A great British transmitter to go with the Mosley CM-1

[WQ9E]

I wouldn't mind finding one of these English Mosley Ltd. transmitters to pair with my U.S. Mosley CM-1:

[k4kyv]

But the ad doesn't indicate whether it runs real AM, or that bogus pseudo-AM that is in reality, slopbucket with poor carrier suppression.

[W3GMS]

I wouldn't mind finding one of these English Mosley Ltd. transmitters to pair with my U.S. Mosley CM-1:

Rodger,
That transmitter is very similar in appearance to the famous HBR series of home brew receivers.  It even uses the same Eddystone Dial.  I am in the process of acquiring  the parts to build a later version of the HBR.  An HBR would look great sitting next to that transmitter.  I did fine a brand new in the box Eddystone dial up at the AWA conference this year. 

Joe, W3GMS 

[WQ9E]

Joe,

Great find on an Eddystone dial, they don't show up often anymore and they are quite precious on ebay. 

I have a couple of Eddystone receivers (770U and 830/4) and those are great dial mechanisms.

The second Commando transmitter I find is yours

[WQ9E]

But the ad doesn't indicate whether it runs real AM, or that bogus pseudo-AM that is in reality, slopbucket with poor carrier suppression.

Don,

It is most likely one sideband plus carrier since it is a filter type transmitter.  If I acquire one in the future I will report back with details.  I assume there was also a Commando 1 but I haven't found any information on it and how it differed.

The Mosley CM-1 receiver does a moderately OK job on all modes, it is better with a Q multiplier plugged in.  Mine has what appears to be a factory supplied phono jack on the back for that purpose and I use it with a WRL Q multiplier.    The CM-1 is a single conversion 80 meter receiver (455 IF) with a crystal controlled converter (no RF stage) for the other bands.

Its main claim to fame is the use of only 6AW8A tubes (5 total), probably one of the stranger design constraints used for developing a receiver. 

[KB5MD]

Where might a person find the schematic for the HB receiver?

[Pete, WA2CWA]

I wouldn't mind finding one of these English Mosley Ltd. transmitters to pair with my U.S. Mosley CM-1:

To bad you didn't find this ad a few years sooner. You might have been able to contact the Assistant Manager, G3JOC, for more info. G3JOC now appears on a YL Silent Key list. Don't know when it was added. Doing a Google search, I found some discussion that this transmitter model was sold by the RSGB on ebay a year ago. Never seen any ads/product info/pricing/etc. by the U.S. Mosley so I suspect the product was only destined for International/European sales. Sort of follows in the fabled footprints of the Squires Sanders SS-1T transmitter (i.e. one prototype model cobbled together for  pictures, ads, etc. and then dead).

[WQ9E]

Pete,

Thanks for the information.  I emailed a British friend who has been active many years to see if he has further information about the rig and company.  I will update here if he has anything of interest.

[W3GMS]

Where might a person find the schematic for the HB receiver?

Here is a great website which shows the various versions of HBR's.  Hope that helps you!
Joe, W3GMS

http://www.qsl.net/k5bcq/HBR/hbr.html

Joe,

Great find on an Eddystone dial, they don't show up often anymore and they are quite precious on ebay.  

I have a couple of Eddystone receivers (770U and 830/4) and those are great dial mechanisms.

The second Commando transmitter I find is yours

Rodger,

I would appreciate that!  

Yes, those HBR dials are very tough to find.   I couldn't believe my luck while walking around the Flea Market at the AWA Conference.  Right on the top of the table was a brand new one in it's original box!  I was so shocked to find it, I did not even negotiate the price.  He said $50.00 and I don't think I ever paid for something so quickly!  

73,
Joe, W3GMS        

[vincent]

Eddystone dial:
http://www.ebay.com/itm/Eddystone-898-Slow-Motion-Drive-/110741241915?pt=UK_ConsumerElectronics_SpecialistRadioEquipment_SM&hash=item19c8b1403b

radiohamjohn
this gentleman seller have a lot of interesting RF components at interesting prices

Hi Pete (WA2CWA),
about the Squires-Sanders (what else?) SS-1T; have you ever seen a picture of this prototype transmitter?
Regards

[vincent]

An intersting site for Eddystone Dials and HBR 13C receiver:

http://www3.telus.net/radiomuseum/projects/HBR13C/HBR13CUse898Drive.pdf

BTW the two Eddystone 898 dial pictures are mine, the site owner has "gently borrowed" these pictures from my listing on eBay some time ago. I had ten of 898 dials.

