Monday, 7 December 2015

'29 BK QSO Party - Night #1

Harold - KB0ROB

This past Friday night's wonderful propagation during the ARRL 160m CW Contest, pretty much went into the dumper for Saturday night's 1929 Bruce Kelley QSO Party, sponsored by the Antique Wireless Association.

In spite of the auroral-like conditions, with the K-index reaching level '5', the melodic tones from many of the old (and new) clunkers could be heard pounding out their annual 'CQ AWA' invitations.

Among my 19 contacts (8 on 40m and 11 80m), the highlight of the night was working W2ICE/1 in Maine on both 40 and 80m. In reality, this was Paul, N1BUG, operating Bruce Kelley's original 10 watt TNT, which rose to almost S9 levels on 40m, once the sun had set. The Kelley transmitter is moved to various locations each year, a new AWA tradition.

As well, Larry (NE1S), also in Maine, was worked on 40m with  his 10W TNT.

A new station for my '29 logbook was George (N3GJ), in Pennsylvania. George was managing 8 watts input to his version of a 1929 TNT.

When I first tuned-in, several years ago, to hear what these 1929 signals sounded like, two of the best sounding signals were coming from KBØROB (Harold), shown at the top, and KBØMM (Burt), both in Minnesota. I could hardly believe they were using era-appropriate rigs as their signals sounded as good as many modern rigs. Thankfully nothing has changed, as these two stations continue to hand out 'MN' using their well-built 'MOPA'-style time machines.

Scott, WA9WFA, the BK score-keeper in charge of logs, faded up briefly with his fine-looking Colpitts.

Here is a list of the '29ers worked so far, along with their rig style and DC power inputs.


       KK7UV     Hartley    10w    MT
       W2ICE/1    TNT    10w     ME
       NE1S    TNT    10w    ME
       VE7BDQ    Colpitts    8w    BC
       K7SF    Hartley    10w    OR
       K4JYS    Hartley    10w    NC
       WB2AWQ    Hartley    10w    NV
       N3GJ    TNT    8w    PA


       KBØMM    MOPA    8w    MN
       KBØROB    MOPA    9w    MN
       W7LNG    TNT    7w     OR
       K4JYS    Hartley    10w    NC
       W2ICE/1    TNT    10w    ME
       WA9WFA    Colpitts    20w     MN
       KK7UV    Hartley    10w    MT
       W9TFC    Hartley    10w    WI
       N2BE    Hartley    10w     NJ
       KIØDB    MOPA    10w    MN
       WØLGU    MOPA    10w    MN

As you can see, 'Hartley' construction takes a slight edge. Vintage 'handbooks' and magazine articles from the era, have always promoted the TNT as the best 'beginners' rig but in reality, the Hartley is much easier to build and to get working with a good-sounding signal. The TNT requires some finicky tweaking of the grid coil in order to have an equally stable-sounding note.

I'm happy to report that in spite of the very high winds (as usual), my new MOPA's tone remained virtually unmoving ... for the most part! This was its first real workout and after my first QSO on 80m, my frequency began making large jumps and suddenly sounding very unstable, along with fluctuations in power output. My initial thought was that one of the old original mica caps was starting to breakdown.

After disconnecting one lead of each capacitor (one at a time) and temporarily clipping in a modern substitute, I was no further ahead. I had originally isolated the frequency instability to the amplifier stage and there was only one thing left ... the amplifier's grid-leak resistor. It appeared to be slowly failing, by increasing resistance in jumps. The 12K resistor was now measuring ten times that value and quickly rising. A new 12K, temporarily clipped in place, cured the problem but it had cost me over an hour of operating time ... probably the best prop of the night as by the time I got back on the band, signals were weak and auroral-sounding.

Hopefully the bands will have mended themselves by next Saturday night, allowing some of the smaller eastern stations to make it back to the west coast for some memorable '29 'transcons'.

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