VPR5 Text

This is a discussion (well more of a rambling essay actually) about a remarkable example of late
20th century technology, by Gino Mancini.

(Click on any of the thumbnail images below to get larger versions and further comments. This
text was last revised in May 2005.)

INTRODUCTION

I can still recall a certain slackness in my jaw as I first came across a picture of the VPR-5 in
Nagra's Audio & Video product line catalogue of June 1988. I had been well bitten by the video
equipment bug by then, and together with a good like-minded friend had already travelled to
various far-flung corners of the UK in search of old (and thus very cheap) bits of video kit. I
particularly remember enjoying a few glasses of good Port in quite a posh hotel in York while
they closed the bar around us, having filled a van with ageing IVC equipment earlier in the day.
Later I was quite glad they had grab rails along the corridor to our rooms, but I digress...

That Nagra catalogue rather changed my aspirational goalposts, and my mind wanders back to an
even earlier time in the mid 1960's when having proudly just spent 30 shillings on a new stereo
pickup cartridge (that's 1.50 in UK Pounds, and yes I am that old), I found out that an outfit called
Ortofon made pickup cartridges at over ten times that, and you needed a special 9 quid
transformer just to be able use it.

So one learns that everything is relative, and It's a bit like that with this little Nagra video
recorder, for when Kuldelski were building them you could get a very respectable domestic
portable video setup for say Ł1,000, or you could re-mortgage your house (and sell the family) to
get a VPR-5 for over thirty times that, and you still needed a camera and lens of matching quality
at perhaps another twenty five thousand quid. Better sell the Porsche (and the BMW)...

Actually I didn't know when I was staring with lust at all those unattainable toys in Nagra's 1988
catalogue, that in fact their stunning miniature video recorder was already quite obsolete by then,
and had been replaced by something much more convenient, of slightly lower quality and of vastly
lower romance; Sony Betacam (but there again I don't get out much).

It's a bit like reel-to-reel and Compact Cassettes (remember those?) Valves verses Transistors
and Betamax verses the dreaded VHS, all nearly forgotten now. And so perhaps with the long
monologue that follows I am fighting (well perhaps just bleating) a sort of minor rear guard action
for yet another nice bit of discarded technology. Perhaps as might a steam railway enthusiast have
done thirty years ago when the nice Dr Beeching closed all those branch lines and brought in the
Diesel-Electrics. Well I am a person of a certain age...

If you already know what a Nagra VPR-5 is, you won't need an amateur like me to tell you how
nice it was, if you don't but you do like old or interesting technology I hope you find what follows
to your taste. Sorry about the writing style but I'm no technical author and the whole thing started
out as a sort of personal user-manual almost before the Internet was invented (and I can't face a
complete re-write). I have though tried to include some nice pictures of the machine and other
items mentioned as I go along.

Fade up from black to perhaps six years later, times change and the BBC has moved on from
reel-to-reel video recording on 1-Inch tape, and after quite a few telephone conversations,
some racking of brains and a much lighter wallet, one of their Nagra VPR-5s is mine, all
MINE!!

Ahem...

In 1994 I acquired an Ampex/Nagra VPR-5 portable 1 Inch C Format video recorder. I had
been aware of this interesting machine for some time, though for obvious financial reasons it
was to be a good few years before I was able to get my hands on the example you mostly see on
these pages.

Since childhood I have been attracted to technical things and in later life collected various bits
of unwanted old technology that included a few items of broadcast television equipment. Hi-Fi
was also a consuming interest once, and while it seemed difficult enough to reproduce an audio
frequency response of say 20 to 20 kHz with a good degree of 'fidelity', to do the same with a
video bandwidth some 250 times wider seemed a very interesting proposition. Indeed because
of the many technical challenges involved, broadcast television equipment was until recently
forced to embrace many truly state-of-the-art engineering values. Though happily for the
impecunious collector such as myself, the relentless changes in technology and format provided
a happy hunting ground for the many interesting and often beautifully made things that were
mostly just thrown away. It then became just a simple race between the land-fill site or one's
own private 'museum' (and later perhaps back to the land fill site anyway).

