Marconi Challenger - Ships Nostalgia
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Marconi Challenger

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  #1  
Old 1st August 2019, 20:51
Michael Oceanspan Michael Oceanspan is offline
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Marconi Challenger

I'll admit straight away that I am not an ex mariner, but I do look after the Marine Radio Collection at Internal Fire- Museum of Power in West Wales. I would be very interested to hear from anyone who has any knowledge or experience or perhaps sailed with the Marconi Challenger. There won't be many as, to my knowledge, Marconi only sold about 12 units fro and 18 - 20 production run.
Its a 1.5KW SSB/CW/MCW transmitter, probably technically the best Marconi made, but a marketing disaster! (too much, too late!) The Challenger we have together with the console came from the "Pride of Calais". We have next to no documentation - with so few units being sold manuals are very rare. The Instruction manual we have is missing some essential pages. The Conqueror, apart form the finals is very similar, some circuits are identical, so the Conqueror manuals have helped. We are within an ace of having it working, and as mentioned above, I would be very interested to hear from anyone with any knowledge, anecdotal or otherwise, of the Challenger. Many Thanks - Michael.
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  #2  
Old 2nd August 2019, 12:41
R651400 R651400 is offline  
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Welcome to SN Michael and hope your search is successful.
1.5Kw transmit power for a cross Channel ferry?
The mind boggles!
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  #3  
Old 2nd August 2019, 15:34
Michael Oceanspan Michael Oceanspan is offline
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I thought it seemed excessive at first, but Board of Trade regulations apply. Vessels over a certain displacement, carrying more than so many passengers (I don't have the actual numbers at my fingertips) were required to carry this equipment.
Michael.
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  #4  
Old 3rd August 2019, 06:37
Paul Braxton Paul Braxton is offline  
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Thanks for your private msg, Michael. Glad to know you got your namesake working. If I ever get my hands on an Apollo, I'll be sure to drop by, look at your manuals. Thanks again.

Paul
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  #5  
Old 3rd August 2019, 12:54
R651400 R651400 is offline  
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Quote:
Originally Posted by Michael Oceanspan View Post
I thought it seemed excessive at first...
The radio regs circa Oceanspan Mk.1 time was British registered ships on 500kc/s communicate with the nearest UK coast station on low power and from memory for the Oceanspan that would've been 25 watts.
Note the engine side of your museum is well represented on you-tube. Any chane of same for the Marine Radio side?
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  #6  
Old 3rd August 2019, 13:20
P.Arnold P.Arnold is offline
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To Michael Oceanspan.
Canít help too much with tech details.

I commissioned 3 Challengers on Southern Shipping Corporation of India, at KSEC shipyard in Busan S.Korea 1985.

The aerials were AS9 vertical with wire emergency across the Monkey Island space. Using the manufactured internal MF taps, you could set up loading for the AS9 aerial MF 410 through to 512khz, but could not get the full range on the wire aerial. You could get 410 to 480 or changing internal taps 454 to 512. Long story short, I added an internal tap between the fixed ones. It did seem to be an easier transmitter to tune, though on MF during sea trials the MF gonio did creep.
The associated RX was the Oceanic, with keypad channel entry as well as the classic rotary tuning knob.

Beyond that I am afraid memory fails me

I used to sign off with No use getting older if you donít get wiser.
I think I used to be wiser

Peter

Revisited your photo, I think the Oceanic RX is in the bottom left of your console.

Last edited by P.Arnold; 3rd August 2019 at 13:23.. Reason: Added info
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  #7  
Old 3rd August 2019, 15:06
Michael Oceanspan Michael Oceanspan is offline
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Commissioning Challenger

Hello Peter,
Thanks for your thoughtful reply. I do intend to write an article on the restoration of our Challenger, and will cover the Challenger history in general by way of background.
With your three for Southern Shipping Corporation, we can account for 6 out of the 12 (or so) Challengers actually sold. However, the provenance of the one in Australia is unkown.
Our antennas are a 40 metre Inverted L for Transmit and a slightly shorter Long wire for receive. We have a stainless HF vertical to add to the antenna farm at some time in the future.
You are right about the Oceanic, although the one in the picture is a fully working example, I am very nervous about using for extended periods. I know this is contrary to shipborne use where it would have been on 24 hours every day. However, at the risk of digressing - we had (still have) another Oceanic, a dead one. Breifly, I believe the pathology before we obtained it was, 1) Stopped working one day, owner probably checked a few obvious things, turned it off and on a few times, 2) Finally disovered that the 5Volt rail had gone sky high, 3) Replaced the 5Volt pass transistor, 3) Still didn't work, sold it to us. I strongly suspect that the 5Volt Pass transistor failed short, rather than open, thus dumping 20(ish)Volts across the 90 odd TTL ics, all of which are soldered in - a nightmare to repair. According to my research, this is not an uncommon failure point with Oceanics. The pass transistor on our working one does get very, very hot, so rather then invite failure I avoid using it at present. A single TO220 style pass transistor for over 90 TTL devices is bound to be struggling. The long term intention is to fit an external, more substantial 5Volt supply with over voltage clamp and current limiting (both omitted from the Oceanic design). Aside from this shortcoming, it is a very capable and pleasant receiver to use.
Michael.
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  #8  
Old 3rd August 2019, 15:34
Michael Oceanspan Michael Oceanspan is offline
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[QUOTE=R651400;
Note the engine side of your museum is well represented on you-tube. Any chane of same for the Marine Radio side?[/QUOTE]

The Radio side is not prominent on YouTube. However see www.gb2mop.org for the Museum's Radio web-site. (MOP: Museum of Power), The Museum's main site is www.internalfire.com
Both sites are in need of some updating, but with only 24 hours per day!!!! For instance, the Oceanspan is now fully operational and inegrated with the associated Atalanta and Mercury receivers.
If you read Practical Wireless, the April 2017 and April 2018 issues have a bit more background on the Museum's Radio activities including the Oceanspan's story.

