UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio Service Data

Go Back   UK Vintage Radio Repair and Restoration Discussion Forum > Specific Vintage Equipment > Vintage Amateur and Military Radio

Notices

Vintage Amateur and Military Radio Amateur/military receivers and transmitters, morse, and any other related vintage comms equipment.

Reply
 
Thread Tools
Old 8th Apr 2020, 11:22 am   #21
ORAWA01
Hexode
 
Join Date: Apr 2011
Location: Stirlingshire, UK.
Posts: 344
Default Re: Marconi C100 B28 vs. Eddystones

CR100 sounds quite good on this video.

https://www.youtube.com/watch?v=WBeymCP_-xA

https://www.youtube.com/watch?v=V0yVh1IoEt0

https://www.youtube.com/watch?v=CGnIenF_ymo
__________________
ORAWA = Old Radios And Wire Antennas

Last edited by ORAWA01; 8th Apr 2020 at 11:32 am.
ORAWA01 is offline   Reply With Quote
Old 8th Apr 2020, 12:08 pm   #22
Radio Wrangler
Dekatron
 
Radio Wrangler's Avatar
 
Join Date: Mar 2012
Location: Fife, Scotland, UK.
Posts: 14,106
Default Re: Marconi C100 B28 vs. Eddystones

I remember looking in awe ar an EA12 in Jim Fish's shop. Then years later at a KW201. My AR88 seemed very old fashioned.

200 seems a very good price, though it's a long way from you. I can't remember what I paid for it in the late eighties. One of our local club members had got it out of the attic and asked me if I could check it over and check the alignment. Job done, I returned it to Alec and he asked what he owed me. I'm not in the repair business, I do things for friends or out of curiosity. He said he didn't want to sell it without knowing it was OK. Sell it! whatever for? I asked he said he wasn't using it and wanted to run his equipment down to what the actually used. I said I'd like to buy it. He said I could have it. It took a lot of doing to get him up to a price where my conscience would be OK. So that's how I wound up with my schoolboy crush!

It's pretty common for EA12s to have a crack across the internal S-meter plastic front. Eddystone made the offset joggle in the front panel too small and the S meter is pulled back by its mounting screws onto the points of the corners of the clear meter front. With this stress, cracks are almost inevitable.

Oh, by the way, they tune backwards but you get used to it.

Only covers the six pre-WARC HF bands.

If you don't add rubber feet they scratch the hell out of tables and you can tear yourself badly on the corners of the tilt bracket. Watch out.

I found a copy of the G2DAF pamphlet in Miss Taylor's emporium and devoured it avidly. Wow! this was IT! but I couldn't afford the 898 drive. I could have done the metalwork without any bother, but the cost of new IFTs and all those crystals. Yipes. Also I heard distant rumours of something called an RA17 which was frequency synthesised - whatever that was, it sounded impressive. Synthesised? Did that mean it didn't do real frequencies, only synthetic ones? Whatever those were? I never did see one for many years, and I could never have afforded one.

Back to the which boar anchor should you get.

The EA12 is lovely, but is being tied to the amateur bands what you want? THe rest of the HF bands are emptying as broadcasters move to the internet.

I think everyone ought to have an HRO or AR88 at some time. Get it sorted and you won't have to move it!

The CR100 will leave you wondering what it would have been like if you'd got that HRO/AR88

There are other gorgeous boat anchors around like the AR8516L our village pharmacist in Yorkshire had. Another wow set. But I think I like the electronics better of the CRM-R6A version.

All the world's a toyshop.