And so for perhaps a 50th of what that little silver machine probably cost the BBC my VPR-5
became a valued item in a modest collection of other obsolete 'junk'. And over the decade that I
have enjoyed this complex and glittering little box I have tried to learn about the machine's
background and about the circumstances that brought it about. Unfortunately though with rather
limited success so far, as while some technical documentation remains, virtually nothing seems
extant regarding how or why this rather unique video recorder came into being in the first
place. Michael Mailes's comments seems to suggests that Ampex refined an already built Nagra
prototype, but what caused Kudeleski to make such an extraordinary machine in the first place?
We know that the Nagra SNN was built originally to record White House conversations (as
stated elesware on the Web), and that they built other specialized surveillance recorders for the
Americans as well as the Russians. Nagra also made all sorts of advanced instrumentation
recorders as well, some of which one might find lurking inside a prototype missile or torpedo.
Could therefore the VPR-5 have started out as part of some airborne military or scientific
instrument package, that was later developed for broadcast TV use with the help of Ampex? Or
did Nagra perhaps bite off more than they could chew and have to get Ampex to help them iron
out the bugs? It is interesting to speculate how such a lavishly engineered and (outrageously?)
costly device seemingly rather suddenly came on to the broadcast television market in the early
1980's. But if it was indeed a by product of the cold war we may never know the full story.
However as this machine does seem to be so unusual, I thought it would be worth shareing what
little I have found out about it.

I think it is fair to say that the Ampex/Nagra VPR-5 is regarded by those 'in the know' as
something of a minor legend in it's own lifetime. During my research, a number of people I
discussed the machine with knew of the existence of this little Swiss wonder though many had
never actually seen one. One professional owner and user said (and this had already been
demonstrated by Mr Mailes) that it was so tough that you could stand on it without causing it
harm, which is quite true provided that the cover was locked-on. Though the reason why one
would want to be able to do this might be open to conjecture. There was also a consensus that the
VPR-5 recorded the best quality pictures of all the Ampex C Format video recorders. This was
no small achievement considering it's minuscule size in comparison to studio and the other so-
called portable 1-Inch machines. A respected ex-BBC sound recordist while highly praising the
Nagra's sophistication, did however make remarks to the effect that the machine could be rather
tricky and unpredictable to work with, because 'you never knew what it was actually doing Gino'.
Such are the differing perceptions between the knowledgeable professional user and the
enthusiastic amateur collector. His opinion I well respect, and while the BBC also deemed it
necessary to make one or two minor 'improvements' I am still though inclined to conclude that this
little recorder is one of the finest examples of late 20th Century electromechanical engineering to
be found anaywhere. It is an object lesson in how form can follow function and not just mere
fashion, it's not perfect of course but does certainly have a high 'wow factor'.

There are now doubt good if not better examples of this sort of uncompromising 'glittering
engineering' to be found in things space or military. But the writer knows of no other real world
piece of kit that directly compares to this complex little silver box. Of course there are other
Nagra devices that are not too far off the mark, and I am thinking here in particular of their full-
sized T-Audio tape recorder, or perhaps at the other end of the scale the tiny and watch-like SN
series of machines.

Described as a third generation C Format video recorder by William F. Carpenter's of Ampex, in
his article published in the September 1983 issue of the S.M.P.T.E. Journal. The VPR-5 was
probably engineered in the early 1980's by Kudelski S.A. of Switzerland and was refined by
Ampex Corp. of America. These two companies were in their different ways THE most respected
and experienced manufacturers of magnetic tape recording equipment. Ampex was at that time
arguably the world leader in magnetic recording technology. They had after all developed audio
tape recording from the captured war time German AEG Magnetophon equipment and had gone on
to invent the Quadruplex television recorder, which was of course the first successful video tape
format. Later Ampex would develop (though did not invent) far cheaper and more compact 1-Inch,
Omega-wrap helical-scan machines which would become known afterwards as the A Format.
These machines became widely used in industrial and the then rather fashionable educational-TV
environment. Ampex also produced the rather epic TM-7 self-lacing computer tape drives that
became so popular as props in old science fiction films of the 1960's and 70's. Ampex also made
high technology 'Winchester' disk drives, as well as fiendish ferrite-core computer memory
plains. American technology and 'know how' ruled, but this was a while ago when computers
were real computers and men were real men etc, etc.

