Poor HF reception on 16 - 28MHz band - Page 2 - Ships Nostalgia
05:21

Welcome
Welcome!Welcome to Ships Nostalgia, the world's greatest online community for people worldwide with an interest in ships and shipping. Whether you are crew, ex-crew, ship enthusiasts or cruisers, this is the forum for you. And what's more, it's completely FREE.

Click here to go to the forums home page and find out more.
Click here to join.
Log in
User Name Password

Poor HF reception on 16 - 28MHz band

User Tag List

Reply
 
Thread Tools
  #26  
Old 22nd September 2019, 22:59
Paul Braxton Paul Braxton is offline  
Senior Member
Organisation: Merchant Navy
Department: Radio Officer
Active: 1969 - 1982
 
Join Date: Jul 2005
Posts: 301
Thanks Freddy, for that gem of information.

I can't get over how useful this site really is. Who'd have thought, someone who knows someone from Mimco who actually has the know-how on the old Atalanta! That is truly amazing.

I do have the manual for it, so will do as you suggest, see what happens. I replaced the two RF amps with new valves and there does seem to be an improvement, although not a huge one. As you say, it could be down in part, at least, to propagation conditions. Let you know how I get on, once I get my hands on the appropriate resistor, that is.

Regards, and thanks, Paul
Reply With Quote
  #27  
Old 28th September 2019, 22:21
Paul Braxton Paul Braxton is offline  
Senior Member
Organisation: Merchant Navy
Department: Radio Officer
Active: 1969 - 1982
 
Join Date: Jul 2005
Posts: 301
Martin! (#24)... Didn't see your post, all the way from the Manawatu. Sorry, but 73's to you, too. CFH was Halifax, N.S., wasn't it? Good work with your aerials and so forth. I wouldn't have the knowledge, now, to know how to do all that.

Freddy (#25)... Changed the 22k high stab resistor (R100), in the screen feed for V1 and V2, a nice little job, getting my hands down and dirty inside the old set. (Actually, she's in near perfect condition inside, no sign of any dirt, cobwebs or the like, and all joints still in factory mode, all with the signature red mark on each soldered joint). A bit hard to melt the old solder at first, but not having a high wattage iron, I have to 'start it' with fresh solder, then it's O.K. When I removed the old R100 and put it on the AVO to test, found out that I'd have to fix my test equipment first! Battery compartment problems, leakage from a D cell in there had spread a solid encrustation of beautifully blue-coloured crystals everywhere. Could hardly even scrape it off, so had to dismantle the entire meter, now on the work bench awaiting further work today. My little digital meter, unused for many years, still seemed to be working enough, although intermittently, showing the original resistor at what seemed to still be 22k.

Replaced it anyway, and now I seem to be getting far better reception on the two 'top' bands - 6 to 15MHz and 15 to 28MHz. The latter band has been virtually silent for many months, with only very strong b'cast signals coming through at night, but now there's a lot going on again, all the way along to the top end. Picking up the air traffic HF from Nandi, Brisbane and Auckland again, as well as the aircraft themselves on 8MHz. last night. Not at all sure what part varying propagation conditions may be playing here, but I suspect that the new RF valves and now a new screen resistor has been the main factor in the better performance.

Interesting, too, in the fact that the SSB signals from the above sources, as well as amateurs, don't seem to drift nearly as much as they always have done since I first had the set. I was able to leave the air traffic frequency and go and have tea last night, listening to whatever came on over the TV sound in the lounge, and blow me down, the set seemed hardly to drift at all. In fact, the voices were still coming through virtually with the same degree of intelligibility as at the start. Previously, I would have had to sit there, twiddling the fine tuning control virtually constantly, just to maintain intelligibility. Whether that's anything to do with the earthing on the tuning caps or not is not known, but I suppose might well be.

Anyway, thanks again for your ideas on that, and thanks to your friend, too, for his recollection of a stock fault from Mimco days. I would love to know the history of my set, whether it was ever on a ship, and if so, which, as well as how old it is. There's no mod label, and the Marconi metal name badge contains the name Atalanta integrally within it, not separately, on a black rectangle underneath, as the newer ones had in my recollection. I have a photo of one on the old "Icenic"/GHHH, which had what I think must have been the newer badging, and that dated from late '74, so I have a clue there that maybe my RX dates back to before that era. Don't suppose there's any way of finding out, there probably not being any records still extant.

But thanks again for your interest, and giving me the chance to do some real work again with a soldering iron and a set built to last forever-more, it seems.

