•  Radio and Audio equipment Repairs (since 1985)

  • Restored Cobra 148 GTL DX

    Cobra repair and restoration

    This radio shown above came to us with a damaged case and front bezel , no TX power output, and an intermittant problem of the meter pegging out at full scale deflection while on receive.

    As you can see from the above picture we were able to repair the faults and restore this radio to its former glory


    Contact me on

    First Name: Nick

    Phone: 07770  397668

    Text:      07770  397668

    E-mail: np262@yahoo.com

    Address: 8 Pouces Cottages, Spitfire way, Manston, Kent, CT12 5BU.

    We welcome customers in Europe, USA, and Australia; if you wish to contact us please phone: +44 7770 397668

    I would like to bring to the attention of our valued customers that due to an unusually high volume of work and the nature of that work I am receiving at this time I still have the intention of achieving a turn-around of radio repairs within 16 weeks, but Radios which have had failed repairs by other poeple, specialist upgrades requiring the designing, manufacture, and construction of custom components for example UK 40 boards, Continuous Tone Coded Squelch System Boards (CTCSS), Roger Bleep Boards, etc. does take a lot longer to install and test; and in the event that we have to source hard to find components for the older radio equipment or communications equipment that has a habit of self destructing when it fails can also lead to significant delays in the repair time of radio or as is becoming more common a complete rebuild if the radio rather than just a repair. 

    If you would like an update on the repair of piece of equipment you have sent to me then please e-mail me at the normal address shown above.

    Marconi Signal Generator

    I have just purchased a Marconi Signal generator, as you can see I am just giving it a test on the workbench before moving it to its new home ready to be used.

    It is bigger than I expected, but it will provide additional features including CTCSS tones that we didn't have access to with our previous signal generator.

    Vortex Antennas

     We are please to recommend Vortex Antenna Systems for all of
    your  Antenna needs.

    Magnum Delta Force

    We have an interesting collection of Radio’s this month in for repair, so I have highlighted the Dragon (Magnum) Delta Force, it came in with the normal SSB signal meter Full Scale Deflection  with no signal present, and Weak Transmit Audio on SSB.

    Ham International Jumbo

    Another Radio that we have not seen for a while is Jumbo, it
    arrived with no receive audio on SSB/AM and wouldn’t transmit on all of its channels.

    Galaxy Saturn

    A visitor to our Facebook page commented on the Ham International Jumbo, well I have posted a picture of one of the later replacement radios which I have just finished.  Notice I shown this radio transmitting on FM.  I really like the addition of the Frequency counter so you now have an idea on what frequency it is transmitting.

    President Madison

    I didn’t want everybody to think that I can only repair Cybernet based radio’s, so here is a Uniden based radio I have been working on in the last few weeks.

    President Grant

    This radio came in with digits out on the channel display; after inspection it was clear that the meter lamp was not working, the meter
    only sort of works when it feels like it and the radio was slow to go into transmit mode.  After some TLC the channel display has been replaced, the channel switch was cleaned the meter lamp has also been replaced.  A new set of Electrolytic capacitors has fixed all of the other problems.

    President Grant II

    This is the next generation of the Grant which has come a long way from the 1970's version. I don't get many of these radios in for repair because they tend to be reliable unless someone has had a fiddle with them.

    President Grant (PC-409)

    This radio came in with some minor problems, but I was surprised to find that this was the earlier version of the President Grant which normally has the PC-999 board in it as shown above; you can tell this is the earlier version of this model because the microphone gain control is only a single control and not a dual control, and because the radio is by default mono-band so the band control is missing although all of the radios that I have seen have been converted to two band versions.

    President McKinley

    This is another rather good mobile set; this time having the
    same Uniden board as the Stalker 9, but not being a Stalker 9 has the UK40 board mounted on the left hand side of the case.

    President Lincoln

    I have been working hard over the Christmas 2016 holidays,
    with a lot of my ordered components arriving altogether. This is a finished President Lincoln which has had a new PA Output Transistor and Driver Transistor after it was found that the Output Transistor was fake and the other had blown.

    President Lincoln

    My latest President Lincoln that came in for repair which looked like a simple problem, but turned out to be very time consuming when the Electrolytic capacitors had started to leak all over the printed circuit board, and several of them had gone completely short circuit and had blown some of the components on the other boards.


    President Lincoln II

    This radio came in with no transmit audio.  It looked like a microphone plug failure had caused the 13.8v supply to go to places it was never intended and the result was the microphone audio signal tracking had gone open-circuit and the microphone dual bilateral switch IC had blown as well. 
    The microphone dual bilateral switch being a small surface mount IC
    great care was taken replacing it on the radios main board.