In those days Kudelski was by contrast a much smaller Swiss company that produced the famous
and highly regarded Nagra range of portable audio tape recorders. These rather unique looking
machines were without parallel for quality-of-build, performance and reliability (the late version
Stellavox recorders possibly excepted). Highly expensive, remarkably well engineered, but no
'nonsense', the Nagra (which means 'it will record' in Polish!), was for many years 'the' standard
portable audio recorder as used by the film industry. As Francis Rumsey wrote in the November
1991 issue of Studio Sound:

' The Nagra 1/4 inch tape recorder has held its place firmly in the film industry as the machine of
choice for portable high quality work in the most inhospitable conditions. This analog recorder
has a reputation for reliability and solidity inspiring confidence in the film recordist for a number
of years, although the weight of all this solidity has affected many a shoulder.'

In the late 1970's the co-developed Ampex / Sony 1-Inch C Format was becoming the de-facto
broadcast videotape standard. While the media and the equipment was more compact and had a
much lower cost of ownership than the older 2 inch Quadruplex system, the newer C Format
machines still remained much too bulky for portable use. Ampex, Sony and Hitachi had already
produced a few what might be described as transportable C Format recorders. But in reality one
could hardly carry any of these bulky machines with ease or comfort, as they all weighed around
20kg and were the size of large suitcases. Bosch in Europe had developed what became known as
the 'B' 1-Inch format slightly before Ampex's C system. This was a sort of cross between
Quadruplex segmental recording and the single field 'slices' of Helical Scan. They seemed to have
taken a Quadruplex head wheel, removed 3 of the video heads and mounted it horizontally in the
transport, then wrapping the tape around this 'scanner' in an 'alpha wrap' rather like IVC used to
do. The end result was a rather more compact transport that was said to produce better quality
pictures than the Ampex system. But because the B Format still made a segmental recording the
TV picture had to be 'assembled' electronically back together again, and therefore was not much
of an advantage over Quadruplex for editing or slow motion playback. B Format did though have
an advantage for portable use because the much smaller head drum allowed very compact and
light-weight recorders (in reel-to-reel and even cassette form), that were much 'handier' than any
of the big C machines. Unfortunately the B Format while becoming popular in Europe did not
compete successfully in the all important American market, because perhaps it wasn't invented
there. This forced many broadcasters in the States to employ inferior quality though quite portable
High-Band versions of Sony's U-Matic cassette system (though this was also not invented there)
for electronic news gathering or electronic field production. However, it is well known that
American broadcasters would and did use almost anything for news gathering, even VHS. It
would have therefore seemed highly logical in the early 1980's, for the two major players in the
professional video and portable audio recording business to team up and built a truly portable,
truly broadcast video recorder, and so they did...

While wishing to learn more (do please do help if you know the full story) how this transatlantic

collaboration came about and how things went during the gestation of this complex project, I now
know that Ampex acted as consultants for video circuit refinement and that Kuldelski designed the
mechanics, built and assembled the machine. Certainly there is nothing inside the recorder to
indicate a source of manufacture other than Nagra, although one would expect items such as the
video head tips would have been sourced from Ampex or their sub-contractors. (VPR-5 video
heads are not interchangeable with Ampex equipment) As the writer has had some years
peripheral experience with medical electronics product development, it is a wonder to him that
this complicated creation actually got to see the light of day at all. Not surprising then that it was
introduced into the marketplace too late, and remarkable that it actually worked as well as it did.
(Though one does have this nagging suspicion that the machine may have started out for use in a
somewhat more exotic environment than the broadcast television industry...)

Ampex Corp. were to market and service the machine outside Switzerland. The term 'badge
engineering' comes to mind, though perhaps a little unfairly. But Ampex's part numbering system
for spares and accessories was to take precedence. Quite sensible perhaps considering the
American company's market reputation and highly established customer base. The VPR-5 was
though quite unlike any other Ampex product and indeed was quite unlike any other video or audio
tape recorder. Lacking the usual vacuum-formed or moulded plastic casework, this machine was
somewhat 'Swiss' in looks; lots of glittering silver-anodized machined alloy with an apparent
manufacturing philosophy of 'let's not use plastic when we can CNC machine everything from
solid chunks of aerospace alloy'. But as we will perhaps see, there were probably some perfectly
valid reasons for this uncompromising approach.