David
__________________
Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done
Radio Wrangler is offline   Reply With Quote
Old 8th Apr 2020, 12:28 pm   #23
deliverance
Hexode
 
Join Date: Apr 2015
Location: Manchester, UK.
Posts: 379
Default Re: Marconi C100 B28 vs. Eddystones

As others have stated the AR-88 is a good choice the Eddystone 730/4 also the BRT-402 running on 110 volts . If you can find one for a reasonable price the Collins R-388 .
deliverance is offline   Reply With Quote
Old 8th Apr 2020, 12:38 pm   #24
wd40addict
Heptode
 
wd40addict's Avatar
 
Join Date: May 2009
Location: Stevenage, Herts. UK.
Posts: 790
Default Re: Marconi C100 B28 vs. Eddystones

A friend of mine had several of the sets under discussion, namely RA17, AR88, early Eddystone dual superhet with half moon dial (model number unknown) and CR100.

In my opinion the Marconi was behind the other three in performance. I actually then sought out an RA17 and an AR88. The AR88 worked (just) but its size and weight meant I never got round to giving the TLC it deserved and I passed it onto another collector who got it up and running.

The RA17 I have till this day and you can see how I house trained it in this thread: https://www.vintage-radio.net/forum/...d.php?t=105924

I have in the past owned a lesser Eddystone in the form of the 840c, but it wasn't in the same league as the 'half moon' unit. Maybe some Eddyfan would know the model number?
wd40addict is offline   Reply With Quote
Old 8th Apr 2020, 1:02 pm   #25
ORAWA01
Hexode
 
Join Date: Apr 2011
Location: Stirlingshire, UK.
Posts: 344
Default Re: Marconi C100 B28 vs. Eddystones

Yes, AR88, EA12, RA17 would be really nice. But they are more expensive, and the EA12 is in Southampton for Collection only sale. Too far away from me.

The CR100 was dropped off at my door by the seller, returning from his family funeral. The set including delivery was 50. I couldn't resist it. If it was couriered, the shiping cost would have been 25- 30 I am sure. So, unexpectedly I am a new owner of this 60+ year old CR100.

It looks it needs some work done before powering on. 4x valves are missing, but there are 10 valves supplied with the set along with the original manual / service book. All the controls are moving smoothly, but there is no power lead with the set.

In a way, I feel this is a good set to work on due to its simplicity and having more room inside the chassis compared to the other sets. AR88, EA12 would be too sophisticated for me to work on. And RA17 would be more so. I like sets that are easy to work on with the basic tool set = just a soldering iron and multimeters.

CR100 is not heavy as R107. I was able to lift it by myself, and brought into upstairs my radio / man cave room without any aid.

It was not possible to transport the R107 unto the upstairs radio room due to weight, so it had to be placed in downstairs spare room at the time.
The R107 was a great set. Now I regret having sold it.
__________________
ORAWA = Old Radios And Wire Antennas

Last edited by ORAWA01; 8th Apr 2020 at 1:17 pm.
ORAWA01 is offline   Reply With Quote
Old 8th Apr 2020, 1:21 pm   #26
HamishBoxer
Dekatron
 
HamishBoxer's Avatar
 
Join Date: Aug 2007
Location: W.Butterwick, near Doncaster UK.
Posts: 7,292
Default Re: Marconi C100 B28 vs. Eddystones

I was lucky re my R107,I deposed of it and many years later had a very nice one given to me which I still have.
Re the CR range ,I had CR100 ,CR150 and a CR300 which I believe went to someone on the forum years ago.
__________________
G8JET BVWS Member and V.M.A.R.S
HamishBoxer is offline   Reply With Quote
Old 8th Apr 2020, 1:26 pm   #27
ORAWA01
Hexode
 
Join Date: Apr 2011
Location: Stirlingshire, UK.
Posts: 344
Default Re: Marconi C100 B28 vs. Eddystones

Quote:
Originally Posted by Radio Wrangler View Post
The AR88 is useable to receive SSB but hasn't the selectivity to handle close adjacent signals. On narrow BW it's very pleasant for CW. No product detector so the BFO deafens the AGC system and you must nurse the RF gain manually.

