Forums :: Resources :: Features :: Photo Gallery :: Vintage Radio Shows :: Archives
Support This Site: Contributors :: Advertise


It is currently Aug Tue 20, 2019 5:32 pm


All times are UTC [ DST ]





Post New Topic Post Reply  [ 10 posts ] 
Author Message
 Post subject: M.P. Pedersen B 310 maritime receiver
PostPosted: Apr Tue 30, 2019 10:42 pm 
New Member

Joined: Apr Tue 30, 2019 9:20 pm
Posts: 5
Location: Venice, Italy
First of all, please let me introduce myself as this is my first post here: I'm Sergio from Venice, Italy, I'm not an expert in antique/old radio restorations, but I'm 64 and I'm tinkering with radios and electronics since I was a kid. In the past I successfully restored an old BC-342. I'm not an active ham, but I hold my license as well as one of official SWL.

I recently inherited from a good friend of mine an "M.P. Pedersen B 310" maritime receiver, which seems to be quite a fantastic piece of hardware (heavy hardware at more than 30 Kg!) and I'd really like to put it back to work.

I don't know what story of this receiver is, but I suspect it was used on some old tug here in Venice, Italy. Anyway it seems to be a really professional piece of equipment of the kind you expect to find in merchant ships, and I suppose it was build between 1960 and 1965.

The only information I found on the Internet about it and similar receivers of the same make are:

1) a document about how to hook it up to its brother transmitter and some information with a picture of it in an M.P. Pedersen catalog at http://www.peel.dk/MPP/index.html (see: "C 439 A - Main Receiver type B 310 installation wiring diagram" and "Katalog fra M.P.P."

2) something at radiomuseum.org https://www.radiomuseum.org/dsp_herstel ... ny_id=5465

3) a Danish Wikipedia article about M.P. Pedersen: https://da.wikipedia.org/wiki/M.P._Pedersen (quite a chap he was... he set up his first radio tubes factory, illegal at the times in Denmark, disguising it as a cigarettes factory!!!)

So... I'm interested about knowing anything about this model and the company that was making it, if anybody here knows, and it would be really great if someone could share a schematic.

I've shared some pictures I took of my receiver on Google Photos: if you are interested please have a look at them and also feel free to use them as you wish (I'm sharing them with a CC-BY license, so if you wish you're totally free to publish them by just citing me as the copyright owner and that the license is Creative Common CC-BY). Here is the address of my Google album about it: https://photos.app.goo.gl/MDZ3sjHy8aGMPDxf9

As you will see some of the pictures are documenting my first steps into its restoration: there where stripped threads in the chassis where a couple of screws were holding a "bridge" through which two pistons pushed by rotary cams act on the MF coils to set the receiver bandwidth. I changed one of the screws with a brass screw which passes through the chassis and it is held by a brass nut on the opposite side, and the second screw (which goes directly inside one of the MF coils where I cannot put a nut) with a new slightly longer one which seems to perfectly hold.

I hope you find this receiver interesting,

have a nice day!

Sergio

Hey, sorry! I had to "scramble" all external links in my post because as a new user I wasn't allowed to use them: as soon as I'll have received enough good karma I'll try to fix them (but you just can remove extra spaces if you are curious right away!)

Edit: links fixed, thanks for the karma! :D


Last edited by smz on May Wed 01, 2019 12:47 am, edited 5 times in total.

Top
 Profile  
 
 Post subject: Re: M.P. Pedersen B 310 maritime receiver
PostPosted: May Wed 01, 2019 12:24 am 
New Member

Joined: Apr Tue 30, 2019 9:20 pm
Posts: 5
Location: Venice, Italy
My apologies, I just realized this should had been posted in "Vintage Communications Receivers and Transmitters"... :oops:

Not best way to get "good karma points" starting like this... :roll:

Can a moderator please move this thread to the relevant forum? Sorry for the inconvenience...