The VPR-5 was introduced to television professionals at the 1982 International Broadcasting
Convention at Brighton on the South Coast of England (of all places). But series production did not
start until April of 1984. One wonders how the machine was received by its prospective customers
apart from shock at the cost perhaps. Also by 1984 it was getting rather late in the life of the C
Format, and was at a time when various 1/2 inch cassette-based 'tuned-up' domestic camcorder
systems were starting to appear. Indeed the all conquering Sony Betacam format had already been
shown to the industry in its first incarnation some 18 months before the announcement of VPR-5,
and naturally these new cassette / component based video formats would have a significant
negative impact on the success of the Nagra. In addition, the VPR-5's considerable cost even in
comparison to other portable 1-Inch machines did no doubt limit its use for anything other than very
top end broadcast E.N.G. or E.F.P. Surprisingly though a few corporate and industrial video
producers also bought them. And even the odd 'pop star' was known to use VPR-5's while 'hanging
out of helicopters and climbing mountains'. (Actually, a VPR-5 and Ikegami HL79d camera were
rather lighter than an equivalent all-in-one Betacam 'camcorder' of those days - but the cameramen
did not like being tied by a length of cable to the recorder's operator though.)

The publicity 'litrature' for the introduction of the machine displayed a fairly depressing lack of
imagination. The S.M.P.T.E. Journal copy and the first leaflet shows the usual pretty girl with a
camera on one shoulder and the recorder draped over the other, just like it was some cheap
amateur portable 'video' of the time. If one is charitable one might suppose that they wished to
draw parallels with the convenience (such as it was then) of contemporary domestic equipment.
But to the writer this approach just looks weak. Later they used un-captioned drawn images of
planes, cameramen and operators, and even a 'cartoon' of an harassed jungle explorer carrying his
VPR-5 while being pursued by irate spear throwing natives (!). This half-hearted rather muted
approach in retrospect suggests that Ampex were a little ambivalent towards 'their' superb though
alien product. They probably did appreciate the quite remarkable intellectual design and
manufacturing achievement that this little box represented, trouble was it wasn't actually theirs (but
there again neither were any of 'their' cameras).

The VPR-5 together with the preceding Ampex VPR-20, the Sony BVH500, and a surprisingly
sophisticated device produced (but possibly never sold in the UK) by Hitachi, seem to have
been the only C Format portables ever made. They appeared perhaps between 1978 and 1984,
but Nagra' machine was by a very large margin the smallest and lightest of them all. It was also
the last portable C Format recorder introduced and was probably the most sophisticated, having
in addition to its remarkably 'llipution' proportions a number of highly advanced operational
features. Some of these in fact proved to be many years ahead of their time, and included an
'intelligent' power management system, extensive onboard self-diagnostics, and an elaborate
automatic audio level control. But despite its small size, light weight and advanced features, it
really was too late and (much) too expensive.

That it is of course no matter at this distance now that video recording itself has become just to
do with the manipulation and storage of digital bits. To those who appreciate 'old fashioned'
engineering values it is likely that we will not see the like of these machines again. The passing
of professional reel-to- reel recorders (both for video and for audio), together with other now
historical objects such as the mechanical chronometer and the precision 35 mm still-camera,
mean that objects such as these will probably become the last monuments to the aesthetic and art
of proper engineering; artefacts of a lost mechanical age. It is ironic that the new popular fashion
for 'silver' home technology is in reality just the cheapest sprayed moulded plastic and folded
tin, while the likes of Nagra's obsolete machines described here are quite simply the real thing. I
suppose it is a by product of middle age that one becomes rather tired of constantly being told
that what is new is better. As they used to say in London when I was young - do me a favour!