THe HRO is an equal of the AR88. Poor tuning resolution in MHz from those little graphs, but good resettability from that dial. It's maybe a little better than the AR88 at handling the presence of large signals. Same comments about SSB apply to HRO as AR88.

The Eddystone general coverage sets are fair, but not quite as well built mechanically as the AR88. Their much vaunted tuning reduction is fine, but a little wear in the plain brass bush of the tuning knob shaft allows it to rock a little and that produces a frequency shift equal to a fair amount of rotation. I've had to make new bushes for a few of these receivers. Again, they don't really have the selectivity/agc for SSB but can be made to work under favourable circumstances and with effort.

To do SSB on an Eddystone, Tanuki wants an 888A amateur bands only set. I have one of the later versions of it, the EA12. I think in a previous life this one served as the IF for the first moonbounce 70cm contacts out of Scotland. This has an 85kc IF and a notch. SSB reception is easy, performance is fairly good Selectivity is not as sharp as modern SSB radios. THey seem to be sought after, so prices are pretty high.

If considering valve boat anchors, then the Racal RA17 should be in contention. It's fine for AM, RTTY and CW. You can make it receive SSB and it's not too hard work, but add Racal's external SSB/ISB adaptor and it becomes rather good. Superb stability. Long and linear tuning scales (60 inches per MHz) I ran an RA117 for about ten years. That's a later version with a few improvements and a much better amount of audio power.

They've all got their individual charms and difficulties. They can all be fun.

I'd definitely avoid an AC/DC eddystone.

A lot of CR100 have been mucked about with in attempts at improvement. AR88 and HROs tended to get left as they were.

I've had a wide range of receivers over the years... the ones I've kept are:
AR88 (and one for spares)
Eddystone EA12
Racal RA1217 (Transistorised RA117 with SSB filters)
Racal RA1792 (built down to a cost, no preselector or RF filtering)
Icom R-9000 (30KHz to 2000MHz with spectrum CRT)
Icom IC-765 tranceiver
Icom IC-7700 transceiver.

Hope this gives you a bit of a feel for things.

EDIT: Update, RA117 weighs 67 pounds according to data plate on front.

David GM4ZNX
But aren't all the sets with BFOs are not the best for SSB reception? They are good for CW. I think I read somewhere on this.

I have an old ICOM IC-751A, and it still works great albeit with some problems on CW Txing output power.
IC9000 would be awesome, but if it has to be restored, replacing 90+ electrolyc capacitors will be a major project itself.
__________________
ORAWA = Old Radios And Wire Antennas
ORAWA01 is offline   Reply With Quote
Old 8th Apr 2020, 1:31 pm   #28
GW3OQK Andrew
Pentode
 
GW3OQK Andrew's Avatar
 
Join Date: Apr 2011
Location: Swansea, Wales, UK.
Posts: 121
Default Re: Marconi C100 B28 vs. Eddystones

I fixed a fault on my CR100 yesterday. Receiver dead, R39 burnt out, due to perished black insulation so shorting out the screen HT. Previous couple of faults was also perished insulation. It's a pity the IF bandwidth isn't narrower for CW.

73, Andrew
GW3OQK Andrew is offline   Reply With Quote
Old 8th Apr 2020, 1:46 pm   #29
Julesomega
Heptode
 
Julesomega's Avatar
 
Join Date: Dec 2012
Location: Stockport, Greater Manchester, UK.
Posts: 658
Default Re: Marconi C100 B28 vs. Eddystones

Quote:
Originally Posted by dave walsh View Post
I had a DST100 once-cast iron, very rare and weighing 100lbs! The Tuning Dial was a Brake Drum or very similar
I had to google for DST100, gosh, want one, and an R206 MkI

DST100 MkIII

R206 MkI
__________________
- Julian

It's good here
Julesomega is offline   Reply With Quote
Old 8th Apr 2020, 2:06 pm   #30
Gridiron
Hexode
 
Join Date: Apr 2010
Location: West Midlands, UK.
Posts: 309
Default Re: Marconi C100 B28 vs. Eddystones