73's from Kaharoa, NZ. Best regards, Paul

Last edited by Paul Braxton; 28th September 2019 at 22:28..
Reply With Quote
  #28  
Old 29th September 2019, 21:33
freddythefrog freddythefrog is offline  
Senior Member
 
Join Date: Dec 2007
Posts: 544
Cool

Hi Paul
Great news of your success with the Atalanta Rx and hearing more stations on the higher H/F bands.
I will pass your best wishes to my colleague TOM Stub, ex GTZM R/O
and shoreside tech.
When I originally asked him he said he could not remember what he had for breakfast that day never mind what the fault was as its 50 years ago
since he last working on Atalantas!! Anyway he did remember after all.
He and I were both at Riversdale tech together on pmg and radar courses before joining GTZM.
I do not know whether or not if Marconi kept serial numbers of their radio gear assigned to ships, but maybe best if you ask Ron Stringer
ex GTZM who is on this site as he has a vast knowledge of most things about GTZM. Enjoy your listening Paul. Cheers 73.s de ftf
Reply With Quote
  #29  
Old 29th September 2019, 23:40
Ron Stringer's Avatar
Ron Stringer Ron Stringer is offline
Senior Member
Organisation: Merchant Navy
Department: Radio Officer
Active: 1960 - 1966
 
Join Date: Mar 2005
My location
Posts: 6,229
Quote:
Originally Posted by freddythefrog View Post
.... ask Ron Stringer ex GTZM who is on this site
Well the original delivery notes accompanying the equipments to the ship would have had the serial numbers recorded on them. A copy would have been kept in the Supplies Department or depot stores and the ship's file. However those records will have long been disposed of. At Chelmsford, after we moved from the MIMCo HQ building Elettra House, firstly to a MCSL site at Waterhouse Lane for a few years and then to Building 720 in the main Marconi New Street estate, all non-essential documentation was dumped.

This was for no other reason than that, with each move, the space we were allocated at our new location was a fraction of that which we were currently occupying. We could either accommodate essential people and equipment or the accumulation of several decades of paper records (which by then occupied a greater space than the much-reduced workforce). All paperwork not required to be kept by law, or directly connected to 'live' contracts, was simply skipped - several tons of it.

Once the records had gone there was an immediate saving to be made by redeploying the clerical staff involved in keeping them maintained. A win-win solution for the bean counters.

So there will be no existing record of which bit of kit went on each ship, interesting though such information would be to the likes of us and future industrial historians.
__________________
Ron
_____________________________________________

Never regret growing older. It is a privilege denied to many. Don't worry about old age - it doesn't last.
Reply With Quote
  #30  
Old 30th September 2019, 17:51
freddythefrog freddythefrog is offline  
Senior Member
 
Join Date: Dec 2007
Posts: 544
Hi Ron
Many thanks for that excellent piece of information ref GTZM and the unfortunate dumping of a sea of information.
I hope Paul in N.Z. reads this and it will save him searching in vain for the lost info re his Atalanta Rx.
Cheers 73.s de ftf
Reply With Quote
  #31  
Old 30th September 2019, 21:42
Paul Braxton Paul Braxton is offline  
Senior Member
Organisation: Merchant Navy
Department: Radio Officer
Active: 1969 - 1982
 
Join Date: Jul 2005
Posts: 301
Thanks for your informative post, Ron. It's more or less as I would have expected. If only all or some of that information about the Mimco equipment could have been archived on a computer hard drive. Ah well, I'm pleased the old girl is still completely operational after all this time. That's the main thing.

Thanks for your interest again, Freddy.

Paul
Reply With Quote
  #32  
Old 4th October 2019, 00:24
djringjr djringjr is offline  
Member
 
Join Date: Feb 2008
Posts: 27
This is the best site for software defined receivers:
https://sdr.hu/

There's a map showing locations, but many locations are off on the map.

Best wishes,

David Ring
ex Radio Officer
U.S. Merchant Marine also at Tuckerton, NJ radio/WSC,
Reply With Quote
  #33  
Old 4th October 2019, 01:55
duncs duncs is offline  
Senior Member
 
Join Date: Sep 2008
Posts: 435
I found the Atalanta rx very reliable, but the Mercury and Elettra had a habit of blowing a de-coupling capacitor in FS. After the first time it happened, all I did was sniff it out, then snip it out, not replaced. no prob.
Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off




Support SN


Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
User Alert System provided by Advanced User Tagging v3.1.0 (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.