Which power supply for Grundig Yacht boy 300? - UK Vintage Radio Repair and Restoration Discussion Forum

radio_spirit · 16th Jul 2017, 5:46 pm

Hi everybody,

I have recently acquired a Grundig Yacht Boy 300 at a local flee market. The unit is working perfectly on batteries, but there was no PSU included.

I would like to buy a suitable PSU for it, but do not know exactly which one it needs. Can anybody help?

It only says '7.5 V' on the device where you put the plug, and there is a round whole with a pin in the center. The exact model number is:

GRUNDIG YACHT BOY 300
Z.NR. 7.50027
(It also says 'BATT. 5x1.5V FTZ NR. U 101'. below).

Thanks in advance for your time,

Tim

HamishBoxer · 16th Jul 2017, 6:52 pm

7.5V sounds a safe bet from a mains PSU.

PS Welcome to our forum,I should have said first.

julie_m · 16th Jul 2017, 7:35 pm

You can get "generic" power supplies with a selectable voltage output and a selection of plug tips to fit various appliances. A transistor radio should not need more than 300mA (but a higher-rated one will not do any harm). Watch the polarity, though. A lot of older kit had the centre pin as negative, although the more common standard today is for the centre pin to be positive. If in doubt, check for continuity between the centre pin of the input socket and each battery terminal.

bobskie · 16th Jul 2017, 7:58 pm

the 300B has a centre negative so its presumably, though not necessarily the case for the 300. This model uses 4.5 volts however. I agree with the suggestion of buying a multi power supply I have one running my dab radio and it has been fine.

simpsons · 17th Jul 2017, 6:49 pm

The schematic, which is available on this site, tells me that the centre pin is positive and requires 7.5 volts. I see that a Sangean DAB Radio 7.5 volt power supply, which has the right polarity plug, costs £9 from a well known source. What I can't tell is if the plug diameter is correct. A little work at your end will solve the question.

Chris nee Simpsons

radio_spirit · 19th Jul 2017, 8:13 am

Thanks heaps guys! I will check it, order a PSU and let you know how it worked out.

SteveCG · 19th Jul 2017, 1:18 pm

... by the way, just check that the PSU provides a Regulated output. That is, on no load (nothing connected to it) the voltage is still 7.5 Volts. There was a range of PSUs sold that provided an unregulated output. For these the 7.5 Volt setting, on a small load like a transistor radio, could well be 12 or more Volts. Such a voltage would damage your radio.

HamishBoxer · 19th Jul 2017, 3:30 pm

Might it be possible to get the correct Grundig supply on Ebay perhaps?

bobskie · 19th Jul 2017, 4:26 pm

Quote:

Originally Posted by SteveCG

... by the way, just check that the PSU provides a Regulated output. That is, on no load (nothing connected to it) the voltage is still 7.5 Volts. There was a range of PSUs sold that provided an unregulated output. For these the 7.5 Volt setting, on a small load like a transistor radio, could well be 12 or more Volts. Such a voltage would damage your radio.

I have noticed this with a couple of AC adapters I own, I didn't know the specifics behind it though.

radio_spirit · 10th Aug 2017, 12:37 pm

Hi, just wanted to report back here.

I bought a multi power supply with positive center pin that has a perfect adapter for the YB300, but it does nothing when attached to it. Maybe it is partly broken and runs only on batteries -- this may even be the reason why they didn't include the power supply on the flea market.

So thanks for all your suggestions, but it looks like I will have to keep running it on batteries. I bought some rechargeable batteries (already have and need tons anyway for flash photography in the studio) and now use it with them.

@HamishBoxer
I already tried getting the correct supply on Ebay, but was not lucky. There were power supplies for many different Grundig models, many for the Yacht Boy 400 for example, but none for the 300 when I checked a few weeks ago.

Edward Huggins · 10th Aug 2017, 6:00 pm

You don't always need to buy expensive batteries. You can run multiples of AA 1.5V batteries (in this case just 5 cells) using an adpator to give you your 7.5 volts.

'LIVEWIRE?' · 10th Aug 2017, 6:30 pm

The type of socket fitted to your Grundig incorporates a Battery/Mains Changeover switch, operated by inserting the DC output plug of your power supply into the socket. The changeover switch could be faulty, and/or possibly have been bypassed so that the radio will only run on batteries.