The prevailing conditions some 20 years ago must also have been rather depressing for Ampex
and Nagra, as Sony were finding that their new Betacam camcorders, which were originally
aimed at the rather poorer industrial users, were in fact rapidly gaining favour with serious
broadcasters. Indeed this much more convenient though of slightly lower quality (SP version
included) system, was to have a very significant impact on the long term American manufacture
of broadcast television equipment in general. The technological high ground in broadcast video
was, as with so many other things, being taken by those from the other side of the World. One
may imagine that the vast amount of domestic product churned out from the Far East was and
continues to finance lavish R&D into ever new generations of professional video stuff. Though
for most everyone else this sort of funding could not be generated from the limited niche markets
that many a western manufacturer was forced (by stock market enforced short-termism mostly)
to retreat into. I suspect that inept management also had a significant part to play as well - but
what's new eh?

The various features of the VPR-5 summarised as follows:

This type of machine is known as a direct colour recovery video recorder, and it records the
whole bandwidth of a composite video signal onto the tape without the compromise of any form
of hetrodyne colour-under (or digital for that matter) signal processing. When fitted with its
standard cover and in its normal padded working bag, the VPR-5 could record for a nominal 20
minutes. The Ampex helical 196 magnetic tape it used, came wound on small and rather donut
like plastic reels which were unique to the machine. These were supplied in either single or
double cardboard boxes. Standard 1 Hour reels of 196 tape could also be fitted, though this
required the machine's reel hubs to be rotated and locked into their outer positions. An optional
weather-proof large 'Mickey Mouse' reel cover could also be fitted, but this was not needed if
you were working inside and on a table perhaps. The small 20 minute VPR-5 reels could quite
happily be accomodated for playback by both the VPR-80 and VPR-6 studio recorders (and I
also expect by the VPR-3 as well).

The VPR-5's (PAL) frequency response was quoted as 'flat to 5Mhz', which in contrast to other
analogue formats such as VHS, S-VHS, 8mm, Hi8, and U-Matic, gave a recorded resolution of at
least 600 horizontal lines. The downside of the 1-Inch format was that you needed a direct colour
recovery time base corrector (TBC) to get stable and 'broadcastable', pictures from the tape
deck. At this cost level though it was normal for individual studio play back machines to be
equipped with their own TBCs. (TBCs were once very costly and elaborate items. These days
they suposedly can put them on a single chip.)

The VPR-5 has both video and audio 'confidence playback' (real time off-tape monitoring of the
recorded signal). This is in monochrome though, and is for use with an attached camera's B&W
viewfinder to inform the cameraman that nothing 'nasty' is going on with the recording. A seperate
colour adapter with comprehensive powering and nice internal battery charging facilities was
available for playback in-the-field. This adapter was no replacement for a 'proper' time base
corrector though, and only provides colour-under type performance (which equals about 250 line
resolution with no drop-out compensation). The VPR-5 could of course be used with a studio
TBC such as a TBC-6, and is equipped with advanced sync inputs and an off-tape RF output for
dropout compensation. But, it was not made to be a broadcast palyback machine and its replay
electronics do not have the performance of a 'full sized' studio machine.

The VPR-5 has a very comprehensive linear time code generator and reader, that can be
referenced to external generators or to other similarly equipped recorders. This alows for multi-
machine synchronized recording of a live event. The linear time code track is fitted in place of
one of the 4 pre-wired audio channels (usually channel 4). Continuous or sequential time code
recording is available. The machine's internal reader displays hours, minutes, seconds and frames
on the right hand L.C.D. The machine also has a 'normal' digital tape counter driven from an
optical encoder built into the takeup tension roller. (These articulated tension rollers can also
pivot vertically by about 5 degrees.)

Because this is a portable and self-contained machine, the powering system is very flexible and
also has some 'intelligence'. All internal power supplies are of an advanced switched-mode type
and the CPU insures that only relevant circuitry is powered up for each specific operating mode.
The 4 DC electronically-comutated motors (Hall-effect sensing; no brushes to wear out) have their
own individual highly efficient switched-mode powering systems.

