MKARS80 Transceiver kit

The MAKRS80 is a QRP transceiver designed for use for use on the 80M band, the circuit was developed from the BITX20 designed by Ashhar Farhan. Although simple in design perceived performance is as good as a commercial transceiver.

Main changes from Ashhar's original design are the inclusion of a frequency counter and a Huff and Puff frequency stabiliser; this circuit will help keep the VFO tuned to the same frequency for long periods without any "drift".

As seen in the photo to the left, all components are mounted on to a single high quality PCB making construction relatively straight forward. The only "wiring" needed is short pieces of wire to connect the potentiometers to the PCB.

To assist with construction there is a comprehensive manual that can be downloaded from this page, also available for download are a drilling template and front panel overlay.

Why not joint the MKARS80 support group?


Features
  • Full 80M LSB coverage (3.5 - 3.8MHz)

  • ~ 5 Watts output power

  • Single conversion superhet with 4 pole crystal filter

  • Frequency display with "Huff and Puff" circuit for stabilisation

  • Modulation monitor - helps stop over modulation

  • Volt meter - useful for battery operation

  • Reverse polarity protection (fuse protected)

 

Photo showing a typical finished MKARS80, note that the knobs supplied as an option are all black without the aluminium inserts.


Downloads

MKARS80 construction manual version 1.3
Latest version for currently supplied kits.

MKARS80 construction manual version 1.3 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.

Panel overlay (Use for undrilled box only)
Print and laminate as a front panel, alternatively use the mirrored overlay below.

Mirrored overlay (Use for undrilled box only)
Print on acetate and use as a front panel, the print will then be on the reverse side so it doesn't become scratched

Panel overlay for use with ready drilled box
Print and laminate as a front panel.

Hires Schematic (JPEG)
Bold Text Schematic (PDF)
Two different formats of schematic which will be easier to read than that in the manual

MKARS80 PIC firmware
Download and modify for your own use, perhaps the easiest modification is to change the startup screen to include your own callsign. This will require the installation of MPLAB, download from the Microchip website free of charge.

VFO stability modification
Makes a significant improvement to the VFO stability on early transceivers, this was incorporated into the kit from Dec 2008


Old data

MKARS80 construction manual V1.0
Only for use with kit version V1.0, this has minor component differences so don't use with other versions

MKARS80 construction manual V1.2
For kit version V1.1 and V1.2

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


Kit Contents

The kit contains all PCB mounted components including display, connectors and a ready programmed micro. The builder will need to provide a loudspeaker (3-32 Ohms) and an electret microphone; a dynamic type can be used if the bias resistor (R17) is removed or a series capacitor is installed between microphone and transceiver.

Knobs are supplied with the boxed kit as standard, they may be ordered as an option for the kit sold without a box.

Neither kit comes with an overlay, you can either design a personal version or print off one of the options above.


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, postal order or direct transfer which attract a small discount - please email me for details.

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


 


Posted to the UK

MKARS80 kit supplied with an aluminium case (apertures are laser cut) and knobs.

 

Out of stock, more due 18th December

£72.00

 


Posted to European continent (EC, Russia, Norway etc.

£74.00

 

International post (USA, Canada, Indonesia etc.)

£76.00


 

MKARS80 kit supplied without any case or knobs.

 

 

Out of stock, more due 18th December

Posted to the UK

£61.00

Posted to European continent (EC, Russia, Norway etc.

 

£63.00

 

International post (USA, Canada, Indonesia etc.)

£65.00


Options

Note options can only be purchased with a kit

 

Knobs kit - large, medium and small knobs with 4 rubber feet.

NOTE Knobs are now included with the cased kit.

£2.00


Connector kit - Includes BNC plug, 3.5mm stereo jack, 3.5mm mono jack and 2.1mm DC plug

 

£2.50