According to the article on the CR100 in Radio Bygones No 31 by George Grisdale (who was on the design team) besides the usual faults of dried up smoothing caps, etc, the bakelised linen tagboards can absorb moisture affecting the AVC action and wires running under the BFO screening box are a source of shorts.
I have a CR100 which had problems with shorting by crumbling rubber wiring when I first had it, I only use it for listening to broadcast stations, its still working well.
Gridiron is offline   Reply With Quote
Old 8th Apr 2020, 2:42 pm   #31
Radio Wrangler
Dekatron
 
Radio Wrangler's Avatar
 
Join Date: Mar 2012
Location: Fife, Scotland, UK.
Posts: 14,106
Default Re: Marconi C100 B28 vs. Eddystones

Quote:
Originally Posted by ORAWA01 View Post
But aren't all the sets with BFOs are not the best for SSB reception? They are good for CW. I think I read somewhere on this.
A normal SSB receiver has a 'Carrier insertion oscillator' which is usually a crystal oscillator offset from the IF filter and fed into a mixer (usually called a product detector in this position) where it converts the SSB signal in the IF down to audio.

A CW receiver has the same structure, except it is usual to have the 'carrier insertion oscillator' a variable frequency one. This allows the operator to vary the tone of the signal he's listening to for best comfort, and to move it around for a bit of variety. The variable CIO is usually called a BFO

The receiver intended for CW needs to have a wide enough IF to let an SSB signal through (about 3kHz compared to 200-600Hz for CW) and you just need to set the BFO for the right amount of offset on the appropriate side of the IF for USB/LSB and off you go.

Presence of a BFO doesn't mean a receiver can't do SSB, it may mean that it's a bit more work, that's all.

David
__________________
Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done
Radio Wrangler is offline   Reply With Quote
Old 8th Apr 2020, 2:56 pm   #32
Radio Wrangler
Dekatron
 
Radio Wrangler's Avatar
 
Join Date: Mar 2012
Location: Fife, Scotland, UK.
Posts: 14,106
Default Re: Marconi C100 B28 vs. Eddystones

The DST100 was a secret radio whose existence was kept hush-hush until long after it had been left far behind. It was said to be lousy for tuning around, searching, but great for sitting on a difficult signal.

THe other radio which was confidential for many years was the Collins R390. Get a load of all the gears and cams in the permeability tuned preselectors!

David
__________________
Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done
Radio Wrangler is offline   Reply With Quote
Old 8th Apr 2020, 3:25 pm   #33
turretslug
Dekatron
 
Join Date: Nov 2011
Location: Surrey, UK.
Posts: 3,248
Default Re: Marconi C100 B28 vs. Eddystones

I was going to say, if you like the idea of a CR100 then by all means get one as it'll be good valve background and learning curve and at worst you won't lose a fortune- but you're one step ahead!

The first valve radio I ever overhauled (as opposed to ignorantly dismantling as a little 'un....) was a CR100, so there's a certain affinity. I'd played around with various domestic sets with the typical 6-18MHz SW band, mostly transistor portables but a few valve table radios/radiograms belonging to older relatives, and was hooked by this window on the world. Whatever was in all those other gaps between LW and 30MHz, oh to get hold of a real communications receiver. Reading the then-current electronic mags and books was discouraging, this was the late '70s/early '80s, i.e. peak "valve dissing"- they were fragile, wasteful, inefficient, dangerous, valve oscillators were uselessly unstable, valve mixers hopelessly noisy etc. etc., it seemed astonishing that anyone had ever been able to receive anything on a valve receiver! I had a little experience and a considerable hunch otherwise, though, and a good deal of sceptical stubbornness.