The fast-charge NiCad battery system seems to have been at least 10 years ahead of its time. Two
types of battery pack can quickly be attached or disengaged from the rear of the machine, and
contain circuitry that provides data to the recorder's CPU on cell temperature, battery past
discharge performance, current level of charge and previous run time. This means that the machine
can calculate an accurate estimate of battery run-time left for any battery pack attached in
whatever state of charge and in any mode of use. This information I have found to be accurate to
the minute, and is displayed on the right hand LCD.

The separate charging systems consisted of a 6 battery pack slowish charger and a 2 battery pack
fast charger. These use the battery's in-built cell temperature sensors to prevent overheating when
on charge. If running from the mains PSU the recorder's in-built 'toping up' charger also updates
the battery's state of charge data and increments the estimated run-time. An accurate estimate of
tape remaining time is also available to the operator. This is calculated from take-up and supply
reel rotational data when transporting tape, and has proved also accurate to the minute. When in
fast wind mode, the machine automatically slows the tape down on nearing the end of the reel to
avoid damaging the tape or the video heads as it comes off the spool. All not too bad for 20 plus
year old technology?

The syscon CPU (1 MHz clock) performs a number of on-going house keeping tasks: checking
general 'health' parameters, calculating battery remaining time, tape remaining time, and powering
subsystems in the configuration relevant to the operating mode selected. The whole machine is
very consistent in its actions and handling of tape, and is also extremely reactive to user
commands. The various watchdog and self-diagnostics help to ensure the continuing 'good health'
of the recorder. If any out-of-range conditions occur the CPU. will safely shut that section of the
machine down and display an applicable error code on one of the LCD's. This is intended to
prevent any inclination to self-destruction. In addition, a knowledgeable user may access a fairly
wide range of user defined options and self-diagnostic modes. The numeric key pad and the LCDs
may be used as a simple 'terminal' to communicate directly with the syscon and time code

CPUs. The user may select various day-to-day functions, such as setting time code user-bits or the
various display modes, or can delve much deeper into the machine's operating system. By keying
in various coded instructions, most subsystems may be individually evaluated for their current
state of health. Therefore a knowledgeable user may quickly ascertain his VPR-5's overall
condition, including (with the 'Mk2 version) the machine's power on time and the video head
running time. However information is lost if the Lithium backup cells go flat, and despite all this
cleverness I know of one case of near total self-destruction when a machine caught fire internally.
This underlines the sobering fact that (even Nagra) high current switch-mode power supplies and
DC motor drivers can sometimes 'let go' in dramatic ways.

To minimize weight 'Aerospace design and machining techniques' were used. This is not mere
advertising hype, as the VPR-5 shows mechanical design and fabrication philosophies that are to
be found in any item of state-of-the-art avionic or space exploration equipment of the time. To
save weight, most of the machine's mass - perhaps over 90% in some places, was meticulously
C.N.C. machined away. The resulting high strength lightweight components were then assembled
with considerable skill and ingenuity. Fortunately all this effort was eventually recognized by the
industry, as Ampex applied for and was granted an 'Emmy' for their (and Nagra's) work of art.

Why to the writer all this fine precision and machined alloy seems so satisfying and pleasing to
the eye is not known. Another aspect of attraction is perhaps that open reel tape machines perform
their business in public, and one wonders if the rotation of the reels and the movement of tape
might perhaps cause subtle positive psychological effects. At any rate, in contrast to 'inanimate'
machines where the business of recording is performed 'secretly', all reel-to-reel equipment has a
certain life and presence when 'doing its thing'. And this is especially true of the VPR-5 when that
big 5 Inch head drum spins up to its 3,000 rpm running speed, taking 1 second and some 16 Amps
from the battery to do so.

Enough of the metaphysics though. This machine was carved from solid metal for entirely
pragmatic reasons, because (of course) the chosen raw material for its structure dictated this
particular way of working. The aluminium alloy used is the increasingly well known 'aerospace
grade' type 7075-T6. This artificially aged material approaches the tensile strength of steel and is
unaffected by cold working (machining), it cost though about 4 times the price of less exotic
aluminium alloys. It is also quite unsuitable for casting or welding, but again, no cast light-alloy
structure could approach the strength of a machined-from-solid anealed plate of the stuff. Where
joins had to be made they used stainless steel screws, rivets, or a very nice metal-loaded epoxy
glue. Machined 7075, rivets and nice glue was by the way what the Saturn 5 'Apollo Moon
Rocket' boosters, and probably many ICBMs were mostly made out of.