    Nato 2000

    I have had lots of fun repairing this set, being one of the only sets other than the Stalker 9 with the UK 40 built in as standard.

    Kenwood TS50

    This second Kenwood TS50s I have seen in the last few years
    in the workshop, when they are working they are a very good example of small mobile Amateur radio HF transceiver.

    Unfortunately by the time that I get to see them they tend to be very much worse for wear; the first one I repaired had 34 separate faults spread across the whole of the radio, fortunately the radio had not been screwdrivered so it was just a matter of finding the failed components and replacing them.

    You have to be aware of fake Chinese components for these radios
    because they just don’t work, and this is an all surface mount radio so unless you're happy with a hot air re-workstation and a fine tipped soldering iron working on these should be left to the professionals. 

    Kenwood TS-940S

    This came in with the reported “dots” on the Display which
    is the PLL out of lock problem, but when I took the radio cover off the power supply had completely blown all of its components off the board in into the radio.  The power supply boards are no longer available ether new or on the second hand market so decided to completely rebuild the power supply from scratch. This repair took over a year with having to source some of the components internationally and for the components that are no longer available finding equivalents components that were still available. Once the power supply was operational I found that the fan control
    circuit had failed so a rebuild of the fan control circuit, a service of the
    fan itself and I lowered the fan turn on temperature to 30 °C to help to keep the radio cool. I moved on to repairing the negative voltage inverter which had also stopped working.


    Yaesu FT 767GX

    This is a FT767GX with the 2 meter and 70 centi-meter modulus installed in it; It has taken a few weeks to identify why the ATU was not tuning at all, and the SWR wondered about while it was enabled, and the modules in the back reported to be transmitting 10 Watts but in fact they were only
    producing 1-2 Watts.

    Yaesu FT 757GX II

    I have been having a lot of new faults with the FT767/757
    radios I have been looking at recently, problems with the Phase Locked Loops (PLL) going out of lock, and mixer components failing.  This 757 came in with a collection of strange faults including cracking on AM, No transmission on any band or any mode, and
    the meter lamps had failed.  This is of course a complete departure from the well documented diode failure these radios suffered from in the early days. 

    Yaesu FT 757

    I have spend a lot of time repairing the Yaesu FT 767 radios, and one day a FT 757 turned up for repair, it had No Receive, No Transmit, and No noise out on FM.

    After inspecting the radio I discovered that something very strange had happened to this radio, with the Transmit and Receive  8v supplies being present in both transmit and receive, the switching diodes had also gone, but I expected that this is a common problem with the FT 7*7 modes of radio.

    A collection of additional components had been found on the bottom of the board RF Board, and PA Board but didn’t appear to perform any useful function and so they were removed and the radio was restored to factory defaults.

    Some thirty separate faults later and being realigned because someone with a screwdriver had had a go as well this radio is again up
    and running.

    Yaesu FT-One

    A 1982 Yaesu HF Set which turned out to be one of the longest repairs I have ever taken on, this radio was not transmitting the full amount of power expected and worse still was not operating on the same frequency as displayed on the frequency readout and it also changed as you changed modes as well.

    FT 840

    This radio came in with a flashing LCD display, a classic PLL Out of lock indicator.

    The problem was traced to a failed power supply on the Local Board which included a number of failed electrolytic capacitors, burn tracking and pc board, and numerous failed solder joints.

    After some careful and time consuming replacement of the failed components and the repair of the printed circuit the radio was returned to an operating state. 

    Cobra 148 GTL DX 

    I have had one of the best examples I have ever seen of a
    Cobra 148 GTL DX, which had not been screwdrivered or seriously modified, so I had to photograph it and show you all because this is a once in a life time experience.

    Cobra with a fitted Frequency Counter

    I have just serviced this Cobra as well as installing a Galaxy frequency counter.  The frequency counter is supplied with the ability to be screwed to a desk or shelf, or if you prefer comes with pads to stick it to the top of the radio. This frequency counter is the latest version supplied in blue and gives you the additional digit over the previous model fitted as standard into the Superstar 3900.

    Superstar 3900

    This radio came in to have the new UK40 Board fitted and as
    you can see worked perfectly; I also did some routine repair work which came to light when the covers were removed and the radio was tested.

    Ranger Mirage MX25

    I have just wide banded the Mirage MX 25 and as you can
    see you now get Frequency readout, and I have tuned the radio to the High Band Channel 12 (27.555 MHz) for demonstration purposes.

    Midland 7001

    You are looking at a rare Midland 7001 multi-mode radio in very good condition sitting on the test bench; it came in with no Tx/Rx, and after a lot of work I am pleased to report that it has come back to life.

