When I Am Not Working…

Outside of my professional life, my interests are classic cars and motorbikes, and music. My ‘daily driver’ is a Jaguar Mk2, 1966, silver in colour with a red leather interior. I have owned this car since 1999, and over the last 17 years it has been repaired, restored, repaired etc as is the way with old cars. We even used it for our wedding in 2001. Although I love originality and patina, I still want a reliable car so various repairs modifications have been completed over the years to ensure good performance in modern road conditions. A list of some is below:

Full stainless exhaust system.
Modified XJ6 power steering rack to replace leaky Burman steering box.
Polyvinyl suspension bushes.
Gas shock absorbers
Led lamps & bulbs courtesy of Duncan Rickards of www.classiccarleds.co.uk

Rebuilt transmission by Graham Whitehouse Autos.
Rebuilt engine by Merseyside Engine Parts.
Electronic ignition.
Magnecor ignition leads.
Spal auxiliary cooling fan and Pro Alloy inline fan switch
Exhaust manifolds ceramic coated by Zircotec

And the list goes on.

One thing I haven’t done however is convert the car to negative earth electrics. This is for several reasons, not least the power steering pump is driven by the dynamo, and I like the original Smiths Radiomobile radio!

This creates two problems. One is the drain on the modest dynamo output by lights and other accessories, and the other is music options. The LED lamps has sorted the drain or draw issues because they take less than 1/10th the draw of normal bulbs, and will likely last the life of the car (and me)!

The second seemed a problem, until now. Latest addition is a ‘Redirad™.

I have fitted a RediRad™ to my ‘positive earth’ 1966 classic car, and I am seriously impressed now with the sound from the original Smiths Radiomobile radio, and the phone ‘hands free’ functionality is a real bonus.

No Modification To The Existing Radio.
Maintains Original Appearance.
A Reliable Auxiliary-Input Solution For Classic or Modern Car Radios.
Solid State Construction, Made In The USA.RediRad-AMN-Small

Models available are:
Positive Earth ‘AM’ (Medium Wave)
Negative Earth ‘AM’ (Medium Wave)
Negative Earth ‘FM’

I am very pleased with the RediRad™, and I didn’t know the old radio in my car could sound as good as it now does.  I am so impressed I have arranged direct with the manufacturer, to offer units to members of classic car clubs in the UK at a discounted fully inclusive cost, and they will be sent by ‘Royal Mail Signed For’ from my UK address, so no hanging around for Customs clearance etc. like I had to.

Price is £110.00 inclusive of all shipping, import charges, VAT and ‘Royal Mail Signed For’ delivery to a UK address.

Usual cost to UK buyers buying from the manufacturer or other outlets in the US end up paying import charges, shipping and delivery and the total adds up to around £130.00 per unit, so a saving of £20, or 15%.

The unit is designed for the very widely used ‘Motorola’ type aerial lead connectors, but adaptors are widely available for around £5-£10 online if your car or radio is fitted with a different set up.

There is an online video showing the installation process in a 1980’s BMW. Again, the speech is American but most should be able to cope. Search for ‘RediRad™ BMW Installation’ on a well-known video hosting site.

The only difficulty if there is one, and this will vary from car to car, is the routing of wires etc.

Unplug radio antenna from radio.
Plug RediRad™ into Radio antenna socket.
Plug Antenna lead into RediRad™.
Electrical connection is one to an ignition controlled power supply, and one to earth.

That’s it, and you are left with a lead (with a 3.5mm jack) to plug into whatever you would like to play. I have placed the unit in my car behind the facia just on top of the radio itself, secured with cable ties (again included in the pack). The only visible sign is when I draw the auxiliary-in lead from it’s hiding in place in the dash cubby hole.  Connect up the player, and tune in on the radio to 1000KHz (the ‘10’ position on some radios, or 300 metres MW.) I have tried an mp3 player, Nokia smartphone and an iphone, and all work fine. (The negative earth FM version tunes to 91.1).

Available for positive & negative earth cars, 6v or 12v, AM (LW/MW) or FM. The sound quality is as good as your radio amp & speaker can muster, and I like the tone of modern music on my cars single 6” speaker. Not just for music; plug in your smartphone and you have effectively got a hands free installation, (and in my car the unused ashtray is the perfect cradle for a phone) with the inbound call being heard through the radio speaker(s), as you would with a modern hands free system, and if you want to use the satnav on a phone, again, it will play through the radio. Tip; Don’t have the volume on your input device on maximum, between half and three quarters is best, it will vary from device to device, and then control radio volume as normal.

