23 February 2009

Two new US States on 30m

Did not have much energy and time this weekend for the radio, but a late Sunday night session brought in Vermont and Tennessee. The latter had a KG4 callsign, which I initially located in Guantanamo Bay. Never mind.

I was pretty tired and my CW copying skills were down to the bottom. I remembered what Hans UPL wrote me when my first child was born: sleep deprivation equals lousy CW op.

I need to build an interface to a tape recorder for my FT-817 so I can record contacts and enjoy them afterwards.

In the meantime I have drilled the shack wall to let the coax in. Antenna is still the horizontal base loaded monopole.

16 February 2009

30m update

Two new countries on my 2009 30m CW QRP challenge this weekend. The band was incredibly open on Saturday night, with many stations chasing K5 DX-pedition not minding a normal QSO. Was not so lucky on Sunday night nor Monday morning.

Statistics so far: 23 DXCC entries, 4 continents.

CU next weekend on 30m!

11 February 2009

Replacing your car radio

The cheap radio I got with an used car broke. Actually a small hook holding the detachable front panel broke, so it became useless. Not a bad news since the FM receiver was extremely poor, it played only original CDs and had a PTO tuning mechanism begging for inspection (see previous posts).
I had kept aside an old MW/FM/cassette device from 90's, that is now approximately 14 years old. It had a very good receiver, so it was time to put it back into service!

First thing to know about car radios: they have a standard outer size. So, even if they probably have different hooking mechanism to the supporting frame, they fit interchangeably. I also discovered that mine was only inserted into an existing frame, and the radio body could be pulled out with a simple movement.

Connections were worrying me. Almost two decades had passed, both for car audio industry and car manufacturers. Moreover the two cars were of different makers (Rover vs FIAT).

The antenna connector is the same. I don't know the name of that sort of plug, but I was happy with it.

Rear panel connections looked very similar indeed! Good news: those connectors are standardized, ISO 10487! Moreover both devices carried a label showing cables and their functions, so I could match them side by side and make sure no rewiring was needed.

Newer device had only A and B parts (powering and loudspeakers respectively), while older had also C. Since "C" connector is for extensions, not used in my case.

So I just plugged the antenna and the ISO connector ... et voilĂ  ... the job was done while waiting for a couple of semaphores to turn green.

You may try this at home only if you understand the risks of playing around high capacity batteries. Take your time to make sure both connections are wired exactly the same!

I am now enjoying medium wave reception in a small city car, whose emissions render unpleasant the band:
  • below 1000 kHz, with ignition noise on weak signals
  • during rain with windscreen wiper motors noise
  • in Summer with A/C pump noise
Have fun.

09 February 2009

Crossing the Atlantic, QRP

On Saturday Feb 7th at night I got a 559 report from Maryland, USA. This is the first transatlantic QRP QSO on my homebrew balcony antenna. 30m CW, of course. TU Bill, good ears!

On Sunday night I worked Russia and Ukraine, with good signals. I was surprised to find the band so crowded after two weeks of QRT. 2xQRP was possible too.

03 February 2009

FT817 keypad - PTT for the lazy and Timed Tuning

While developing a custom firmware for the keypad, I came up with three more possible functions.

The first is a review of the Quick Tune. Rather than sending a carrier for 5 seconds, the operator controls the duration. One key press sets the radio in FM mode and TX, then another key press returns your trusty Yaesu back to the original mode, in RX. This allows to have shorter and longer tuning times. Let's call it Manual Tune.

In between this new function and the original 5 seconds Quick Tune, lies Timed Tuning. 15 levels of delay are preset, so you can chose whether to tune for 1 second, 2s, 5s ... up to 15 seconds. It requires two key presses.

Finally, the Lazy PTT is for heavy ragchewers , those operators that speak for minutes before listening back for comments. Press a button, your radio goes into TX. Press again and the PTT is electronically released. No timeout, so watch out! This is a good substitute to VOX operation.

These functions should work on 817, 857 and 897.