Michael.
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  #9  
Old 3rd August 2019, 18:58
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GW3OQK GW3OQK is offline  
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I've been several times to the MOP and operated from there on CW. Fantastic smell of hot oil and wonderful sound of those engines, one must be 6m tall. I'm also a musician and ex sparks. Here's a video of me and my best butty at the museum https://www.youtube.com/watch?v=JkrFgSGdICM
73,
Andrew GW3OQK

Last edited by GW3OQK; 3rd August 2019 at 18:59.. Reason: no link
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  #10  
Old 3rd August 2019, 19:09
sparks69 sparks69 is offline  
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Visited there last summer. Magic place and the coffee was good too.
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  #11  
Old 4th August 2019, 00:16
Paul Braxton Paul Braxton is offline  
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Have you legally changed your name to Michael Oceanspan, I wonder?

Such a weirdly wonderful juxtaposition of names!
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  #12  
Old 4th August 2019, 20:56
Michael Oceanspan Michael Oceanspan is offline
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First of all Andrew, thanks for your response. Hazel waxes lyrical about your performance at MOP, for some reason my wife and I were not present on that occasion, I can't remember why, but I have seen the YouTube clip before and recommend it to anyone who wants to escape the modern phenomenon of digital Tape) loops for rhythm section - brilliant. Michael
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  #13  
Old 4th August 2019, 21:01
Michael Oceanspan Michael Oceanspan is offline
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Paul, I'd spent so much time up to my elbows in the Oceanspan's insides that it was first thing that came to mind when asked for a username! Next username will have to include Challenger as over the last few months I have become intimately acquainted with its insides!
Michael.
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  #14  
Old 6th August 2019, 23:07
Paul Braxton Paul Braxton is offline  
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Hi Michael. Oh, I can relate to that. So much time, immersed solidly inside the 'Span at college, trying to find the faults which the instructor had put on; little bits of screwed up paper in relay contacts, missing valves, dud valves; the list went on and on, but boy, did we know all about it by the end! (Well, yes, we did...)

Funnily, on actually sailing with the thing, which I did every trip for the first several years after I started out, with the exception of my first, junior trip when I had the Crusader to try and figure out, there were hardly ever any reasons to go back inside it again. Even when it ran hot after hours of keying, trying to raise Portishead on 12 MHz from the South Pacific. Only fault I can remember was a dud 8MHz crystal, inserted into the spare position on the front panel for working R/T into the agents at Matarani, in Peru. Last thing you might suspect as being faulty. I still have the offender, in a bag of other memorabilia. Strange, what you retain.

You had to be very aware of the weight of the transmitter section, before allowing it to come all the way out at you. 80lbs, if I remember rightly. And you had to be very aware of the lethal 600 volt HT on the three O/P 807's topcaps, of course, which, although thankfully I never had to verify, could apparently throw you across the room, as in the story of some luckless student gleefully and somewhat cruelly, (usually when you were at the teetering point of it coming out of its cabinet), by the instructor, Frank Mayoh, for those who may remember him.

Cocky sod, sometimes, Frank. (Sorry, but you know it's true, if you're listening!) Let me find out the hard way, how hot Z77's in the Salvor actually run, by standing close behind, watching my inept attempts at fault finding, letting me burn my fingers, getting one out: "just to check if it's a dud..." Good days.

I wish you luck with the Challenger, a beast I hadn't heard of until your thread. The Commandant/Conqueror was a beaut, especially after I'd done the 2 week course up in Govan, Glasgow on them. What a joy to have all that power and especially stability after the 'old girl' with the red and blue knobs!

Last edited by Paul Braxton; 6th August 2019 at 23:15..
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  #15  
Old 7th August 2019, 18:19
Michael Oceanspan Michael Oceanspan is offline
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Paul, While not wishing to stray too far off topic, you mention the front panel crystal socket on the Oceanspan. What I've done with ours is feed an Arduino based VFO output into the external Crystal socket, that puts us on the Amateur Bands, but not 14MHz as this falls in the cracks in the 'span's tuned driver circuit. Ours was a VIIE (Emergency) which I reverted to Main Transmitter status. It had the 24VDC Dynamotor which was noisy, so built a 650VDC mains supply which is a bit quieter and doesn't drop 100Volts when transmitting. Both units are heavy, unfortunately we don't have the very rare Marconi extension rails which means we can't work on the transmitter when it is live which is fine for Health and Safety but it make it very difficult to adjust the tuned circuits which, if you remember, are on the bottom of the transmitter. If I could do that it could be put onto 14MHz quite easily!
Back on topic, I think I mentioned that documentation is rare for the Challenger, fortunately we have a full set of manuals for the Conqueror which, apart from the final stages is remarkably similar to the Challenger - sufficiently so to enable me to sort out its last mysteries. (The main console is now giving me headaches!) We are now waiting for parts and hope to have it gracing the airwaves in a few weeks time.
Thanks for comments - Michael.
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  #16  
Old 7th August 2019, 23:03
Paul Braxton Paul Braxton is offline  
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Must be quite a blast, working with all that gear from the venerable Marconi Company. I wouldn't mind getting my hands on some of that again, for old times' sake. Funny you mentioning the extension runners on the Oceanspan. I don't remember them, but I guess we must have had something similar at college.

Hope you get the Challenger up and ready to transmit again soon.

Paul
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