[Todd, KA1KAQ]

Clegg used the Eddystone dials to great success with the Zeus, Interceptor, and Venus. Have seen a number of HBRs with them as well. That Jackson Bros drive is the bees knees.

Rodger, please post whatever you find here. That's another of those curious transmitters that, even if you never see or own one, would be great to learn more about.

[The Slab Bacon]

I wonder if it used all 6AW8s like the receiver? ?    

[WQ9E]

I wonder if it used all 6AW8s like the receiver? ?    

Perhaps a proper Mullard "valve" instead  

The Galaxy 2000 linear amplifier with its 10 6HF5 tubes in parallel was reviewed in another issue of the RSGB bulletin (the same source as the Mosley advertisement) and was generally well received.  They were less impressed with the Heathkit HA-14 "compact kilowatt" which arrived for review in assembled form with exposed HV wire at the connector ends.

A Star receiver (maybe early Yaesu) is featured prominently in a number of advertisements.   In the Heathkit ad appears a RA-1 "basic amateur" receiver.  It is the UK version of a HR-10 and looks very similar.  I have one and it is a bit better than ours since it covers 160 and also provides a slow speed tuning mechanism.  This was also available as the RG-1 general coverage and I don't believe Heathkit sold a similar model over here.

[G3UUR]

Rodger,

It looks like you’ve picked up a bunch of RSGB Bulletins from the ‘60s. They make interesting reading, particularly the series on receiver design by G2DAF.

The Mosely Commando SSB transmitter was produced here in Norwich, not far from where I’m currently living. O J (Jack) Russell, G3BHJ, was manager of Mosely UK back then. Owen Chilvers, G3JOC, took over as manager in about 1964 or ’65. He was the Assistant Manager for a while before that. They produced the Commando from about ’63 through to the end of ’65. I’m pretty sure that Don, G3JIE, had something to do with it in the early days, so I’ll see what he can remember about the design. I’m also pretty sure that my old friend Roy, G3ZIG, has one in his collection. I’ll check with him and see if he’s got any photos of the internal construction that I could post on here for you. I have only ever seen 2 Mosely Commandos in many years of collecting vintage equipment. They’re pretty rare here in the UK, so I don’t think many were made.

I can’t agree with you about the RA-1 being the UK version of the HR-10. They are quite different in design, although the American and British designers had similar briefs for the specifications of their respective receivers. Looking at the front panel, the only similarities apart from their colour schemes are the slide-rule type dials. Otherwise, the control locations are totally different and the ‘S’ meter is on the opposite side of the dial in the two receivers. Looking inside, the chassis layouts are quite different and the tube line-ups are totally different. Having spoken to the guy who designed both the RA-1 and the RG-1, I know for a fact that the RA-1 is not a copy of the HR-10. He was allowed to meet the design specification his own way and chose to use a special version of the Electroniques QOILPAX for the front-end. 

There are clues as to whether a British Heathkit is a re-engineered American Heathkit design. You just have to look at the model number, and if it has a ‘U’ at the end it’s a copy re-engineered to use British components. Models such as the RA-1, RG-1, RSW-1 and MA-12 were independently designed in Gloucester for Daystrom (Heathkit) Ltd and only available in Europe. There were some hi-fi items that were independently designed for the UK market as well.

In case you’re wondering about Electroniques, they were the UK equivalent of J W Miller and produced IF transformers and coils in the main. They also came out with a ready made front-end called the QOILPAX that was available in ham band and general coverage versions. They were taken over by STC (ITT) in about 1966 and went downhill from then on. Ron Wilson, G4RW, who was the founder of Electroniques, bought back the name and remaining stock when STC closed the company down. He died a few years back and John, G3XIX, who is radiohamjohn on eBay, started selling off the remaining stock. As Vincent said, he has some useful RF bits and pieces on offer. A lot of the really good stuff has already gone, unfortunately.

Dave. 

