COBRA

TRANSCEIVER 
MKV

JENTEC
COBSCAN
SUPERSCAN
TRANSCEIVER MKV

The COBRA TRANSCEIVER MKV (MK5) 
was not a Cobra Factory production model.
 The COBRA TRANSCEIVER MKV was instead a 
"Concept-Transceiver" 
literally years ahead of any 10/11 meter radio of it's Genre. 
The Transceiver MKV was crafted into creation by a 
true Genius called 
Mr. John Nugent 
(Amateur Radio Callsign G1LFY.)

 John traded under the Business name 
JENTEC
JENTEC was an acronym for "John E. Nugent TEChnology". 
John lived in a town called Plaistow, located in 
the east part of London, England. 
John made only 280?* MKV's and today they are VERY rare and good examples almost impossible to find.

The Cobra TRANSCEIVER MKV started out life as a MKII Cobra 148GTL-DX PB010AA/AB chassis.

Conversion Process
The Cobra 148 GTL-DX had the PLL stage components removed from the main PB010 PCB. The Channel Selector complete with Channel Indicator LEDs and TX/RX LED were removed. 
The Channel Indicator LEDs location on the front panel was expanded to house the MKV Frequency Counter PCB see below. 

John then designed a 5-Digit Frequency Counter and TX/RX LED PCB and furnished it with a Digital Incremental Encoder for the Channel Selector that has an unrivalled performance and unique feel make it a pleasure to operate. The Digital Incremental Encoder has a very smooth feel to each turn of the control. Unlike the standard 148 Channel Selector with 40 positions the MKV Encoder has 50 thus expanding the tuning range by 25%.

 JENTEC
COBSCAN
CONVERSION BOARD























John's pure Genius was in designing the 
Jentec Cobscan Conversion Board, which essentially 
made the MKV unique from any other Transceiver. 
Fully-Digital, several different versions of the 
Conversion Board were produced by John Nugent, 
each PCB was an improvement on the previous version.

The below JENTEC COBSCAN PCB was actually the first design 
and was fitted only in the 1989 released 
Cobra Transceiver MKIV (MK4). 
Notice the 4Mhz Microprocessor and row of ten variable potentiometers used for alignment.

The next Version of the JENTEC COBSCAN PCB is shown below.

John called this the MKIV 060489 (MK4) dated 6th April 1989, updated now with an 8Mhz Microprocessor. John also called his Software written into the Microprocessor the "SCAN 50" Series. Several versions of SCAN software were released, SCAN 52, SCAN 58 etc. The below Processor was programmed with the SCAN 58 Software on the 28th Febuary 1991.

Following the success of the two previous versions, John made the final PCB shown below, this is the JENTEC COBSCAN 060393 MKV dated 6th March 1993. This PCB utillised surface mount components SMT, has double-sided print and was a third smaller than the previous designs. The below Processor was programmed on the 10th February 1996 and was sadly one of the last MKV's made by John.

MKV COBSCAN PCB solder-side below.

JENTEC EPROMS














SCAN 5 SERIES SOFTWARE

 The dates written on the Microprocessors were by John Nugent himself. Inside the MKV John also attached an individual Serial number to the Transceivers he modified. The dates and information on the Microprocessors show the development, over time, of the SCAN 5 Series Software. The below 4Mhz Microprocessor is utilising the SCAN 52 version of the software dated 11 October 1990.

In only 4 months (October 1990 to Febuary 1991) John had developed the SCAN 52 software into the SCAN 58 revision and upgraded from a 4Mhz Microprocesor to an 8Mhz Processor. See above & below pics.

SCAN 7 SERIES SOFTWARE

By early 1992 John had developed the SCAN 75 version of MKV EPROM programming code. Various bug fixes were published in this release, the below picture shows an Eprom dated 14th January 1992 containing SCAN 75 MKV software.
 

The Holy-Grail of the JENTEC TRANSCEIVER MKV is the 
SCAN 5 & 7 Series Software. The SCAN 5 & 7 Series was 
developed and improved with later revisions 52, 58, 75 etc 
allowing the Processor to control all the complex tasks 
associated with the MKV. Below is a screen shot of the actual 
HEX data from a SCAN 58 Eprom.

FACIAS

The Chrome Bezel from the original 148 was used and John created a new Transceiver MK4/5 Face Plate and modified the Channel Indicator LED space on the Bezel to incorporate a 5-Digit Frequency Counter with Diffuser in GREEN or RED. 
(see above/below pictures).

