Bush MB60, TR82, VTR103 and other variants

[Robert G0UHF]

Most will be familiar with the Bush TR82 model, and it was this iconic set that served to rekindle my interest in vintage radio in a big way. For it was in March 2005 that I first became aware of eBay and the large number of vintage radios it has to offer. I immediately came across several TR82's, a set I'd always liked the look of, and of course I now had to have one! All I wanted was to obtain a set in reasonably good condition to put into regular use, but little did I know that initial purchase was to start something of an obsession!

I quickly realised that my blue/green TR82 was not the only colour scheme available, so I now had to have an example of each of the other colours too. Then after reading up on the sets I found out that there was a VHF set to be had, the VTR103, and even an all-valve version, the MB60, which I learned was also the first set in the series. So in a short period I quickly acquired another 4 or 5 sets!

By now I was so interested that I carried out a thorough research of the sets, finding out everything I could about them. This included becoming aware for the first time of the existence of the three rare export models, the EBM60, ETR82 and ETR92, that had MW and 2 x SW bands. Obtaining an example of one of these was to eventually see me winning an eBay auction from a seller in British Columbia, Canada and having the set (ETR82) shipped from half a world away! Such was my enthusiasm at the time for owning all of the variants that during a 4 year period I managed to acquire at least one good example of each of the 15 different variants that I knew of.

Those of you who are BVWS members and so receive the quarterly magazine of the society, The Bulletin, will already know I did an article on this subject in the Winter 2010 issue entitled; 'Variations on a theme - The Bush MB60 family' which went into some detail about all the various models. For the benefit of those who are not BVWS members, and in order to create a sort of reference work for the forum I should like to repeat much of that information in this thread.

The following two tables give the order of release of the sets, type and chassis numbers used, valves and semiconductors types, etc:

   

[Robert G0UHF]

The MB60

Released in 1957 the MB60 is a two band portable designed for AC mains or battery operation, hence the model being designated 'MB' for Mains/Battery. The set is switched over from one power source to the other by the mains lead operating a simple switch arrangement when the plug is inserted or withdrawn from its socket.

The set uses five Mullard Dx96 series battery valves, which was one more than typical four valve designs of the time, due to the circuit having an extra IF amplifier. This made the set a good deal more sensitive, a definite advantage over its rivals. It covers the reception of the long and medium wavebands using an internal ferrite rod with provision to plug in an external aerial via a socket at the rear. The moulded plastic case is light grey in colour with a red rexine band around the middle, brass being used for the 'B U S H' lettering and the trim.

Initially the MB60 was designed to operate using an Ever Ready B147 battery or equivalent, which was a combined HT and LT unit, however the decision was made to modify the original chassis to allow the use of separate HT (Ever Ready B131) and LT (2 x U2 cells) batteries instead. Consequently all MB60's with serial numbers 12001 onwards have the modified chassis arrangement. The chassis remains electrically identical just some of the components, most noticeably the DL96 output valve and some large electrolytic capacitors, have been repositioned to accomodate the different battery types.

                   

[Robert G0UHF]

The TR82

Following on the success of the initial design Bush released in 1959 the TR82, a transistorised version of the MB60. Instead of battery valves this set uses seven Mullard OC-series transistors. Unlike the MB60 the set is battery powered only, using a 9 volt Ever Ready PP9 or equivalent.

The initial models released were the TR82B and the TR82C, the difference only being in the colour scheme offered. The TR82B model has a cream case with a dark brown rexine band around the middle and as with the MB60 the metal trim on the set is brass. Whilst the colour of TR82B case is best described as "coffee" or “mushroom” in shade, Bush described the colour themselves as “Regency Cream”. The TR82C model has a light blue/green case with a dark blue rexine band around the middle, metal trim on these sets being chrome.

           

[Robert G0UHF]

The VTR103

A further development of the MB60 theme came in 1961 with the release of a new set that had VHF coverage from 88 to 100 MC/s in addition to the existing long and medium wave ranges of the earlier models. Given the model designation of VTR103, it had a chassis design that made use of the recently available Mullard AF11x series of alloy-diffusion transistors which offered improved HF performance over the earlier OC-series.

The colour scheme for the set was new too, the case being light cream or ivory in colour with a tan rexine band around the middle. The metal trim is chrome and a telescopic aerial was provided for VHF reception, capped by a translucent red plastic 'pip'. Almost as an after thought, in 1964 the VTR103 design was released in the alternate colour scheme of light blue/green case, blue rexine and chrome trim as per the existing TR82C model and bearing the model designation VTR103C.