All the internal and external surfaces of this machine are anodized to protect against corrosion
and to increase strength. Though how they got that perfect graining in all those various hidden
recesses is a mystery. This is probably a by product of the anodising process that highlights the
grain of the metal. All ledgending is in anodic print, so it won't wear off. One could believe that
this machine was the very height of what is known in management speak as 'best practice', though
the extremes that Nagra went to in some instances does seem rather too much of an overkill
sometimes.

Take for example the audio and video interface modules. These light weight little boxes that lock
so easily into their respective locations on each side of the machine have cases that seem to be
machined from solid blocks of alloy. Indeed it seems that perhaps 90% of material has been
removed to leave just the thin outer skin and some narrow mounting flanges. Could these not have
been cast in aluminium, or even moulded in a suitable plastic? Perhaps Nagra got a good deal on
all that swarf. They do seem quite tough and look very nice though...

The front panel is also machined from the solid, and possibly represents less than 20% of the
original material present. In fact the inside surface of this panel is a more complex milled surface
than the outside. Each control button is a solid CNC carved and colour-anodized component
retained in position by an individual leaf return-spring. To help prevent accidental damage and
inadvertent operation, the controls and buttons are all well recessed into the front panel. The
heads of many of the exterior fixing screws are fitted with small Nitrile O rings, presumably for
retention as well as water proofing.

The locking lid assembly seems to be a rather complicated paradox. The top surface is another
machined-from-the-solid alloy plate with three O ring-sealed polycarbonate (?) viewing
windows. Underneath this lid are undercut girder-like strengthening features ('intrgrally machined
T stifners'). The lid contains a marvellous over-center cable locking system, operated by a
beautifully milled recessed stainless steel and alloy folding handle. (I counted over 150 separate
components in this lid.) The top plate is bonded to the riveted thin-alloy side walls with a metal-
loaded epoxy resin, and the whole thing locks down and seals to the recorder's deck plate with 5
individual spring-loaded latches. A quite remarkable structure, probably proof against the
elements, and you can stand on it (as Mr. Willetts has demonstrated). But would not a transparent
vacuum-formed plastic cover as used on their audio machines have been a rather more sensible
approach? Well apprently not for heat sinking reasons I am advised, though how you get inside
this wonderful lid if that complex locking system should fail looks an interesting challenge. Ah,
but (of course) there is a proceedure for doing this described in one of the manuals.

By carefully releasing the 7 O ring-sealed screws retaining the top plate of the recorder, you are
able to lift the transport and the whole upper surface of the machine upwards on two small
hinges. This surface is made up of two separate machined plates one within the other; the inner
tape transport chassis itself and the surrounding top cover of the electronic package, there is a
small gap between them. The transport chassis is supported within the surrounding cover plate
by 3 strategically placed short stainless steel pins. This I imagine defines the external stresses
placed on this critical component. The top cover is sealed onto the rest of the machine by a large
elastomer O ring. Surprisingly few mechanical components project below the lower surface of
the transport. The scanner, capstan and reel motors are either situated within the deck assembly
itself, or are built into their own respective areas above the transport. Normally reel and
scanner motors are quite bulky items especially on 1 Inch tape machines. But in this recorder the
reel motors together with their reduction drives and parking brakes are actually built inside the
NAB-type reel hubs (US patent 4,542,663 filed Sept 15 1983). What makes this all the more
impressive is that despite their minimal volume, these complex 'powered hubs' have no trouble
at all in driving the big and quite massive 9 Inch, 1 hour reels at high speeds. The reel motor
commutation and drive electronics are built into the machine's substantial base plate.

Also provided within the machine, (as with most Nagra products) is a small plastic tube of
basic spare parts. How thoughtful. The whole of the interior of the VPR-5 is virtually filled with
multi-layer surface-mount printed circuit boards, together with a miniature wiring loom. The
electronics are in roughly four layers;

1) Fixed under the transport (audio and video record and replay).

