The HF all-band transceiver

HF all-band transceiver

It is a story about 10 years ago. HW-9 of Heathkit was displayed in the show window of the radio shop in Akihabara which I sometimes go to. Heathkit was the "flower of the high peak" for a long time in Japan. In other words, it was very expensive. At least, when I was a student, I couldn't buy it at all. I always only saw Heathkit put in the show window.

It passed for about several years, and I got a job. I became just a little richer than me in the school days by the salary and the bonus. In addition, the imports price decreased by a strong yen's proceeding. Then, I decided that I bought Heathkit at last.

However, I went to the usual store, and faced a very shocking situation!! The salesclerk of that store declared "There is no Heathkit any more." coldly. I was shocked at the explanation of the salesclerk of "The Heathkit company withdrew from the radio kits."

"However, it is put on the show window. Won't you sell that?" I asked after 1 breathing.
"That can't be used. That was taken back in the store, because a purchaser failed in assembling." the salesclerk said.
"I don't mind it." I said , and asked about the price.
"Think that it is scrap iron." the salesclerk reminded me, and told me "Well, a price is 10,000 yen (about 90 dollars)."

I bought the SP-99 of Heathkit displayed together for 3,000 yen (about 27 dollars), too, and I left a store. I did like this, and I could take HW-9 in my hand at last. I shouted "It is lucky!" stealthily with walking.

After I came back to the house, I opened the case of HW-9, and investigated the state of that. Then, the wiring was very cruel condition. I removed all wiring, and checked two circuit boards. The error of the way of installing a parts were found one after another, too. It may have taken about one week to repair all of these. My HW-9 came to work somehow as a result of the repair. But, frequency doesn't change smoothly because the VFO mechanism warps physically. Because it is a machine for CW, the variable range of the frequency is small, too. I had discontent to these, and decided big remodeling.

Then, it took seven years, and big remodeling was completed. It was a really different machine more than big remodeling. Only the appearance is with being very similar to HW-9. But, VFO is digital indication. Therefore, the person who saw it well will notice that it is different from HW-9. Incidentally, I displayed this radio in the ham fair meeting place in 1999. It is said that Ukrainian who saw this wanted this very much. However, because I like this, I hand it over to no one.

Local oscillator board

Main board

Characteristics and composition

Frequency coverage : 3.5MHz-28MHz 8band
Mode : SSB/CW
TX-final : 2SC1947
Power output : 1W
RX-RF amp : 2SK125*2(Grounded Gates)
1stIF : 48.7265MHz
TX/RX 1st mixer : MiniCircuit MCL-1
RX 1st IF amp : MC1350P
2ndIF : 11.2735MHz
TX/RX 2nd mixer : MiniCircuit MCL-1
RX-2nd IF : MC1350P*2

Circuit schematics

Original documentation and schematic: http://www06.u-page.so-net.ne.jp/ga2/semba/e_toppage.htm