Kent TP1-B ‘iambic’ twin CW paddle kit – review

Updated May 2021 – see below

A group of BBRC members including myself recently started to learn (or re-learn) Morse code. I’d been wanting to brush up on CW for a while so decided to have a go. I had a Chinese UniHam Uni-730A dual paddle (iambic) key I’d bought via Aliexpress a few years ago. It was fine to get going with but didn’t allow much range of adjustment. Morse keys generally allow adjustment of the contact gap and the tension of the spring (or magnets) holding the contacts apart. On the UniHam, there was no way to adjust the tension and the screws to adjust the contact gap were very difficult to adjust. Also the minimum gap seemed a bit on the wide side.

I spent ages looking at keys and reviews online. Many key are prettier, gold or chrome plated affairs but after reading one reviewer saying they preferred their Kent dual paddle key to their Begali Magnetic Classic I decided to go for the Kent  paddle. It seemed to be decent quality and weight (just under 1.2kg). The current model apparently has an extra screw holding the fingerpieces as well as beefier arms than the earlier one which apparently felt a bit ‘soft’. Kent offer their keys fully built or as kits of parts and I decided on the latter. It looked like fun* and saved almost £20. The company offers a range of straight and dual paddle keys as well as a rather homebrew-looking electronic touch paddle and keyer combination costing a mere £38.50 + VAT & shipping. Kent also sell a full range of spare parts for their products.

There is one slight oddity about ‘R. A. Kent Engineering’. At the time of ordering, pre-Brexit, prices were all in pounds sterling and their website made them look like an old-established English family company. In fact they are now based in Germany, which expains the slightly steep £12.70 cost of shipping. And the baseplate label saying “Kent Morse Keys Germany”. The shipping label said “Kent Engineering Inh. Robert Kent”, so it looks like Robert Kent still owns the company.

The full kit

The Kent twin paddle kit comes with the trickiest part already done – the bearing block assembly is mostly pre-assembled and has the arms and 4 bearings already in place. I imagine a beefy press is needed to put it together, so self-assembly may not be very practical in any case. Including the bearing block there are 50 parts in the kit plus an allen key, which is used for two tiny grub screws. All the parts seem well made, mostly of brass. The contacts are silver and are decently sized. The heavy baseplate has a shiny crackle finish. A length of 3-core cable is provided but no plug. After putting my paddle together I noticed the manual for my Kenwood TS-590 specifies screened cable, so I may change that at some point. The paddle doesn’t come with a cover, unlike some other makes. Nor is one available as an option, although there is one available on Ebay.

Assembly was quite easy although it took me a few minutes to work out where and how to use some of the parts. The single A4 page of instructions are good (you can see them here) but they aren’t very explicit on one or two points – for instance which way up the base goes. This was obvious once I’d realised there were extra tapped holes for the feet and cable clamp but there was a bit of head-scratching initially. It also wasn’t easy to tell a few of the screws apart until I realised the brass ones go on top and the steel ones underneath! The fingerpieces can be attached either way up. I fitted mine hanging down. Assembling the tension components was slightly tricky without the adjusting nuts fouling the screws holding the fingerpieces. Similarly it seemed easy to put undue pressure on the contacts when making adjustments. There was a minor error on the parts diagram as the the tension studs, marked ‘I’, were listed as tension nuts. One element that was completely unexplained was which way round to wire the contacts. The ‘standard’ seems to be for the left paddle and tip of the plug to do dots, so I put the red wire to that and to the tip of the plug. The blue wire then went to the right paddle and the ring of the plug. I assume you can work out where the green wire went!

Adjusting the lever position

The paddles operate machined lever arms with a 90 degree bend in them, so the contacts are to left and right of the block assembly. The knurled contact adjustment screws have a fine thread and there are knurled locknuts, so making and keeping adjustments is easy. Two tension studs pass through the block and do two things – their position sets the backstop for the arms and thus the angle the paddles sit at – and the tension springs sit on them, with adjustment nuts at the front, by the rear fingerpiece screws. The position of the tension studs is set early on in construction and they are held in place by two tiny grub screws that go down into the block.

The finished paddle

I wasn’t timing it but I’m pretty sure the mechanics of the kit took me less than an hour to put together. It took almost as long to terminate the cable! I’d decided to use a 3.5mm jack plug and wired the paddle end first. Unfortunately I’d inadvertantly left myself the ‘wrong’ end of the cable for the jack plug as the contacts didn’t line up with the way the cores were positioned in the cable. All solved in minutes but very fiddly – I won’t make the same mistake again!

I’m obviously not an experienced CW operator so don’t have much experience with the paddle but it is definitely better than the UniHam. I’m still making too many mistakes but have the keyer set to 20 wpm so the paddle definitely isn’t holding me back. It has made me realise I was developing a ‘banging’ style of keying, particularly for ‘P’s, ‘X’s and some punctuation characters, so I’m trying different gap and tension settings. The one minor disadvantage is that, despite its decent weight, the rubber feet don’t have as good a grip on my desk as the neoprene strips on the base of the UniHam. Consequently the key can move a bit on occasion. It seems to be less and less of an issue as I tone the ‘banging’ down. Should it prove necessary I can always 3D print a base that I can put neoprene tape on (there’s a design on Thingiverse).

My kit cost £132 including VAT and shipping from Germany pre-Brexit. I had excellent service from Kent. I emailed to check availability and Andrea emailed back that evening to say one could be shipped by the weekend if ordered soon. I did so and it arrived on the Monday. Would I buy another one? I’m tempted already…

* But I have been known to buy Ikea Helmer drawer units just so I can have the fun of putting them together

Update May 2021

I had some problems with my paddle, which appeared to be caused by intermittent paddle contacts. In fact it turned out that it was a combination of three issues:

• The contacts on the arms are held in place by screws, so there is a dip in the middle of the contact. I’d inadvertently set my paddle up so the pillar contacts touched them right by the dip. Rotating the contact pillars slightly solved that.
• I was using a cheap 3.5mm jack extension lead and the extra resistance wasn’t helping.
• Additionally I discovered the rig I was using wasn’t very good at debouncing contact closures.

73

Mike
G4RAA