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Miss Mosquita, the German QRPer female QRP Transceiver

(so small - so spicy - it must be a Lady)

NEW! After 3 years in a pillbox, Mosquita got a new enclosure

New Mosquita-3:

one Xtal more in the IF Filter,

new IF 4,9152 MHz

PA with modern Mitsubishi RRD16HHF1

Download the new manual (english)

Mosquita is a typical "Made in Old Europe" Kit-Design.

What does this mean?

European HAMs know it, US HAMs may have heard about it: Short wave in Europe is a strange thing. Hundreds of high power BC stations cause extrem high signal levels even at smaller antennas in Europe. At winter evenings it is quite normal that a Receiver must handle up to 300mV and more. That´s the reason that typical European Receivers are using a selectiv frontend.
"Made in Europe" means: Technical better solutions determine the design. We prefer less compromizes even if this makes it more difficult to sell the kits because it gets a little more expensive uneasier to build the kit.
E.G. Mosquita is offering a full 5 Watt PA using an oversized 2SC1969 transistor. This helps during portable operation where very often the antennas are not so well matched. Mosquita is probably the smallest kit offering a fully functionally AGC with > 90dB dynamic. To get this, we had to use some extra parts on the small footprint - this makes it more complicated to assemble the kit, but we are sure, a real HAM who wants to get the best rig for portable use will be able to handle it.

What do you get if have built Miss Mosquita?

A fully equipped 40 m CW Transceiver ( DDS Versions of Mosquita will be available for 80m 40, 30, 20m starting June 2006 )

single conversion superhet with a 6 pole Cohn filter

filter bandwith of some 500 Hz (40 m version)

VFO tunable over the entire CW segment

Sensitivity about 0.4 µV (By design reduced because the < 0,1 uV of the prototypes is ways to much due to Antenna noise at 40m of abt 0,8 uV

AGC on the IF, more than 90 dB of dynamic range

Adjustable transmitter output of up to 5 W on 40 meters

Efficiency of PA of more than 70%

Soft keying of the transmitter

Monitor side tone facility

Working voltage of 10-14 Volts

Working current, RX 30 mA, TX+RX some 380 mA. Pout= 2W at E=12.5 Volts.

Optional RIT

Starting in April 2006 Mosquita got a new, more functionally enclosure. It´s made from a very stable 100mm x 100mm x 25mm Aluminia Profile and offers space for usable optional Addons like the Universal RIT, a PK4 keyer, the Micro SWR Meter, a PLL CW Indicator and even a Digital readout.
The Basic Mosquita now contains: Double sided PCB, all parts, enclosure, 10 turn pot with mechanical Readout, all Jacks.

Ready made coils for Mosquita:
Of course in our opinion winding coils is not a real problem. But as we heard in several Discussion from HAMs all over the world, the only reason NOT to build an own rig is the coil issue. So we tried, if it is possible to help this guys and we found two ways:

We optimized the description how to wind coils by edding some pictures and by introducing the powerfull "Coil Winding Machine" of Ingo, DK3RED. This machine costs nothing, but it helps
We offer a handmade set of coils, each tested in a working Mosquita.

The History of Miss Mosquita

The tries to minimize QRP Transceivers like Pixie, FOXX, Rockmite and others have driven us to design our own project. Crazy as we are, we planned from the very beginning to beat all other designs by including the quality of a much bigger transceiver into the same pill box the others use without limitations.
It should be:
Superhet istead of direct conversion.

VFO instead of VXO
Full AGC
PA with full gallon 5 Watt.

During the discussion process we followed 3 different design ideas but at the end we came out with a downsized sparrow transceiver. We named it Miss Mosquita because it was such a hot little thing as only a girl can be. Its called Mosquita, because a Mosquito allways is the winner even in the most worst PileUp

Here you see some Pictures of the first prototype. BTW, the hand you see at the left picture is the hand of the genious German QRP Club Designer Peter Solf, DK1HE who designed most of the German Club kits like Black Forest Transceiver, Hohentwiel 2m SSB/CW, Tramp-8 CW Transceiver and a lot more.

klick on the pictures to enlarge them if you want.

Miss Mosquita. See the XTalfilter upper right corner

While building the prototypes we learned, that Miss Mosquitas VFO gots instable if power was greater 2 Watt output. So we built a second variation into an encosure made from PCB material. This gave us the chance to use a heat sink. Also we now had space for an iambic keyer PK3, a micro VSWR Meter and a 10 turn Pot . This has been covered by several kit builders with excellent results.

upper left the 50 Ohm head of the SWR Meterupper left the 50 Ohm head of the SWR Meter

Left side key, earphone, SWR red/green meter.

Middle and right side: CW-Speed, PK3 Menue and frequency adjust

Early in 2006 we decided to give Mosquita an own, more professional enclose because she is worth to get it

For direct access to the QRP-Shop Mosquita page click here

Click on the button to load the english PDF manual Click on the button to load the english PDF manual