[vincent]

Reading the interesting information posted by Dave brought me to mind the excellent hybrid receiver designed by G3PDM, Peter G. Martin. A 1.62MHz IF single conversion design, 7360 balanced mixer fed by a low phase noise PLL tube/valve local oscillator and noise blanking. Super! It used Electroniques coils and Eddystone 898 dial. The design appeared in the Radio Communication Handbook (fifth edition) and (if I am not wrong) in some late sixties RSGB bulletins.

[WQ9E]

Dave,

Thanks for the information!  The RSGB bulletins are very interesting reading and I have the years 1962-1967.  I have only recently started going through them.  I also acquired a couple of the RSGB handbooks which seem to be  more in the technical style of the Orr/West Coast handbooks than the ARRL publications.

Also thank you for the information about the RA-1, after I got it my HR-10B is sitting on a high shelf and the RA-1 is paired with my DX-60.  It is a very usable receiver and a lot of novices would have been happier if the UK basic receiver had been sold over here.  The addition of the fine tune mechanism is very useful for CW.  I expect the general coverage RG-1 was also superior to what Heathkit was selling in the U.S. in the line of  lower cost (less than SB-310) shortwave receivers and would have been a welcome addition to the lineup.

Do you know if Electroniques was the manufacturer for the pre-assembled front end used for the RX-1 Mohawk?

[G3UUR]

Rodger,

It's funny that you like the RSGB Handbook and I prefer the West Coast one. It must be a case of the grass is always greener ..... I didn't see a copy of the RSGB one until some time in the '70s. I lived near two USAF bases (Lakenheath and Mildenhall) when I was growing up and a Master Sgt stationed at one of them gave me a copy of the 15th Edition of the Radio Handbook as a present in about 1965. That was the only handbook I had for quite a few years and I still have it - plus quite a few others from the same stable.

I contacted John, G3XIX, about the pre-assembled coil pack for the RX-1. He used to work for Electroniques and knows pretty much all there is to know about what they made and for whom. He says they made none for the American Heath Company. They just supplied coils for the GC-1U Mk II and Qoilpax for the RA-1 and RG-1.

Vincent, the G3PDM receiver was a good design but didn't really catch on with UK amateurs. Many amateurs who wanted top-notch performance built the G2DAF designs and others who didn't feel confident enough to tackle such a large project went for projects like the G3RKK receiver which used a Qoilpax front-end. Electroniques made coils and IF transformers for all the magazine designs back then. They offered a tremendous service to constructors and were really helpful to novice builders like myself. My first superhet, which I built in 1964, used Electroniques coils and IF transformers. The dial was an SMD-2, which used one of the dual-ratio 6/1 and 36/1 epicyclic drives that radiohamjohn is currently selling on eBay. I bought one of those off John to use in a replica of my original SimpleX Super receiver, which I intend to build when I get the time. It's a very simple receiver but gave me a great deal of fun on 40m and the new version with improved crystal filter should be even better.

Dave.   
   

[vincent]

Hi Dave,
Thanks for your interesting information. I believe that the G3PDM receiver was an uncommon (but interesting) design, (7360 mixer, tube PLL LO!, noise blanking etc.) maybe, that the reason why it had no great success. Ingenious is the band changing (just moving the Preselector knob from one side to the other), between the 80M and the 40M, of the Simplex receiver. The Electroniques inductors and transformers are of excellent quality and variety. I am a very fond customer of radiohamjohn (John) with whom I exchanged, some time ago, a few pleasant emails.
Regards.
Vincent.

[G3UUR]

Hi Vincent,

I think the G3PDM design didn't catch on because it was late on the scene, the circuitry was slightly unusual, and the 1.6Mhz crystals were expensive compared with a mechanical filter. Yes, the Electroniques wound components are very good and I've stocked up on them while they're available. I've probably been a bit greedy, but you have to get this stuff while you can.

Rodger, one or two amateurs have improved the RA-1 for CW by adding a second half-lattice section at IF B and installing a diode product detector. I don't have any closely spaced 1.62MHz crystals for CW, but do have a spare pair of 1.6202/1.6184MHz crystals if you want them. They'll improve the skirt selectivity quite a bit.

Also, if you're serious about getting hold of a Mosely Commando, there may be one available shortly in North Wales.

Dave.