CW Adapter kit

This unit has been designed to fit "in-line" with the MKARS80 to provide a CW function without modification to the MKARS80 itself.

The circuit generates CW by inserting a tone into the microphone input; to avoid harmonics of the tone appearing in the TX spectra the design incorporates two stages of bandpass filtering in the TX audio path; when used with a correctly adjusted MKARS80 unwanted spurious signals are > 40dB below the wanted carrier. In most instances these artifacts will be masked by band noise.

An identical filter is used in the receive path giving quite a narrow receive bandwidth of about 200Hz. This filter is switchable.

A break off PCB carries an Iambic keyer with memory function, the circuit and microcontroller code were designed by Wolfgang DL4YHF and are reproduced here with his permission. His website carries full information.

Features

• Adds a CW function to simple SSB transceivers
• Useful for CW sending practice
• Shaped keying
• Built in side tone (Approx. 800Hz)
• Adjustable side-tone level, hang time and drive level
• Switchable narrow receive filter
• Reverse polarity protection (fuse protected)
• Optional Iambic memory keyer - by permission from DL4YHF
  

Downloads

CW Adapter construction manual
Version 2.0 in pdf format - Latest version for currently supplied kits.

CW Adapter construction manual in Spanish
Thanks to Jon EA2SN for the translation.

Drilling template
Printout with Adobe Acrobat reader, set paper size set to A4 and page scaling set to "none". Stick onto case as described in construction manual and use as a drilling template for the holes and cutout.

To follow (PDF)
Large type format which is easier to read than that in the manual

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NOTE: Kit version can be found on lists in all component bags

Kit Contents

The kit contains all PCB mounted components including connectors, the builder will need to provide a suitable case. The CW adapter will fit the case used by the MKARS80, the keyer however will have to be housed separately. The case is listed as an option.

How to order

Payment can be accepted by PayPal, direct bank transfer, Western Union or by a Sterling cheque from a UK bank. For details on payment by Western Union or direct transfer please contact us for our banking details.

Probably the easiest way to pay is by PayPal, below are a series of "buttons" - select the appropriate one(s) and when finished click "View Cart", once payment has been made you should get an e-mail from PayPal confirming payment - we will send you an e-mail (to your Paypal e-mail address) normally within 12 hours advising on delivery etc.

UK orders can be made by cheque or postal order, HERE is an order form with up-to-date pricing for UK delivery.

Note that PayPal prices include postage, not included are any import taxes which may be charged by your customs (non EC countries); YOU are responsible for these. We can not enter "sample" or "gift" in the customs form so please don't ask

CW adapter supplied without a case