Sergio


Top
 Profile  
 
 Post subject: Re: M.P. Pedersen B 310 maritime receiver
PostPosted: May Wed 01, 2019 10:27 pm 
Member
User avatar

Joined: Jan Tue 31, 2012 1:55 am
Posts: 9198
Location: Mountains of Mourne. Ireland.
Hello Sergio.

Check your PM (private messages).

Welcome to the forum... :)
Greg.


Top
 Profile  
 
 Post subject: Re: M.P. Pedersen B 310 maritime receiver
PostPosted: May Thu 02, 2019 8:48 pm 
New Member

Joined: Apr Tue 30, 2019 9:20 pm
Posts: 5
Location: Venice, Italy
Thanks to the moderators for having moved this thread to the correct sub-forum!

While I'm here I take the occasion to upload a picture of my baby boat anchor "fully dressed".

Attachment:
M.P. Pedersen B310.jpg
M.P. Pedersen B310.jpg [ 217.98 KiB | Viewed 443 times ]


Being quite a noob at this things, now that "she" is cleaned and in perfect mechanical conditions (beside that meter glass that I'm willing to fix...), what would be your advice as the next step? Check tubes filaments? Condensers? I think she was born around 1960-1965 and probably she hasn't had an electron flowing since at least 25 years: would it be dangerous for her safety to be powered up "right away" (maybe through a Variac, that I have)?

Thanks to whomever might help!

Sergio

P.S.: as I've already said in my first message, more detailed picture are available here: https://photos.app.goo.gl/MDZ3sjHy8aGMPDxf9


Top
 Profile  
 
 Post subject: Re: M.P. Pedersen B 310 maritime receiver
PostPosted: May Thu 02, 2019 10:02 pm 
Member

Joined: Jan Thu 01, 1970 1:00 am
Posts: 3647
Location: Monterey California USA
I think perhaps this was intended for larger vessels since it has a range to cover 500 kHz and the low frequency CW band, which would have required a radio operator who knew CW. It is also rather complicated for untrained people to use, unlike a typical bridge radiotelephone of the time which just had a volume control and channel selector, and maybe an antenna tune control.

The first thing I usually do with things like this is check the power supply filter capacitors for leakage and shorts. Sometimes on professional equipment they are high quality and still good. Other times, not. Then I check a couple of the paper capacitors for leakage. If they are good, I then power it up and go from there. If the sample capacitors test bad, then I know I need to replace all of them first.

I couldn't tell whether this is 230V AC mains powered or a ship DC powered set, such as 110V DC or 32V DC' If it is mains powered, you would be ready to go!

_________________
WB6NVH
California Highway Patrol Radio
Bell System Mobile Telephone History
http://www.wb6nvh.com


Top
 Profile  
 
 Post subject: Re: M.P. Pedersen B 310 maritime receiver
PostPosted: May Thu 02, 2019 11:07 pm 
New Member

Joined: Apr Tue 30, 2019 9:20 pm
Posts: 5
Location: Venice, Italy
Hi Geoff, thanks for helping!

Yeah, you're probably right, my anchor has probably served on a bigger ship than a tug...

About powering it up and what kind of juice it will like... I'm really confused.

If you look at this page from of the Pedersen catalog it seems that the receiver could be available with different powering options: 110 or 220 volts AC or DC:

Attachment:
B 310 - Catalog page.jpg
B 310 - Catalog page.jpg [ 76.49 KiB | Viewed 422 times ]

(BTW, the catalog picture does not correspond to my receiver's front panel: loduspeaker is missing and the meter and its switch are swapped)

On the receiver there is a "power module" inserted into an octal socket with 10 pins (is it "decal"?).
The module is apparently composed of a transformer, an impedance a couple of big condensers (wax covered), some resistors, an impedance and a tube (... stir and serve ...).
Unhappily the tube is the only one in the receiver whose type is not indicated on the chassis and of course, according to Murphy's law, it is also the only one whose type cannot be read on the glass.