Please carefully read the information below, I will answer any questions I can, or get an answer from the manufacturer for you, or see for yourself at


and download a pdf version of a manual.

Please note this is not my day job, but an extension of my interest, ownership and enjoyment of classic cars and I have a very full time occupation already.

Order by sending an email to me john@johncartlidge.com

I require an email order as you will be sent an emailed ‘paypal’ invoice (you do not need to have a ‘paypal’ account to pay) and to avoid errors or misunderstandings I request a detailed written emailed order as follows:

Name of Car Club?
Make & Model of Car?
Make & Model of Radio?
6 or 12 volt?
AM (LW/MW) or FM version required?
Positive or Negative Earth? (This last point only applies to AM (LW/MW) versions.)

Optional Extras: Please tell me in your email if you require any of these items:

‘Royal Mail Next Day Insured’. (+£5.00)

‘Period’ 3 terminal single pole double throw switch. (+£5.00)
See notes below about 2 or 3 position ignition switches to see if you might want one of these.

‘Piggy Back’ 1/4″ (6.35mm) Receptacle Spade Connectors £0.50 Each.

Orders will generally be posted next working day after receipt of cleared funds. If sold out pending fresh stock from the US, I will not invoice you until stock is replenished and will let you know when to expect your invoice.

I can take phone enquiries, but I am often away from my office (in my car…) so email would be more efficient, and I don’t want to rack up huge phone bills returning calls for what is just an extension to my hobby.

Online from various US sources they can be bought for around $100.00, but shipping and import charges (including VAT) mean the total price paid by UK buyers is around £130.00, plus the delays waiting on Customs etc. I have seen cheaper variants from China (although western ‘branded’) but these don’t have the track record of the RediRad™.


Electrical Draw.
The FM model ‘idles’ at around 7 milliamps (0.007 A) and draws about 40 milliamps (0.040) in RediRad™ mode.

AM (LW/MW) models ‘idle’ at around 25 milliamps (0.025 A) and draw about 150 milliamps (0.150 A) from a 12V system in RediRad™ mode.

Two position or three position ignition switch.
On most cars since the 1970’s, the ignition switch where fitted has three positions. 1.Off, 2. Accessory or Battery, 3. Ignition, with a sprung fourth position or starter button to start the engine. The RediRad™ is connected to the Accessory or Battery position, or another source energised by this position on the switch. However, many older cars, including my, have only a two position switch; 1. Off, 2. Ignition and then a sprung third position to start, or a starter button. In these cases the RediRad™ is connected to a switched supply. On my car, I chose to ‘piggy back’ the supply to the fan heater switch but it could be any ‘clean’ fused supply. By clean, I mean not on the ignition, fuel pump circuit or indicators circuits.

Types of Ignition Switch: IMPORTANT.
Owners of cars with three-position ignition can therefore use their radio and RediRad™ whilst parked, with the key in the Accessory or Battery position, as they might with the existing radio. Owners of cars with two-position ignition cannot, as to have the ignition on without the engine running means the fuel pump (if electric) will be running, and the coil and ignition circuit will get hot with high risk of failure. I modified the installation so that I could use the system whilst parked. (The radio was always directly wired on such cars). I have fitted a discrete 3 terminal single pole double throw switch. (Mine is concealed in glove box.) This is wired as follows:

Terminal 1. Power in – Ignition controlled from ignition switch or fuse controlled circuit. In my case the heater fan switch.

Terminal 2. Output to RediRad™

Terminal 3. Power in – permanent supply (piggybacked off cigar lighter in my case.

Default position will be power from terminal 1, but if required, I can throw the switch and use whilst parked without risk of damaging ignition circuit components or fuel pump running.

Positive Earth Applications Only: Three Very Important Notes.

1. Input Device Chargers.
Almost universally, modern devices and in car chargers are for negative earth only. There are workarounds but they are unreliable from what I have read so it is far far safer to just do not charge a negative earth device (e.g. iphone) in a positive earth car. CHARGE AT HOME, USE SAFELY.

2. Metal Cased Input Devices.
For the reason linked to the charging issue, if your input has any external metal casing, ensure it does not earth itself against car metalwork; use a NONCONDUCTIVE case, or place in a NONCONDUCTIVE location e.g. plastic or upholstered.

3. When Not In Use.
Use the protective cap supplied for the aux lead so that when the RediRad™ is energised but not in use, it cannot earth itself to car metalwork.

I hope this covers all the bases, but I will answer any questions I can, or get an answer from the manufacturer for you.

All the best, now, where are my car keys…