    Galaxy DX 66 

    This radio has had some interesting modifications performed on it some of which I have had to repair, so I just couldn’t resist posting a picture of the finished radio.

    TTI TCB 880

    This radio came in with many problems the first being that the
    radio turned on with the LCD display performing its self test, but the radio didn’t transmit or receive anything also the LCD back light was not functioning.

  • A Full Amateur Radio Licence
    holder who passed with Merit.


    I would also like to announce that I hold a full Amateur Radio Licence with the callsign M0NKL which I achieved with a merit.

    FT101E restoration and repair

    A picture of me in my workshop working on a FT101 restoration and repair, which is going well.

    Fake 2SC1969 Transistor

    Fake components  

    We have been receiving a number of radios with failed Fake 2SC1969 transistors installed into them; these transistor work intermittently for a short period of time and then failed causing no RF power output.

    If the printing on the transistor is of poor quality then it's going to be a poor quality transistor.

    The date of 2015 is clearly impossible remember they were not made after 2006 so a date of 15AD is impossible.

    Fake Components

    We have been receiving a number of radios with failed Fake 2SC2166 transistor installed into them; these transistors work intermittently for a short period of time getting very hot, and then failing causing no RF power output.

    This one had 2.5v across the Base-Emitter junction and still measured correctly when I removed and tested it. If the printing on the transistor is not straight then it's going to be a poor quality fake transistor.

    Fake Components

    I have had the first one of these components arrive at the
    workshop in a non-functioning radio today and I have looked around and they are now appearing on EBay; it appears that the transistor Identification Number is not printed but etched onto the surface of the transistor case.  I am sorry for the out of focus picture but I had lots of problems photographing this component so that you could see the identification number. They have the same problems as all of these Fake components in that
    they produce very little to no power, get very hot very quickly, and then blow short circuit collector to emitter.


    Fake transistors hFE.

    Another indication that your RF transistor is Fake is seen if you measure the Current Gain (hFE), for the 2SC2312 the data sheet states the best current gain is 90-180 with the “DD” ident, but you will normally see the 55-110 ident “CC” with a measured gain around the 90-105 in CB radio sets.

    The Fake 2SC2312 transistor shown above has a current gain of 262 which is just impossible for an RF Power transistor; clearly whatever is inside the package this is not a 2SC2312 transistor.

    Fake Components

    I found this power transistor in a FT 857D in the VHF/UHF power amplifier, unfortunately after repairing the UHF fault the radio only transmitted a few over’s before this fake transistor failed.

    The picture above is a E-Bay seller with a worst Transistor than the one I already have.

    The giveaway is that the printing is heading for the bottom right hand
    corner, is not straight, and the logo and text is smaller than on the original.

    A genuine Mitsubishi transistor is shown below.

    Genuine Mitsubishi

    I have written a lot about fake transistors so I have taken the time to pull two genuine  transistors out of my radios so you can see what the transistors look like, the key things to look for on the Mitsubishi is the “CH” which is the Hfe of the transistor, and comes in “A-D” followed by “H” with C being the most common. The date number 99 or 0 for the year 1999/2000; remember they were not made after 2006 so a date of 15A is impossible.

    Realistic TRC 44A 

    I thought I would share with you one example of what I have
    been repairing this month which is a Realistic TRC 44A in excellent condition.

    Icom IC-740

    This radio came in without any transmit output power, it was
    discovered that a number of faults had developed over time, and were successfully repaired after which transmit on all modes was restored.  The normal checks were also performed as well as the On-Air test.

    Icom IC-751

    This radio came in with no display, no receive, and no
    transmit, and turned out to be one of the longest repairs I have undertaken.  It initially looked like the battery had gone flat which is a common problem with these radios, but it turned out to be loads of problems with various internal power supplies, and the PLL was also out of lock.  The finishing touch to this repair (shown below) was a new meter high brightness LED, and some new screws in the top case cover.

    Icom IC718

    A friend called in to see if I could fit his CR-338 high stability crystal into his Icom radio.

    Noise Cancelling Signal Enhancer
    This is another of the special non radio repairs I have been undertaking this month, an interesting repair with some very difficult to find transistors in it.

    Tokyo Hy-Power HL-45

    I have just changed and re-biased the Power Mosfets in this Tokyo
    Hy-Power RF amplifier, this is the first one I have done as there are not many of these quality products about these days.  The picture shows it transmitting 40 Watts output for 2 Watts of drive.

    Microwave Modules 144/30 LS

    This Amp came in with no power output, the transistor tested alright, but the bias current was set to high so I turned it down to a more reasonable value, further investigation revealed a failed component which was replaced and normal transmit function was restored, the Rx amp was also tested to confirm that it worked.