Attachment:
B 310 Power module.jpg
B 310 Power module.jpg [ 128.31 KiB | Viewed 422 times ]


The only document I found about the B 310 is an "Installation Wiring Diagram" and there it seems that the receiver should be powered by 110V AC from the transmitter (but I don't understand the meaning of the "24 V DC Keyed" indication....):
Attachment:
B 310 Installation Wiring Diagram.jpg
B 310 Installation Wiring Diagram.jpg [ 92.51 KiB | Viewed 422 times ]


Don't be fooled, as I initially was, by the aluminum cylinder with the "110V 15W" indication: that's connected to the antenna input and apparently it is a "lamp". See the diagram of a similar Pedersen receiver's RF stage I found on the net (of course because of Murphy I couldn't find mine!):
Attachment:
B 285 RF stage.jpg
B 285 RF stage.jpg [ 178.83 KiB | Viewed 422 times ]


Maybe the safest course of actions could be to part the power module from the receiver and start debugging it... what do you think? Actually I had already done that if only I had a "decal" socket to insert it in "off-line", but of course I could try and solder some wire directly on the decal plug of the power module, only concern being that I hope to not ruin it and that it will then still insert smoothly into the receiver socket as it does right now...

Cheers!

Sergio


Top
 Profile  
 
 Post subject: Re: M.P. Pedersen B 310 maritime receiver
PostPosted: May Fri 03, 2019 6:28 am 
Member
User avatar

Joined: Mar Mon 17, 2008 5:05 am
Posts: 5700
Location: Ashhurst, New Zealand
Quote:
It is also rather complicated for untrained people to use,


I joined the South African ship, the "Allamanda" in Rotterdam on the 28th April 1966 as the Radio Officer (it says in my Discharge Book!) and found all the radio room gear was made by Pedersen - the ship was previously the "Evelyn Maersk", a Danish tanker. I don't recognise the B310, the radio room fit was probably from earlier equipment but it all worked well after I got some help from the Danish handover engineer - all the front panel labels on all the equipment was Danish of course! Two excellent Amplidan morse keys, I managed to buy one on our local auction site.

Anyway - the 28v 'keyed' is to desensitise the receiver when the accompanying transmitter is keyed, you don't want to damage the receiver from a kilowatt or so of RF nearby - usually the receiver antenna comes via the antenna keying relay in the transmitter and so is normally disconnected - also the receiver AGC is biased off to prevent any noises in the operator's headphones - sidetone comes from the transmitter. There is a delay in the antenna relay to prevent it chattering when sending morse but not too long as to miss a quick reply. One of the advantages of the receiver antenna coming via the transmitter is that the receiver is also tuned by the transmitter antenna coupler to get the best signal - no 50ohm coax, it's usually bare copper tubing out to the "T" or "inverted L" antennas, depending on the configuration of the ship. You can see the open door at the rear of the bridge deck, that was the radio cabin on the port side and my cabin on the starboard.

https://www.balticshipping.com/vessel/imo/5110161

Attachment:
EVELYN MÆRSK (1) @mærsk.jpg
EVELYN MÆRSK (1) @mærsk.jpg [ 283.98 KiB | Viewed 378 times ]

_________________
Cheers - Martin ZL2MC


Top
 Profile  
 
 Post subject: Re: M.P. Pedersen B 310 maritime receiver
PostPosted: May Fri 03, 2019 3:55 pm 
Member

Joined: Jan Thu 01, 1970 1:00 am
Posts: 3647
Location: Monterey California USA
I forgot that it would probably be an AC-DC receiver, such as the RMCA AR-8506, as was used on many freighters from 1940 into the 1950's. Therefore there is no power transformer. I am thinking the 15W lamp is a protection device for the antenna coils which keeps them from burning out in the event the antenna comes in contact with the hull of the ship and there is an AC input wiring fault. This, because I see the circuit grounds are tied directly to the chassis and housing of the receiver, and it is an AC-DC design. The RMCA design of the AR-8506 "floats" the circuit grounds throughout the set and does not connect them directly through the chassis. Most of the shipboard receivers of that era (all?) were AC-DC and had no power transformer.