My physics lab at school was chucking out long-ignored and dusty old books by the hundredweight, including pre-war radio theory and practice books. I devoured these with fascination and it wasn't long before a local small-ad offered a CR100 from a down-sizing amateur. I went round, it was demonstrated working and I went home with hefty radio and an assortment of spare bottles. Undoing the base-plate and horror! crumbling rubber-insulated wire everywhere, including mains and HT AC feeds.... Nothing for it but a full re-wire and re-build. Over a couple of months, I did an hour or two every now and then, wire-wooling the bare chassis to a gleaming brightness and building it all up again starting from heater chain. IFTs and coil-boxes were scrubbed-up and rewired, and initial switch-on was joyfully flawless. My physics teacher lent me a prized PM5326 and a school lab Telequipment was quietly borrowed for a painstaking but absorbing and fruitful re-alignment. One thing that attracted me to the CR100 was the wide coverage and this set was no slouch, everything from the put-put-put on 60kHz to strong and clear 11m broadcasts came in well and consistently. It was always a drifter, though- fitting an 0B2 108V stabiliser greatly helped the short-term local oscillator stability and including the mixer screen-grid in this supply helped further, but long-term thermal drift was always a weakness. It really needed a couple of hours before SSB use became realistic. My main interest was international broadcast listening though, rather than amateur radio use, and the CR100 was great for that.

I actually still have it, in a corner of the (dry) garage, long-unused and embalmed in bin-bags and covered in component boxes and all the usual garage-fare. It was displaced by an AR88, probably a familiar story, its uncanny frequency stability contrasting with the steadily-wandering CR100. Must unravel it and power it up during these quiet times.
turretslug is offline   Reply With Quote
Old 8th Apr 2020, 3:59 pm   #34
ORAWA01
Hexode
 
Join Date: Apr 2011
Location: Stirlingshire, UK.
Posts: 344
Default Re: Marconi C100 B28 vs. Eddystones

Quote:
Originally Posted by Radio Wrangler View Post
Presence of a BFO doesn't mean a receiver can't do SSB, it may mean that it's a bit more work, that's all.
Greatly put.

Yes, they can do SSB, but not as well / easy as dedicated LSB and USB rigs maybe? As you said, a bit more work is needed, but in some cases it becomes challenging in noisy band and in weak signals. So, some says BFO sets are not designed for SSB, and some might EVEN say "poor"?
__________________
ORAWA = Old Radios And Wire Antennas

Last edited by ORAWA01; 8th Apr 2020 at 4:11 pm.
ORAWA01 is offline   Reply With Quote
Old 8th Apr 2020, 4:05 pm   #35
ORAWA01
Hexode
 
Join Date: Apr 2011
Location: Stirlingshire, UK.
Posts: 344
Default Re: Marconi C100 B28 vs. Eddystones

Quote:
Originally Posted by turretslug View Post
I was going to say, if you like the idea of a CR100 then by all means get one as it'll be good valve background and learning curve and at worst you won't lose a fortune- but you're one step ahead!
...
I actually still have it, in a corner of the (dry) garage, long-unused and embalmed in bin-bags and covered in component boxes and all the usual garage-fare. It was displaced by an AR88, probably a familiar story, its uncanny frequency stability contrasting with the steadily-wandering CR100. Must unravel it and power it up during these quiet times.
Great story on CR100. Thanks TS.

Now I have CR100, which was dropped by the seller like a bombshell. I couldn't resist or avoid it. It was meant to be, I feel. It was only last night, I was thinking about CR100, and contacted this seller reasonably local to me. But I had to go and collect it.

But with the current situation, I couldn't go and collect it as it was not absolutely necessary. I thought I will maybe look for something that could be delivered even if I must pay for the carriage which might be quite high for the weight and size of these things.

I was then told, he could drop it off returning from his family funeral, because my house is on the way to the place. I said, OK thanks - that's the deal.

