Project: DSE K5415 Video Fader & Wiper Kit (EA 4/98)

This weekend’s been quite a busy one, especially as I’m starting to sink my teeth into a number of RoadTest reviews. But it turns out that this weekend is also the weekend in which I have have finally come to the end of my Dick Smith Electronics kit journey, completing the final kit I purchased from the Wyong Central Coast Amateur Radio Field Day.

The Kit

The kit is flanked with a blue label, as part of the Audio Kits series. This kit is the K5415 Video Fader and Wiper Kit, based on the article in Electronics Australia Magazine of April 1998.

According to the side panels, it features the ability to produce manual fades and wipes of the horizontal or vertical variety, to any shade of grey/black/white. It also has a “high peaking” enhancement facility to compensate for loss of high-frequency content in dubbing and can disable the fade/wipe feature for enhancement only. The kit comes in the largest box of all of the units I’ve recently built – that’s because it comes with the components, PCB, plastic case, hardware, power adapter, pre-punched and screened front panel and rear panel label.

Unpacked, this is what it looks like. A lot of knobs, a large front panel, a case with a sloping front and a DSE multi-voltage wall-wart adapter. Definitely would have been the priciest kit of the lot.

As with the other kits, there is a black-and-white assembly manual along with the disclaimer and quality control cards. This one is stapled with two staples, consisting of a few more pages than usual. This one is marked Edition 1 in the top corner.

It’s almost as if they meant to write Edition 1 up there, as I found these two pages had repeating text and as a result, some of the alignment instructions are actually missing in this manual. No matter, I’m sure we can figure it out eventually.

Unlike the other kits, the front cover of the Guide to Kit Construction is a little different. I realise that I’ve never shown what’s inside the manual, so I picked two representative spreads to show – despite the cover difference, the contents are unchanged.

Contained inside is information that informs kit construction and basic troubleshooting. As a sign of the times, everything is black-and-white, consisting of high-contrast photographs and line-art drawings. A “typical” multimeter of the era is a moving needle type, as shown in the image … not so typical nowadays.

The prefabricated front panel is a heavy piece of steel with a very nice grey finish for a professional look. The screen printed labelling also looks very attractive. Having the holes pre-drilled is a big help as well. The rear label is a lot less exciting by comparison.

Rather unfortunately, the single-sided, non-silkscreened, non-solder-masked PCB supplied was a bit sub-par. The tin plating was uneven, with blobs which covered some of the drilled holes. The tin plating also tarnished in parts of the board as well.

Compared to the other projects, the board is rather substantial, with quite a number of ICs. Also, due to the need to handle higher frequency video signals, it seems it has been designed slightly differently with wide ground planes and small dimples cut out of it to act as thermal breaks to limit heat-sinking from the soldering iron and solder flow.

The case is unlike the other basic jiffy/zippy boxes – this is more akin to an instrument case with a sloping front and comes with a heavy aluminium front panel and raised rubber feet. Very nice.

Construction

Construction is relatively straightforward, with all through-hole components. The only difficulties were related to the tarnishing and oxidation of the PCB, the IC socket legs and some tin plating obscuring drilled holes.

Regardless, I commenced with constructing the PCB. The circuit operational theory is almost visible on the ICs alone which includes a few gates, a sync separator and some timers. Unlike the other kits, this one deals with a fairly high-frequency signal by comparison, so I’m not quite convinced such a design would be optimal for video being quite large and unshielded. That will become apparent later.

The board was completed with my flux-ey solder rather than the solder it came with – the solder it came with is more like my DSE super solder which has a clear flux but is not as aggressive.

My next step was to construct the front panel by mounting the switches and potentiometers onto the front plate, then mounting the whole plate to the top of the chassis along with the rear body label. This step was fraught with a little difficulty as the knobs fit on the multi-position switches with some resistance – I pushed them down which resulted in the switch assembly disassembling itself and the ball bearings responsible for the ratcheting action pinging across the room. It took me a while before I found them and reconstructed the switch.

My next step was to mount the PCB into the base of the box, drill out holes for the BNC video in and out and power and connect them to the board. Unfortunately, my choice of BNC location was not the best, as they encroached on a support tab which I needed to cut away to be able to firmly screw them in. Now it comes to the really daunting part – the front panel wiring.

There are a lot of wires to go between the board and the front panel, along with the resistor and capacitor that had to be mounted “air-wire”. Unfortunately, I got the connections to the switch the wrong way around, so had to rotate the switch around resulting in the strange wiring job. I also tried to avoid wires for the resistors and capacitors, leaving their legs to do the work. Regardless, the wiring was correct, even if a little messy.

Finally, the unit is constructed. Quite professional, although modern products would not be built using this sort of material anymore.

The sloped box really does present a more “ergonomic” interface.

The sloping rear isn’t necessarily the best though, as this puts the BNC connectors on a slight downward angle which could result in clearance issues if the cables had large rubber boots.

My mis-positioning of the BNC connectors is clear – the video out should have been more to the left. But there’s no going back once drilled … so I had to live with it.

This time, I countersunk the board mounting screws with a 6.5mm bit and they sit perfectly. The supplied rubber feet are still good and the screws hold the halves of the case together.

Testing

In order to test and align the kit, I had to obtain two BNC to RCA plugs, as the choice of plugs on the kit are not the ones commonly used today. Only earlier VCRs had BNCs by default. Regardless, with this, I was able to film a short video demonstrating it in action after aligning the white-level, sync pulse level, vertical and horizontal wipe periods.

While it does work, I suspect the lack of shielding and amount of local RF interference is what causes the occasional speck or fleck to show up on the screen, despite my effort to try and reduce the amount of unshielded video cable. This is because there is so much unshielded wiring from the board to the front panel and back to contend with as well.

Conclusion

The Dick Smith Electronics K5415 Video Fader and Wiper kit was the largest kit I had attempted from Dick Smith. The kit basically works around a chip which does sync pulse detection, sets of 555 timers which produce a time offset relative to the sync pulse and gating/masking the video signal based on a generated voltage level. As a result, the kit basically works on a “line-by-line” basis. The construction and alignment involved many steps, although most of them were straightforward, this was not helped by errors in the assembly manual. Despite this, the build was successful and performed the functions as promised although necessitating finding some BNC to RCA connectors to adapt the connections to something “more modern”.

It’s a bit of a sad occasion, as this is the last kit in my stash of Dick Smith Electronics kits. At least they have all bought me some joy and nostalgia in the process of building them, even though by now, their functionality is all but obsolete. It also reminds us of the potential simplicity of analog compared to high-bandwidth digital signals of today.

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One Response to Project: DSE K5415 Video Fader & Wiper Kit (EA 4/98)

  1. sparcie says:

    Watching the video I actually thought this kit did a pretty good job, better than I expected. Of course it could be that the defects it introduces don’t show up well in a you tube video. Given the low quality of many VHS recordings it may have not been all that noticeable.

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