Delkim News

“Necessity is the mother of invention”

By March 15, 2017 No Comments


Del Romang the MD and Chairman of Delkim gives his account of 25 years of vibration indication and the development and success of our own range of bite alarms.

Del with a 60's carp

Del with a 60’s carp

Del with a 70’s carp (note the hair!)

“I don’t know where the inventor in me came from.  I had absolutely no electronics knowledge whatsoever back then and all I ever wanted to do was go fishing.  I could never have imagined even in my wildest dreams that I would eventually end up inventing an entirely new line movement sensing system and making my own unique award winning bite alarms.

In the very early days before any specialist tackle was available, we were having to adapt bits of general tackle for us Carp anglers to use.  The only really specialist gear that existed then was the Richard Walker MkIV split cane Carp rod and the Heron bite alarm.  We even modified low water Salmon hooks as no hooks then existed that were up to the job.  That all seems light years away now and to younger angler almost unbelievable!  Up until the late 70’s my only “inventions” were a couple of songs for my rock band plus a unique production system that I had devised in the shoe factory where I was working in the office at the time.  I was fully aware that the available bite alarms were simply not good enough from a reliability, battery life and sensitivity point of view.  I won’t go into the details of the infamous Delkim Optonic Conversion saga here as that would take another complete article of its own.  Suffice to say I simply wanted to make my own bite alarms using the experience that I had gained.

How Delkim made its name in the early years

The original idea for the Delkim Vibration Sensing System actually came to me in the middle of the night back in about 1983, allegedly in a dream.  I say allegedly because it seems a lifetime ago now and at nearly 72 years my old memory ain’t what it used to be.  I can, however, remember vividly what happened when I drew a short length of nylon line over the stylus of my hi-fi record turntable.  There was a horrible scraping noise from my speakers but when I speeded up the movement the resulting sound swished upwards in tone.  It was a Eureka moment.  I had been racking my brains to find an alternative method of detecting the speed of line movement from using a roller and I realised that what I had just done had exciting potential.  Straight away I set about patenting my idea and commenced on my early development attempts.  What I did not realise at the time is that I had not just discovered an alternative method, I had discovered something with the potential to take Delkim electronic bite detection to another level altogether.

My record player stylus was essentially a vibration detector and I found out that they were available in piezo ceramic form.  Piezoelectricity was discovered by Pierre Curie whose eventual wife Marie Curie was even more famous for her work on radiation, but I digress.  In very crude terms certain crystals emit a voltage when vibrated as well as oscillating themselves when connected to a suitable electronic drive circuit.  The first practical prototype was simply a piece of gold wire soldered to a piezo transducer similar to what we now use as speakers in our Delkims.  The piezo transducer was used as a vibration detector rather than a sounder.  The line ran in a V that was bent into the gold wire which vibrated the piezo transducer.  When the line moved it set up vibrations and the  connected electronic circuit plus speaker gave beeps.  The first crude prototype was tested at Hawkstone Park Lake in Shropshire in the presence of two old friends of mine, Pete Barker and Pete Dumbill, sadly both now deceased and my son Lee who was only about 10 years old at the time.  I was fishing off a wooden platform in Monastery Bay and the prototype was so sensitive that every time I moved the bloody thing went beep.  I recall my words at the time that it could “pick up a Carp farting 100 yards away”.  Little did I know how difficult it was going to be to control the damn thing.  With my very limited resources at the time I was working with clever hobby electronics enthusiasts rather than piezo experts so it took a long time to fully develop a viable bite alarm with several false starts along the way.

The heart of every Delkim alarm. The vibration sensor.

