Heathkit HW-9 Kit

A complete kit of parts for the Heathkit HW-9 became available on Ebay just recently and the opportunity to build such a rig from scratch was just too much to overlook.

The Heathkit HW-9 was the third in the series of QRP transceivers and was produced between 1984 - 1991. It has a very good superhet receiver and an optional WARC bands kit and therefore covered all bands between 80 and 10 metres with slightly higher power output than its predecessor.

The HW-9 is shown in the picture below 

Specifications for the HW-9

Transmitter

RF output Power                   CW - 4 watts on all bands except 3 watts on 10 metres

Frequency Offset                  700 Hz Lower on all bands

Harmonic Radiation                  - 30dB minimum at rated output

Spurious Radiation                   - 40 dB minimum at rated output

CW Sidetone                             700 Hz to speaker or headphones O/P level adjustable.

Receiver 

Senstivity                                   < .3uV for 10dB S+NN. < .2uV for readable signal.

Selectivity, CW Audio Filter    Narrow - 250 Hz max at 6dB

                                                   Wide - 1 KHz max at 6dB

Passband Centre Frequency    700 Hz approx

Dynamic Range                        85 dB in narrow filter mode

Image rejection                         60 dB minimum

IF rejection                               60 dB minimum

Internally generated In-Band Spurious   Typically belwow 2 uV except at 3.695, 7.166, 10.150, 14.041

                                                                                                                          14.083, 21.195, 28.089 and 

                                                                                                                          29.093 MHz

RIT                                             +/- 1 KHz

Here is the picture of the bits and pieces purchased for building the Heathkit HW-9 from scratch.

As the parts were taken out of the original box, it has taken time to identify which pack of components, shown in the brown bags, pertains to which section of the manual. They have now been identified so the build will commence shortly. It would appear that I have to acquire the optional pack of components to make this tranceiver work on the WARC bands but I suspect that I can manage without them for a while!

There are three parts to the build in the form of the Oscillator Board, the T/R Circuit Board and the Chassis.

The PCB's are shown below

More to follow .............................

Heathkit HW-8

I am not an impulse buyer by nature but this little gem just caught my eye whilst browsing across Ebay. It was described as having no modifications and in excellent condition and came with the matching HWA-7-1 power supply.

Taking a look at the manual that came with this rig, it would appear that it was carefully constructed by its former owner as each stage of construction had been ticked. 

A lengthy check inside showed that no modifications had been done. The HWA-7-1 PSU was in working order but has to be modified to 240 volt operation but it only involves removing 2 links on the transformer and adding one link.

History

The HW-8 was the second in the series of QRP HF CW rigs produced by Heathkit between 1976 - 1983. The direct conversion receiver was an improvement over the former HW-7 model and covered 80, 40, 20 and 15 metres. The HW-8 used to retail for around $129 but they can fetch a very good price on E-bay as they are much sought after and very popular amongst the QRP fraternity.

Specifications 

Transmitter

DC power input                              3.5 watts

          80 metres                              3.0 watts

          40 metres                              3.0 watts

          20 metres                              2.5 watts

Frequency Control                        Built in VFO

Sidetone                                         Built in with adjustable volume

Spurious and harmonic Levels     At least 35dB down

Receiver

Receiver Type   Direct Conversion with RF amplifier, balanced product detector and active Audio filter

Sensitivity         1 microvolt for 10dB S+N. 0.2uV provides a readable signal.

Selectivity         Wide - 750 Hz @ 6dB down

                           Narrow - 375 Hz @ 6dB down

Passband Centre Frequency      750 Hz

Reception                                     CW

Audio O/P                                   1000 ohms nominal

The HW-8 has been the subject of many articles providing modifications and improvements to the circuity and of course a special Yahoo Group for owners of this excellent radio. The HW-8 handbook is available which covers many modifications to the HW-7, HW-8, and HW-9. tranceivers.

It just remains to take tim to brush up on the CW and improve the speed to make a dent in the airwaves.