16th Jul 2017, 5:46 pm	#1
radio_spirit Retired Dormant Member Join Date: Jul 2017 Location: Frankfurt am Main, Germany Posts: 3	Which power supply for Grundig Yacht boy 300? Hi everybody, I have recently acquired a Grundig Yacht Boy 300 at a local flee market. The unit is working perfectly on batteries, but there was no PSU included. I would like to buy a suitable PSU for it, but do not know exactly which one it needs. Can anybody help? It only says '7.5 V' on the device where you put the plug, and there is a round whole with a pin in the center. The exact model number is: GRUNDIG YACHT BOY 300 Z.NR. 7.50027 (It also says 'BATT. 5x1.5V FTZ NR. U 101'. below). Thanks in advance for your time, Tim

16th Jul 2017, 6:52 pm	#2
HamishBoxer Dekatron Join Date: Aug 2007 Location: W.Butterwick, near Doncaster UK. Posts: 8,930	Re: Which power supply for Grundig Yacht boy 300? 7.5V sounds a safe bet from a mains PSU. PS Welcome to our forum,I should have said first. __________________ G8JET BVWS Archivist and Member V.M.A.R.S

16th Jul 2017, 7:35 pm	#3
julie_m Dekatron Join Date: May 2008 Location: Derby, UK. Posts: 7,735	Re: Which power supply for Grundig Yacht boy 300? You can get "generic" power supplies with a selectable voltage output and a selection of plug tips to fit various appliances. A transistor radio should not need more than 300mA (but a higher-rated one will not do any harm). Watch the polarity, though. A lot of older kit had the centre pin as negative, although the more common standard today is for the centre pin to be positive. If in doubt, check for continuity between the centre pin of the input socket and each battery terminal. __________________ If I have seen further than others, it is because I was standing on a pile of failed experiments.

16th Jul 2017, 7:58 pm	#4
bobskie Hexode Join Date: Apr 2017 Location: Falkirk, Stirling, UK. Posts: 336	Re: Which power supply for Grundig Yacht boy 300? the 300B has a centre negative so its presumably, though not necessarily the case for the 300. This model uses 4.5 volts however. I agree with the suggestion of buying a multi power supply I have one running my dab radio and it has been fine.

17th Jul 2017, 6:49 pm	#5
simpsons Octode Join Date: Feb 2007 Location: Harrow, London, UK. Posts: 1,493	Re: Which power supply for Grundig Yacht boy 300? The schematic, which is available on this site, tells me that the centre pin is positive and requires 7.5 volts. I see that a Sangean DAB Radio 7.5 volt power supply, which has the right polarity plug, costs £9 from a well known source. What I can't tell is if the plug diameter is correct. A little work at your end will solve the question. Chris nee Simpsons

19th Jul 2017, 8:13 am	#6
radio_spirit Retired Dormant Member Join Date: Jul 2017 Location: Frankfurt am Main, Germany Posts: 3	Re: Which power supply for Grundig Yacht boy 300? Thanks heaps guys! I will check it, order a PSU and let you know how it worked out.

19th Jul 2017, 1:18 pm	#7
SteveCG Nonode Join Date: Jun 2009 Location: Herefordshire, UK. Posts: 2,495	Re: Which power supply for Grundig Yacht boy 300? ... by the way, just check that the PSU provides a Regulated output. That is, on no load (nothing connected to it) the voltage is still 7.5 Volts. There was a range of PSUs sold that provided an unregulated output. For these the 7.5 Volt setting, on a small load like a transistor radio, could well be 12 or more Volts. Such a voltage would damage your radio.

19th Jul 2017, 3:30 pm	#8
HamishBoxer Dekatron Join Date: Aug 2007 Location: W.Butterwick, near Doncaster UK. Posts: 8,930	Re: Which power supply for Grundig Yacht boy 300? Might it be possible to get the correct Grundig supply on Ebay perhaps? __________________ G8JET BVWS Archivist and Member V.M.A.R.S

10th Aug 2017, 12:37 pm	#10
radio_spirit Retired Dormant Member Join Date: Jul 2017 Location: Frankfurt am Main, Germany Posts: 3	Re: Which power supply for Grundig Yacht boy 300? Hi, just wanted to report back here. I bought a multi power supply with positive center pin that has a perfect adapter for the YB300, but it does nothing when attached to it. Maybe it is partly broken and runs only on batteries -- this may even be the reason why they didn't include the power supply on the flea market. So thanks for all your suggestions, but it looks like I will have to keep running it on batteries. I bought some rechargeable batteries (already have and need tons anyway for flash photography in the studio) and now use it with them. @HamishBoxer I already tried getting the correct supply on Ebay, but was not lucky. There were power supplies for many different Grundig models, many for the Yacht Boy 400 for example, but none for the 300 when I checked a few weeks ago.

10th Aug 2017, 6:00 pm	#11
Edward Huggins Dekatron Join Date: Sep 2015 Location: Southwold, Suffolk, UK. Posts: 8,324	Re: Which power supply for Grundig Yacht boy 300? You don't always need to buy expensive batteries. You can run multiples of AA 1.5V batteries (in this case just 5 cells) using an adpator to give you your 7.5 volts. __________________ Edward.

10th Aug 2017, 6:30 pm	#12
'LIVEWIRE?' Rest in Peace Join Date: Mar 2006 Location: N.W. Oxfordshire(Chipping Norton) Posts: 7,306	Re: Which power supply for Grundig Yacht boy 300? The type of socket fitted to your Grundig incorporates a Battery/Mains Changeover switch, operated by inserting the DC output plug of your power supply into the socket. The changeover switch could be faulty, and/or possibly have been bypassed so that the radio will only run on batteries.