The next real big landmark was a “black box” version which was actually controllable that I tested at Cromwell Lakes in Nottinghamshire and it worked very well.  Unfortunately I don’t have the actual prototype in my archive which is a real shame.  Having no money for mould tools at the time I came up with a plan to encase the circuit and sensor inside one of my infamous Delkim Optonic Conversions.  This had advantages.  I could test it without anyone knowing what I was doing and it saved the cost of mould tools at this early stage until it had been fully tested.  There was a lot of fine tuning to be done and one of the main issues was controllability.  At the time I could not find a single sensitivity range to cover all situations.  It was either too sensitive or not sensitive enough.  I had to be sure, particularly in windy conditions, that I could “dial out” false indications yet still retain a high level of sensitivity.  Eventually I asked for a high and a low sensitivity range which actually became the perfect solution covering everything that I could throw at it.  In order to test it in windy conditions I fished at Naseby Reservoir in Northamptonshire which we would now know as a “runs water” that was quite open and subject to the wind.  Fishing off the dam wall I was getting at least 10 small Carp a day in the winter which was the perfect way to test bite alarms.  One run a week is not a good test.  It was at Naseby that I started to get some strange “false indications” that I subsequently found were no such thing.  They were actually “pre indications” of a full blown run.  A couple of beeps out of the blue that did not coincide with a gust of wind were often followed by a full blown run with the Delkim warbling away in its distinctive alternating tone.  My field testers were actually reporting the same thing.  Whether it was the rigs that we were using at the time I don’t know but it began to feel as if my alarms had a sixth sense.  It is a phenomenon that has subsequently set Delkims apart from other bite alarms and is invaluable when fishing close to snags where a couple of beeps out of the blue can put the angler on red alert of an impending run.

The original Delkim alarm with vibration sensing

I am often asked why the famous Delkim warble?  Well it was another matter of necessity.  When the internal speaker was turned up full the vibrations from the speaker would resonate through the case and in the air to cause howl around or feedback when the sensitivity was turned up.  This is something that I was aware of from my days in rock bands where feedback from the microphones was either a nuisance or it could cause nice controlled sustain from my Gibson Les Paul but that’s another story.  I actually came up with the compromise solution not the electronics experts.  At the time a full blooded run on an Optonic was often referred to as a screamer or one toner and it was the continuous tone that we were using that was causing the feedback.  The whiz kids told me that there needed to be gaps between the beeps where we could sample the signal and it was the only way around the problem.  The trouble was that with gaps the bloody thing sounded like a machine gun when the beeps got faster.  There appeared to be no answer to the problem.  But this is where my lateral thinking came in handy.  What does the screamer indicate?  That there is a fast run.  How could we indicate this and have gaps between the beeps?  What about if when the beeps get to a certain rate could we have alternating tones to indicate a fast run yet retain the sampling gaps?  Bingo.  Problem solved and yet another patent application.

Kim Donaldson the co-founder of Delkim

We were now making progress and finally in 1992 the very first Delkim Standard Bite alarms hit the market and were an instant success.  The rest is history including the virtually annual awards for the Delkim Tx-i as Best Bite Alarm.  The 25 years of Delkim Vibration Sensing in 2017 is a landmark that I am justifiably proud of.  It has been a been a life changer for me and our families but sadly two major contributors to the Delkim success story are sadly no longer with us but they definitely deserve a mention.  Kim Donaldson who was a close angling buddy of mine whose name appears on every Delkim left us with his boots on suddenly in 2001.  Also my first wife Bev who was so supportive died in 1998.  I actually got remarried to Bev’s best friend Carol Carrington in 2001 who was our bridesmaid first time around.  The circle of coincidence was completed.  What a funny old world.  The merging of our two families has eventually led to all seven family members joining Delkim progressively over the last fifteen years as our success grew.  My son, Lee has been involved the longest apart from myself and as I said earlier was even witness to the embryo stages of development a very long time ago.  Each individual member of the family makes their own invaluable contribution towards our success which is a pretty unique situation to go with our unique award winning products.

Del still fishes as much a possible

Let’s see what the next 25 years hold for the Delkim Vibration System which has a lot still up its sleeve.  Watch this space.”


About fenjaguar09