Supply for Vintage Hacker Hunter RP38A Transistor Radio" for £14.99 and say they'll sort out any problem if the plug doesn't fit.
Can anyone give me any advice as I certainly don't want to damage the radio or to pay for something that won't fit.
Another question - any idea where I can get a workshop manual for the Hunter?
I must say listening to the Hunter again has given me a real interest in these old radios - a gorgeous balanced, rich, sound. I may even delve into getting one of those lovely old valve sets.
cheers
Brendan

Mike. Watterson · 29th Dec 2018, 1:05 pm

You actually don't need 18V. 16V is fine. Because batteries are only 9V when fresh. End point is about 5.4V to 6.6V, depending on radio design. Hence running off 12V to 14V is possible. Maximum volume is poorer below 15V.
If you can solder you can buy a plug and put it on a suitable adaptor. Ensure polarity is correct. A lighter SMPSU may create LW & MW interference.

mhennessy · 29th Dec 2018, 2:32 pm

I assume that you are talking about this one: https://www.amazon.co.uk/GOOD-LEAD-A.../dp/B01MDU0OIB (a link would have helped - just copy and paste).

If so, do not buy it!

First, look at the label that surrounds your DC input socket. Then, take a close look at the picture on the Amazon web page. Spot anything wrong?

Mike's advice about voltage might be reasonable in very general terms, but there are exceptions and this particular set is one. If like me you live in a poor VHF reception area, then battery voltage is especially important for the Hunter. If you're buying an adaptor, you might as well get the right voltage - a 16V adaptor is no easier to find or cheaper than an 18V unit. That's if you can find one that works at all.

Unfortunately, this is a switched-mode unit. It will generate too much RFI for this radio to work correctly. And because they no longer manufacture AC adaptors based around traditional 50Hz mains transformers, all similar units will have the same problem.

Keep an eye out for the Hacker VP408. This is the correct unit designed by Hacker for their sets. Failing that, trawl the car-boot sales looking for a traditional DC power supply of the correct voltage. You might need to replace the DC plug, but as you're asking for the service manual, then presumably that is an easy task for you?

Nuvistor · 29th Dec 2018, 3:45 pm

There is a RP38 manual in the service manual search at the top of the page, the RP38A is slightly different and I have forgotten just what that is.
I think I found the RP38A manual in the Hacker Radio Yahoo groups. Possibly put there by Mark.

If you can find a VP408 get it, it’s a linear PSU and is designed for various Hacker radios with a variable voltage output. It works well with my RP38A.

29th Dec 2018, 12:35 pm	#1
brendanxx Retired Dormant Member Join Date: Dec 2018 Location: Hastings, East Sussex, UK. Posts: 1	Hacker Hunter external power Hi, I have a Hacker Hunter that was a 21st present 49 years ago. Tired of buying batteries and want an external power source. I see on Amazon there's offered by GOOD LEAD "18V Mains AC Adapter Power Supply for Vintage Hacker Hunter RP38A Transistor Radio" for £12.49, but when asked specifically if their plug would fit into the Hunter's recessed socket they seemed a little vague. AC Adaptors r us also offer a "18V Mains AC Adaptor Power Supply for Vintage Hacker Hunter RP38A Transistor Radio" for £14.99 and say they'll sort out any problem if the plug doesn't fit. Can anyone give me any advice as I certainly don't want to damage the radio or to pay for something that won't fit. Another question - any idea where I can get a workshop manual for the Hunter? I must say listening to the Hunter again has given me a real interest in these old radios - a gorgeous balanced, rich, sound. I may even delve into getting one of those lovely old valve sets. cheers Brendan

29th Dec 2018, 1:05 pm	#2
Mike. Watterson Heptode Join Date: Dec 2014 Location: Limerick, Ireland. Posts: 901	Re: Hacker Hunter external power You actually don't need 18V. 16V is fine. Because batteries are only 9V when fresh. End point is about 5.4V to 6.6V, depending on radio design. Hence running off 12V to 14V is possible. Maximum volume is poorer below 15V. If you can solder you can buy a plug and put it on a suitable adaptor. Ensure polarity is correct. A lighter SMPSU may create LW & MW interference.

29th Dec 2018, 2:32 pm	#3
mhennessy Dekatron Join Date: Jul 2007 Location: Evesham, Worcestershire, UK. Posts: 4,244	Re: Hacker Hunter external power I assume that you are talking about this one: https://www.amazon.co.uk/GOOD-LEAD-A.../dp/B01MDU0OIB (a link would have helped - just copy and paste). If so, do not buy it! First, look at the label that surrounds your DC input socket. Then, take a close look at the picture on the Amazon web page. Spot anything wrong? Mike's advice about voltage might be reasonable in very general terms, but there are exceptions and this particular set is one. If like me you live in a poor VHF reception area, then battery voltage is especially important for the Hunter. If you're buying an adaptor, you might as well get the right voltage - a 16V adaptor is no easier to find or cheaper than an 18V unit. That's if you can find one that works at all. Unfortunately, this is a switched-mode unit. It will generate too much RFI for this radio to work correctly. And because they no longer manufacture AC adaptors based around traditional 50Hz mains transformers, all similar units will have the same problem. Keep an eye out for the Hacker VP408. This is the correct unit designed by Hacker for their sets. Failing that, trawl the car-boot sales looking for a traditional DC power supply of the correct voltage. You might need to replace the DC plug, but as you're asking for the service manual, then presumably that is an easy task for you?

29th Dec 2018, 3:45 pm	#4
Nuvistor Dekatron Join Date: Aug 2013 Location: Wigan, Greater Manchester, UK. Posts: 9,433	Re: Hacker Hunter external power There is a RP38 manual in the service manual search at the top of the page, the RP38A is slightly different and I have forgotten just what that is. I think I found the RP38A manual in the Hacker Radio Yahoo groups. Possibly put there by Mark. If you can find a VP408 get it, it’s a linear PSU and is designed for various Hacker radios with a variable voltage output. It works well with my RP38A. __________________ Frank