               

[Robert G0UHF]

The TR82 modified

Shortly after the VTR103 release, Bush modified the existing chassis used in the TR82 slightly to include an headphone socket. Only the TR82C and apparently not the TR82B received this modification, examples of which all seem to have high serial numbers begining 15xxxx.

In addition this same modified chassis was used for the release of a TR82 set having the same colour scheme as the VTR103, that is light cream case, tan rexine and chrome trim, designated the TR82D.

       

[Robert G0UHF]

The TR82 Mk.II

In 1963 Bush released Mk.II versions of the TR82C and TR82D with a new chassis which also made use of the improved Mullard AF11x series transistors, the existing colour schemes of both models being retained.

Presumably the earlier headphone modification for the TR82C and TR82D was either a way of using up existing stocks of the earlier chassis or used simply as a stop-gap measure until Bush was ready to release the Mk.II models. In any event, it made the sets with the modified chassis relatively short lived and they are fairly scarce in number. Again noticeably a Mk.II version of the TR82B set seems not to have been produced.

       

[Robert G0UHF]

The TR82L

Released in 1964, the 'L' suffix denotes that the set had the addition of a preset '208' tuning button for Radio Luxembourg. As with the standard TR82 models the colour schemes offered were the same. So you could have the TR82CL with a blue/green case and blue rexine or the TR82DL with a light cream case and tan rexine, both models having chrome trim.

But why bother to produce sets with a '208' button in the first place? Well Radio Luxembourg was immensely popular at the time and was the station of choice during this period for the younger generation, however receiving Radio Luxembourg was not without its problems. It suffered a great deal from fading after dark and could be quite difficult to tune in, so a preset button specifically for the station was very useful. No doubt it was a good selling point for the sets.

       

[Robert G0UHF]

The EBM60

The EBM60 was the first export set and as its model number suggests is the export version of the MB60, both models being released at around the same time in 1957. The EBM60 shares the same colour scheme as the MB60 too, that is light grey case, red rexine band and brass trim but the dial is clearly different having short-wave scales and legends.

Interestingly the long strip of brass metal trim at the back of the set doubles as a sort of internal short wave aerial, however a separate plug-in telescopic aerial was also provided with the set which greatly improves reception. Like the MB60 the set uses five Mullard Dx96 series battery valves and is mains or battery powered, using HT (Ever Ready B131) and LT (2 x U2 cells) batteries.

               

[Robert G0UHF]

The ETR82

Now for the most unusual and possibly also the rarest set of the family. Released in 1959 the ETR82 was the second of the export sets and is interesting and unique for a couple of reasons. Firstly it is an hybrid (i.e. valve and transistor) and secondly I believe it is the only hybrid set that Bush ever made.

The circuitry is basically the front end of the EBM60 spliced to a TR82. This was done because the short wave coverage of the ETR82 extended to 18MC/s (16m-band) and the Mullard OC4x series transistors available at the time could not be guaranteed to operate reliably at that high a frequency. Bush got around the problem by using a solitary DK96 valve to perform the task of frequency changer with transistors used throughout the rest of the circuit.

The high voltage supply for the valve was produced from a miniature transistorised inverter (giving around 65 volts in my example) fed from the main 9 volt supply (6 x U2 cells) used for the transistors. The LT for the valve was from another single U2 cell.

Unlike the EBM60, the rear trim was not used as a sort of internal short wave aerial and the ETR82 has a proper built-in telescopic aerial instead of a detachable one which is easily lost. The colour scheme of the set was light blue/green case, dark blue rexine band and chrome metal trim as per the TR82C model.

               

[Robert G0UHF]

The ETR92

The following year in 1960 the final export set was released, the ETR92. By this time transistor technology had improved allowing an all-transistorised set to be produced, the new Mullard OC17x range of transistors taking the place of the frequency changer valve in the ETR82 model. Bush also took the opportunity to extend the upper range of the short wave coverage a little to 22MC/s (13m-band).

Externally the ETR82 and ETR92 appear identical, they share the same colour scheme and both have built-in telescopic aerials. They only vary in the ETR92's dial having been modified slightly to include the increased short wave coverage and with the ETR92 having the addition of an headphone socket.

Battery supply for the ETR92 was 9 volts made up again from 6 x U2 cells instead of the 9 volt PP9 battery used by the domestic sets. Presumably this was done because U2 cells were more readily available than the PP9 overseas.