CQ 160-Meter Contest, CW
Call: AC0C
Operator(s): AC0C
Station: AC0C
Class: Single Op HP
QTH: KS
Operating Time (hrs): 6
Summary:
Total: QSOs = 412 State/Prov = 55 Countries = 8 Total Score = 60,102
Club: Kansas City DX Club
Comments:
I love this contest. Fast rate and tons of good signals. Friday night was
really quite and Saturday was pretty good as well.
Worked signals from 1800 all the way up to about 1900 but kept the run
frequencies generally in the 15-40 range. About 6 hours of op time. I did not
get out of the attic following some work on the 20m yagi until the evening
Friday so got a late start. And between the wife's honey-do list and the
kids activities, I did not get to the key till about 9:00 PM each night.
Final results were 47/48 states including a couple from DE and DC â€" quite a
surprise to hit DC twice! Had to double check QRZ.COM as I thought I surely
copied his call wrongly. No AK or HI though. DX was tough to come by, but
around 1:00 AM or so I picked up a couple of UK Qs.
Caribbean and a lot of CN were missing as well. I should have went out and
turned the loop a bit because the null is probably impacting the north/south
signals from the W7 were especially weak which makes sense given the loop was
pointed about NE/SW. Of course, for the Caribbean, having the stucco covered
house with its chicken wire mesh under-layment in the way must be contributory
to the hard-of-hearing condition!
Equipment used: Yaesu FT-2000 with NS roofing filter mod, Alpha 76pa.
Antennas are trap loaded 80/160m stealth attic-mounted dipole for transmitting.
And an outdoors diamond receiving loop about 8x8 feet in size.
The NS filter again worked very FB - locally KU1CW was S9+50 and yet I was
able to work some stations located just a few hundred hz away from him in S&P
mode in a couple of cases - something impossible to do with the stock
filters.
The transmitting antenna is resonant about 1850 and has about a 25 Khz 2:1 and
50 Khz 3:1 bandwidth. A remotely activated hairpin is engaged on 160m to
offset the low resistive feed-point caused by the loop and cap hat loading
structures â€" and the results are excellent â€" 1.05:1 at resonance with the
hairpin in place. I did not use the tuner in the contest - something that I
try to avoid since the debacle of 2010's RTTY RU, but I could fine tune
the antenna by clipping on a couple of feet of wire on the end - which was
almost as convenient â€" as one end of the antenna is accessible without much
trouble.
Only difficulty was that the transmitting antenna is pretty narrow banded and I
have to keep a watch on the amp tune as I QSY. The new amp instrumentation
board worked great â€" especially keeping me out of trouble when grid currents
would sneak up (caused by higher SWR as I QSY further from the tuned
frequency). Toward the end of the contest, I figured out that if I would just
cut back on the drive a bit, the power out would go down but I would be
spending less time touching up the amp
Earlier in the week, I had converted the loop from an unshielded variety to the
shielded type. I can't say that I noticed much of a difference based on my
memory of running the unshielded style in the December SP. In either
configuration, the loop is a rock-star compared to the dipole. Domestic
signals were much better copy on the loop although the DX that I heard was
generally a bit better on the dipole. While their NA performance is very good,
due to the high TOA, both of these antennas have terrible DX performance and it
shows in the minimum number of DX QSO worked.
I am thinking of putting a loop base mounted preamp up â€" not because the
receiver is not sensitive enough. But rather, to get signals high enough to
engage the AGC on the rig. Riding the AF gain and the RIT is one too many
knobs to attend too - especially as the dits and dahs start to blur together.
And I need to take a look at the back EMF clamping on the relays in the loop
- there's a bit of an audible click in my RX and the external AF filter
when transiting from TX to RX - which I suspect is due to a little bit of spike
being induced into the RX line from the relay switching. Rounding off those
edges will fix that right up.
73/jeff/ac0c