I think the decal (10 pin) "tube" may be actually a "ballast" tube which allows the set to run on 220 V AC, and is a resistive element that drops 110V with some regulation (hence the name "ballast.") Otherwise there would have to be a bank of resistors somewhere to change from 220 to 110 Volts.

Being that there is no transformer to worry about, you could power it up right away. I would just want to make sure it is configured for 220V, because if it is still set to 110V, you would blow all the tube filaments! Seeing that one side of the line appears to be connected directly to the chassis, I am thinking that for home use I would use an isolation transformer, either 220-220 or 220-110 V, for safety.

_________________
WB6NVH
California Highway Patrol Radio
Bell System Mobile Telephone History
http://www.wb6nvh.com


Top
 Profile  
 
 Post subject: Re: M.P. Pedersen B 310 maritime receiver
PostPosted: May Fri 03, 2019 5:04 pm 
New Member

Joined: May Thu 17, 2018 12:16 am
Posts: 13
Location: Edmonds, WA USA
Try putting the mystery tube in a freezer then remove and blow on it. Sometimes that reveals the tube type lettering.
Dave

_________________
Dave
W7VM

Real Radios Glow in the Dark


Top
 Profile  
 
 Post subject: Re: M.P. Pedersen B 310 maritime receiver
PostPosted: May Tue 07, 2019 1:48 pm 
New Member

Joined: Apr Tue 30, 2019 9:20 pm
Posts: 5
Location: Venice, Italy
Thanks to all who contributed and my apologies for the late answer but I've been busy with family obligations (and moderately ill as well!).

@majoco:
great story! You radio officers have all my respect and I think young people should know more about what it meant to communicate while at sea at times where satellites and the Internet weren't available. Slightly related, I grow up in a family where both my maternal grandparents, from Genova, were telegraphists, working for Italcable (at the times the sole Italian long distance telecommunication operator). My grandma was a Morse operator and she taught me code when I was about a first grader (7-8 years old, probably). Unhappily I've totally lost the skill. Grandpa died when I was really young and I can't remember much about him (just some "flashes"), but grandma told me about him and how he was a Baudot operator before teletypes were available and that to transmit code he had to use what seemed to be a 5-keys "piano keyboard" to compose the codes. Grandma also told me stories about the Andrea Doria sinking and how some days after that she was on duty receiving information about rescued passengers and crew and how she received news about a grandpa's brother who was on board as a woodworker (he was well...). Grandma lived to 102 years and she was amazed when in 1995 I showed her what the Internet was (at the time I had set up one of the first Italian ISP...).


@Geoff Fors:
sorry if I haven't been clearer: the decal socket doesn't hold the mystery tube, but the whole "power module" (the sub-board with the two transformer-like objects, one of which is marked MPP, the tube and some other components). The tube itself is of the "rimlock base" type, like all other tubes in the receiver.
Good information about maritime receivers of the era being of the AC-DC types: that's something I suspected (from reading other information about other MPP receivers), but I wasn't totally sure about. What was the rationale for using such design for ship-borne receivers?
Yes, I'll surely follow your advice and I'll use an insulation transformer, in front of my Variac, to try and power up "the beast". I don't have one right now but I think I could use a pair of halogen lamps 220 to 12 V transformers I have by connecting their secondaries together, back-to-back, right?
Anyway I've decided I'll try to figure out the schematic of that "power module" before anything.

Which brings me to...
@Lolyn:
Wow! That's a great trick Dave! I'll try that!

It's fantastic how much knowledge and wisdom is available from this community!

I'll let you all know how it will goes when I'll proceed. In the meanwhile thanks again to everybody.

Sergio


Top
 Profile  
 
Post New Topic Post Reply  [ 10 posts ]  Moderator: Sandy

All times are UTC [ DST ]


Who is online

Users browsing this forum: No registered users and 5 guests



Search for:
Jump to:  




























Privacy Policy :: Powered by phpBB