    RM Italy KL203P 

    This power amp came in with the Rx Pre-Amp not working.
    A relatively simple problem to fix, the difficulty is getting the covers off and back on again without scratching them.

    The top picture shows the power amp transmitting with 4 Watts drive.

    The next picture shows the through signal from my signal generator with the pre-amp turned off.

    The bottom picture shows the signal after it has been amplified
    by the pre-amp.

    Pre-Amp Off; signal generator signal. (-40dBm)

    Pre-Amp On  ( -26dBm a gain of +14db)

    RM Italy KL405 

    This power amp came in with the Rx Pre-Amp not working. A relatively simple problem to fix; the difficulty is getting the covers off and back on again without chewing the screws.

    The top picture shows the power amp transmitting with 4 Watts drive and the next picture shows the through signal from my signal generator with the pre-amp turned off.

    The bottom picture shows the signal after it has been amplified by the pre-amp.

    Pre-Amp Off; signal generator signal. (-32dBm)

    The test gear was left in the same position for both RM Italy KL203P & KL405 amp tests so I can only conclude the better through signal on the KL405 was due to better internal construction.

    Pre-Amp On  ( -18dBm a gain of +14db)

    CB Radio Spectrum Displays.

    I have been looking at the output of the CB sets I have been
    servicing in the last three months, and have captured some spectrum output displays.

    I have used one of the best Cobra 148 GTL DX Export models I
    have seen in a while, with the only mod being you can turn the power up from the front panel from 0-16Watts.

    The frequency I used for the tests were Channel 19 Mid Band
    27.185 MHz driving a 50 Dummy Load.

    The first image is of FM mode with no modulation with 4
    Watts output, the correct setting for this set.

    I have now used the mod to turn the power up to its full output of 16 Watts, and am really over driving the Final PA stage producing lots of harmonics because of the distortion of the signal which appear as the vertical lines on the display.

    I have to ask myself although my Power meter is showing 16 Watts, where am I producing all of this power, it’s clearly not going into the carrier frequency, but is being transmitted as unwanted signals on the channels either side of channel 19.


    Also notice that the carrier signal has dropped from +10db to
    -10db as well!

    This picture shows the correct power output of 4 Watts FM,
    with the second and third harmonic output being -40db and below.

    AOR AR5000

    This receiver arrived with a unable to receive on AM or
    SSB fault but FM is received alright.  You can see from the signal meter in the picture that after a surface mount component repair the receiver now receives AM without any problems.

    Drake R8E

    This radio came in with a no receive fault, after performing a quick inspection I found two of its electrolytic capacitors had leaked electrolyte all over the corner of the board and was eating the top tracks off the board. This was quickly cleaned up before the problem got any worse. The receiver had several faults which were identified once the receiver could be operated in safety. It was not possible to perform the normal On-Air test so I had it on in the workshop tuned to Radio Caroline.

    Trio TR-7930

    This is a 2 Meter mobile transceiver from the early 80’s, it came in with a range of problems including the inability to enter any frequencies into the radio via the keyboard, all the lamps had blown so you could not see what was on the display, and there were a number of failed capacitors.


    The radio pictured below is the second one that came in the
    same consignment, but is somewhat worse for wear, apart from the normal problems the radios PA block has blown so it only transmits 15Watts as shown on the power meter, and someone had tried to change the CPU and had gotten into difficulty while doing it.  This repair took lot of time but keeping a old piece of equipment going is well worth it. 

    Trio - TR9000

    Here is an example of a Trio Multi-mode radio from the early
    80’s, this radios being mono band incorporates  a three pole band-pass cavity filter which filters out the out of band noise which we are all suffering from these days much more effectively than “The rig in a box” is able to do.

    Kenwood TS850

    I have been repairing a few TS850’s, all of which have had leaking capacitors on the DDS board and other problems. I am quite good at getting the surface mount capacitors off the board without ripping the track off, but you still have the problem of repairing the corrosive damage that has been caused and if you are really unluckily the DDS chips themselves which also fail. 

                            Related info

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    What we repair



    Amateur Radio repairs.




    FM and Multi-mode CB repair.




    Valve & Transistor power RF amplifier repairs.



    Audio amplifier repairs.

  • I have been repairing radio equipment since the early 80’s in the days of the PMR conversion of Pye Westminster’s, and CB radio was in its infancy in this country,  I later became interested in Amateur radio, and this lead to my repairing of amateur radio equipment. I specialise in the repair of multimode equipment at component level, with resolving the more difficult problems being what we spend most of our time doing.

    We also do a range of radio programming including the Chinese manufactured range of handhelds and recently Kenwood mobiles.