MKV SPEC

The Cobra Transceiver MK5 boasted a host of features, many unavailable to any 10/11 meter Transceiver at the time. 
Here is the full list of features:

Volume

Squelch

Mic Gain

RF Gain

Variable Power

26-30Mhz using 4 position Band Switch

CW.FM.AM.USB.LSB

1Kc RX/TX Clarifier

Scan Facility, UP/Down, 
(could stop on a busy channel if using squelch)

Timed Scan resume

Astatic Teardrop with UP/Down buttons could 
Scan/Change Frequency UP/Down

10Kc - 1Kc channel steps

Repeater shift

+/- 100Kc Repeater offset

S/RF and Power S-Meter indication

5-Digit Frequency Counter (Red or Green)

TX/RX LED

Big Heatsink on rear panel

Zero-40 watts AM/FM variable

Zero-40 watts SSB

PB010 Cobra Chassis

 John Nugent tragically died in 1997, 
his contribution to CB/Amateur Radio has been incalculable.

*Interestingly, John only modified 148's sent to him personally. John didn't buy 280* MK2 148's and mod them, counter to popular belief. Only operators/148 owners who knew of John and how to contact him, as he did not advertise, were the lucky few who owned a MKV purely by word of mouth. John later sold MKV 
"JENTEC COBSCAN Kits" so you could 'make your own MKV'.

URBAN MYTHS

Recently Cobraworxshopz have heard it suggested that the different colours of MKV Frequency Counter LED's (Red & Green) were significant and showed if the MKV was 
made by John or was the 'build your own' Kit version. 
Another suggestion that made us here all laugh out loud, is that Cobraworxshopz infact made the Green Version!.
  
Typically none of the above Urban Myths are true in anyway, 
just nonsense made up by the usual attention seekers.
 
Straight facts are the Green LED versions were designed around a different type of 7-segment LED display and the digits were physically smaller than most Red versions* hence a different JENTEC
Frequency Counter PCB was used on the Green MKV's, 
all constructed by John Nugent.
*note (some Red MKV's were also supplied in the small digit sizes)

BLUEPRINTED

  Cobraworxshopz.com Technicians have Mastered the 
"JENTEC COBSCAN" Transceivers made by John.  We pride ourselves in having the MKV "BluePrinted" and with most parts in stock, we can repair, maintain and service the MKV completely.  

MKV JENTEC SERIAL NUMBERS

All Cobra Transceiver MKV's had a small white sticker attached to the speaker side of the case with a serial number and date, 
hand written by John.

 





























MKV ANTI-TAMPER SEALS

In an attempt to stop "Screwdriver-Experts" 'improving' the MKV, John added some ANTI-TAMPER Seals to the Transceiver cases.
The Seals were made of a white-coloured circular sticker placed on either side of the cases. The Seals were similar to a kind of paint and would easily break if Tampered with as seen below.














Cobraworxshopz.com Technicians offer several Special Mods ONLY available for the MK4/5 Transceivers. 
We also have the Full Cobra Transceiver MKV operating manual and technical guide, written by John Nugent himself, 
a must for any owner or Radio collector, 
avaliable to purchase from Cobraworxshopz. 
Please call or email us to get yourself a copy.

Cobraworxshopz.com are often asked 
three questions regarding the MKV.
 
Firstly do we have any for sale, secondly can we 'make' a MKV and thirdly how much money are they worth???

We do on occasions have MKV's for sale, not our own but customers MKV's who are willing to part with their highly sought after Transceiver. These will be advertised on our website under the 'For Sale' tab or in our Ebay shop.

 Transforming a COBRA 148 GTL-DX into a COBSCAN TRANSCEIVER MKV is an incredibly time intensive operation and takes many, many hours and requires multiple engineering and electronic skills to complete the conversion. Unfortunately Cobra Transceiver MKV's are not a financially viable product to produce today because of the sheer amount of time involved in the conversion process, hence Cobraworxshopz.com does not currently offer full conversions.

The price today of a Cobscan Transceiver MKV varies greatly depending on it's general condition and functionality. MKV's with faults in non-working states generally fetch £200 or $375 on eBay and 
100% working condition MKV's presented in original condition 
£600+ or $1100+ 
Of the 280 MKV's John Nugent converted 
how many still remain out there ???

Click on the picture below to see a working Cobra MKV

Please contact Cobraworxshopz.com for all Cobra Transceiver MKV Repairs, Spare Parts and Mods.

Telephone UK on 07508-148-148 

"THIS MAY BE OF SOME HELP, John"

This page is a work in progress and as such will be updated at any time
COBRAWORXSHOPZ