And this afternoon, the CR100 turned up at my door.
__________________
ORAWA = Old Radios And Wire Antennas
ORAWA01 is offline   Reply With Quote
Old 8th Apr 2020, 4:20 pm   #36
deliverance
Hexode
 
Join Date: Apr 2015
Location: Manchester, UK.
Posts: 379
Default Re: Marconi C100 B28 vs. Eddystones

Well done getting the CR100 .
deliverance is offline   Reply With Quote
Old 8th Apr 2020, 4:47 pm   #37
ORAWA01
Hexode
 
Join Date: Apr 2011
Location: Stirlingshire, UK.
Posts: 344
Default Re: Marconi C100 B28 vs. Eddystones

Thank you. When I start working on it, will start a new thread for working on the CR100. It has no power lead and 4 x valves are missing just by quick look around it. I am not sure what will need for replacement and what more. Will need your advice and info.
__________________
ORAWA = Old Radios And Wire Antennas
ORAWA01 is offline   Reply With Quote
Old 8th Apr 2020, 4:48 pm   #38
ORAWA01
Hexode
 
Join Date: Apr 2011
Location: Stirlingshire, UK.
Posts: 344
Default Re: Marconi C100 B28 vs. Eddystones

Quote:
Originally Posted by HamishBoxer View Post
I was lucky re my R107,I deposed of it and many years later had a very nice one given to me which I still have.
Re the CR range ,I had CR100 ,CR150 and a CR300 which I believe went to someone on the forum years ago.
My R107 was a topicalised version. It looked battered outside, but when opened inside, everything was like new.
__________________
ORAWA = Old Radios And Wire Antennas
ORAWA01 is offline   Reply With Quote
Old 8th Apr 2020, 5:12 pm   #39
dave walsh
Dekatron
 
Join Date: Jan 2006
Location: Ramsbottom (Nr Bury) Lancs or Bexhill (Nr Hastings) Sussex.
Posts: 4,750
Default Re: Marconi C100 B28 vs. Eddystones

Hi Julian [Re post 29]. Googling DST100DaveWalsh [via the search box on here] brings up threads from around 2012 including info about this set and possible connections with Yorkshire. Did you see those? The chap who was interviewed reminds me of Bletchley and the enduring silence! It was amazing to get further info [even if frustratingly limited] eight years ago now.

I suspect that the R206 Mk1 is almost as rare these days. I don't think you could have spotted mine on your visit to Ramsbottom. [Formerly the Centre of the Unverse but now trendy "New Chorlton"-what a come down for Rammy!] I have a Science Magazine with a 206 featured on the cover, as part of a Weather Station. I once mentioned a description of this set I'd found on-line. It was delivered, from the Station to the owner, in a Post Office three wheel delivery vehicle. A Forum member posted and said "Yes, I wrote that!" but I can't recall who it was now

I've one or two Receivers from the CR Naval Range [including CR100's] and was once attempting to get the whole series. I do have the B29 VLF version. That really puzzled me until I realised it's a TRF set.
[What a Dummy?].

Dave W

[Currently in lock down on the coast-like so many others trying to help themselves and others].

Last edited by dave walsh; 8th Apr 2020 at 5:26 pm.
dave walsh is offline   Reply With Quote
Old 8th Apr 2020, 6:39 pm   #40
HamishBoxer
Dekatron
 
HamishBoxer's Avatar
 
Join Date: Aug 2007
Location: W.Butterwick, near Doncaster UK.
Posts: 7,292
Default Re: Marconi C100 B28 vs. Eddystones

Well the R206 beats the AR88 at 76 KG!
__________________
G8JET BVWS Member and V.M.A.R.S
HamishBoxer is offline   Reply With Quote
Reply

Thread Tools



All times are GMT +1. The time now is 7:43 pm.


All information and advice on this forum is subject to the WARNING AND DISCLAIMER located at https://www.vintage-radio.net/rules.html.
Failure to heed this warning may result in death or serious injury to yourself and/or others.


Powered by vBulletin®
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
Copyright ©2002 - 2020, Paul Stenning.