Oceanic Multi Band Receiver
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Location: Kanahooka, NSW
Member since 18 November 2016
Member #: 2012
Postcount: 712
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Hi all, I need a circuit and preferably a service manual for this multi Band reciever. I will send some pictures to Brad and hopefully when he has time they can be added to this thread. It bears no model number anywhere. Not sure why I bought it. It is a tranistor mains battery set. The power transformer has basically an open circuit primary very high resistance. On battery it sometimes works after a delayed start. The speaker was manufactured in Taiwan. It will be quite nasty to remove the chassis without a service manual. It might be better as a door stop.
Regards Jimb.
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Administrator
Location: Naremburn, NSW
Member since 15 November 2005
Member #: 1
Postcount: 7444
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Photos uploaded.
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A valve a day keeps the transistor away...
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Location: Hobart, TAS
Member since 31 July 2016
Member #: 1959
Postcount: 573
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There are a lot of steps of normal diagnostics that would probably get this going OK without having a circuit or service manual.
The mains TX primary winding in this type of unit would normally be a fairly high impedance.
It’s not open as you say if you can measure resistance.
The audio stage on a separate board is fairly obvious, so measurement of the main rail, current it’s drawing and if indeed it’s working should be fairly simple.
Don’t try and pull the chassis out at this stage, as all you will achieve is probably a man made fault (pulled off wires etc).
Get your meter out and have a go.
Then you will have some facts that will explain why it’s not operating.
JJ
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Location: Sydney, NSW
Member since 28 January 2011
Member #: 823
Postcount: 6797
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That strikes me as a badge-engineered radio. Let us know the transistor types and counts thereof in it.
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Location: Wangaratta, VIC
Member since 21 February 2009
Member #: 438
Postcount: 5461
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I don't think I would be messing with the transformer just yet, if it's playing up on batteries. It could be anything from a dry joint, to a dodgy on off switch, to the contact of the batteries themselves; even a dry joint on the board (they're still popular). Some of those slider pots can give trouble
IC clips are good for monitoring voltage.
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Location: Kanahooka, NSW
Member since 18 November 2016
Member #: 2012
Postcount: 712
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Thank you Brad once again for uploading the photos.
Johnny you are quite right I seem to have adopted a defeated attitude towards this. I do not normally do so.
When time permits I will approach it with a more positive attitude. GTC. I think you May be right it would be difficult to know who manufactured it. Thank you Marcc I had already checked out some of these things. However for some reason, I lost some enthusiasm on the way that may have been the result of having stuff that needed to be attended to. So I will now approach it as I should have done in the first place. I will keep you posted.
Regards Jim.
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Location: Hill Top, NSW
Member since 18 September 2015
Member #: 1801
Postcount: 2109
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Looks like the little knob at the top of the FM antenna is missing.
A few days ago someone gave me a National unit similar to this. It has a cassette player, FM, AM, SW.
The radio side works, apart from being totally deaf at the bottom of the SW band.
The cassette looks like it would play, but there's very little torque for FF and REW. Didn't actually try a cassette though.
Some of the controls are a bit noisy and intermittent, such as TONE and the band selector.
I don't really have a use for this unit though.
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Location: Wangaratta, VIC
Member since 21 February 2009
Member #: 438
Postcount: 5461
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There are pressures to distract. I have two engines that need serious attention: But not during bushfire season. I am working my way through the Mens Sheds cables & such. & as mentioned the radio section has around five fixers in the line. The days are really to short at the moment.
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Location: Kanahooka, NSW
Member since 18 November 2016
Member #: 2012
Postcount: 712
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Hello again from Jimb.
Hi Robbbert yes it is missing the tops on both telescopic antenna I am not to worried about that.
Hi Marcc yes like you, I am involved with a couple of charities which take a lump out of a week,however it is not good to spend the week in hibernation in the garage and we all need to keep ourselves occupied doing what is useful and beneficial. I find I sink into depression if I am not occupied.
Well!! Back to this radio I am very grateful for the common sense comments made on this forum. At times I feel a bit of a twitt. Those of you that commented on the power transformer were absolutely correct it is ok. The primary resistance is over 1k ohm for some reason I expected it to be no more than 200 ohms, how wrong was I!
Thank you all that suggested I should not immediately think of removing it from the case. The intermittent I think was caused by the band bank select switch. I gave it a good clean with electronic cleaning solvent and so far it has been working ok. Thank you all very much for your input.
Regards Jimb.
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Location: Sydney, NSW
Member since 28 January 2011
Member #: 823
Postcount: 6797
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Do a count of the transistor types and let us know. There may be a schematic available for it.
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Location: Kanahooka, NSW
Member since 18 November 2016
Member #: 2012
Postcount: 712
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Location: Kanahooka, NSW
Member since 18 November 2016
Member #: 2012
Postcount: 712
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Hello GTC.
Thank you, however not able to see transistor types without twisting and bending them. There are 4 on the audio board. Not sure how many on main board could be 15 however some could be diodes. One of the transistors is 2SB156 others P514 P501 EP1502. It is now working reliably so I don't want to upset it.
Thanks anyway Jimb.
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Location: Sydney, NSW
Member since 28 January 2011
Member #: 823
Postcount: 6797
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not able to see transistor types without twisting and bending them
I use dental mirrors and a good torch for such tasks.
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