2) Above the middle central dividing plate (audio AGC, time code, system control).

3) Below the central plate (reel, capstan and scanner digital servos).

4) Built into the upper surface of the base plate (PSU, bus, reel, capstan and scanner
commutation).

There are 17 main circuit boards and another 20 smaller sub-boards, and all of these are
interconnected by means of a very nicely done avionics style wiring loom which employs a
mixture of flat miniature 'headers' and hand-soldered lay-on joints. The loom's connections
number over 1,000, and each of the 500 wires is marked at both ends with various references
and even the volts carried. There are over 435 transistors and 285 surface-mount I.C.s in this
beast, together with a further circuit board and 15 I.C.s in each battery pack.

The main electronics package is divided horizontally by a milled and anodized alloy plate. This
is bonded to the machine's thin wrapped sheet alloy side wall by metal-loaded epoxy cement.
This dividing plate one assumes is for both structural and screening purposes. The top
electronics compartment situated directly under the transport contains the audio record-replay,
video record-replay, time code, DC power distribution, and syscon printed circuit boards. The
lower compartment under the dividing plate, contains the electrically more noisy systems of the
switching power supplies, motor commutation, digital bus, and reel, capstan and scanner servo
system power drivers. All these surface-mount circuit boards are 'bolted' to the various surfaces
with the usual white Nagra slotted plastic 'nuts'.

The base plate itself is another example of the interesting manufacturing values employed in this
machine. No simple plate this, but a complicated nest and heat sink for all the power circuitry
built onto its inner surface. Around the periphery of this plate is another large elastomer O ring
seal, and nesting within are 13 circuit boards, a selection of torridial inductors and power
transformers together with 46 TO220/MJE packaged power transistors and asorted MOSFETS.
The special Lithium 6 Volt battery pack for time code and syscon backup also lives here. The
circuitry is very neat and compact, though must also have been a nightmare if any dimensionally-
critical component became un-available. The transport surround and base plate form a stressed
box section structure for the machine and must have the various fixing screws tightened and
released in an incremental way, rather like cylinder head bolts of a car engine. In fact when
tightened up, the whole machine becomes a very tough metal sandwich. (I wouldn't like to drop it
though!)

On the under surface of the machine there are no simple mounting feet as such, but an undercut
rectangular recess at each corner. These are designed to accept various special mounting
fixtures. For field use, the padded working case has 2 alloy fixing strips that turn-lock into these
recesses to hold the machine securely. Or one can by similar means lock the machine into a
special back-pack harness frame. In a mobile 'scanner', in the studio (or aircraft?), one might be
expected to fix the machine on to its own special anti-vibration table mounting plate, or slot the
machine into a special rack-mount box. (The recorder slides in sideways on rails.) Naturally, the
machine's carrying strap which is rather like part of a military jet's seat belt harness, has its own
special spring-loaded, machined-from-the-solid-and-anodized fixing locks. (But what else?)

My conclusion is that the Ampex / Nagra VPR-5 has to be one of the finest examples of electro-
mechanical design there is. It has a purity of form that reflects the considerable intellectual
achievement invested in it. Highly expensive and exotic when new and now obsolete and nearly
forgotten, it does though remain a very pleasing and wonderfully tactile sculpture in anodized
alloy. (Actually it would probably look quite at home in a modern minimalist apartment!) Vastly
in advance of their audio recorders of the time it is a bit of a mystery how it came to be made at
all and remains an anachronistic statement of true engineering values, made all the more
impressive for the quality of results that it is still quite capable of. Described by one owner 'as a
work of art', and another as 'the eighth wonder of the World', it was rendered too soon un-viable
by unfavorable external circumstances. Deserving perhaps to have been more long lived than it
was, it is now rare and of currently moderate value.

You don't have to have any interest in old television kit to appreciate or perhaps desire to own
one of these beautiful little boxes, just have some seriously good taste.

Bravo Nagra and Ampex! - and my compliments to the reader having got this far...

The text and pictures on this site (excepting the leaflets, and Mr Marriott's images) are my
copyright. If you make use of them in any way, the decent thing at least to do is to acknowledge
the fact.

Gino Mancini, May 2005.