P40L-P49Y Contest Summary Information

We twisted Ed’s (W0YK’s) arm a bit to get him to stay on again for an extra week following the CQ WPX RTTY contest to round out a multi-single team for ARRL DX CW with me, W6LD/P40L, and Chad, WE9V.

We were intent on having an effective in-band S&P station this time. Last time we’d tried in-band S&P (in CQ WW CW), we’d set up a vertical about 800’ from our main transmit antennas to act as RX antenna on 10 through 20 using an EA4TX and 2x2 switch to swap antennas. Even though we were LP, we picked up too much noise on the RX vertical from our transmissions making in-band S&P very ineffective (other than on the low bands where it was somewhat effective because we could use the beverages as the RX antenna). This time we set up an old Cushcraft A3S on a portable 30' tower situated in the “Cunucu” about 500' SE from the main transmit antennas. The result was that the monobanders and the A3S had their element tips pointed at each other when beaming NAm (i.e., maximum rejection) and the interaction was minimal. Since the A3S is reasonably effective on both TX and RX, we decided to dispense with sharing of the main yagis as TX antennas between the Run and In-Band S&P station 10 through 20 with transmit timing controlled by the DXLog software lock-out. The result was the in-band station could easily pick off stations within 10kHz (and with some effort within 5kHz) of our Run station. For the low bands, though, we used the EA4TX interlock with a 2x2 switch to share the main transmit antennas between the Run and In-Band S&P station, and both stations listened on the usual beverages remotely situated in the "Cunucu".

We felt the in-band S&P was reasonably successful this time and that our use of it improved over the course of the weekend as the team got better working with timing of transmissions and corresponding interlocks (hardware and software) to interleave Qs. By the end of the contest, the in-band station had contributed over 500 Qs to our total. A significant portion of those (but not all) are likely additive to our overall Q total.

The station was set up with 3 rigs and 4 computers: (1) a K4D that could be keyed by either of two computers/operator positions (allowing two operators to operate the run station at the same time with a the first op to transmit “winning” the ability to transmit (controlled the DXLog software interlock); (2) a K3/P3 for the in-band run station (with transmission time access controlled by both the DXLog software interlock and the EA4TX interlock); and (3) another K3/P3 as back up (and which, at least in theory, could have been used to work a few additional Qs on the non-run band subject to the hour band change limitations. The two Run positions and the In-Band S&P position were set up for audio sharing (which seemed to be rarely used in practice). The only serious issue encountered with the set-up was that the logging software would freeze sometimes, apparently as a result of the software interlock being unable to cope with two run operators occasionally attempting to transmit almost simultaneously on the run radio. We need to experiment to see whether that problem can be addressed by adjustments to the timing settings or whether the DXLog software interlock simply cannot cope with this set-up.

A couple of days before the contest, Chad was seeing some weird SWR readings on the 6L 10 meter yagi while playing around on the digital modes. There was clearly some intermittencies that presented when the antenna was rotated. It was bad enough to warrant getting Ed to “suit up” and physically inspect the connections at the top of the tower. Ed was able to determine that the flexing and unflexing of one of the jumpers with a junction in or near the rotator loops had resulted in the shield tearing where it had been soldered to the PL259 connector (using the “K3LR method”). He was able to implement a temporary fix bridging the shield and the PL259 shell with a copper wire held in place with hose clamps. Fortunately, that lasted until we could make a more permanent repair a month later while we had a manlift on site for tower painting.

We enjoyed following others' progress throughout the weekend on the Online Scoreboard, including trying to catch-up and then stay ahead of the great work by the V3T team in our category and trying to catch-up (got close at times, but never quite got there) with the PJ4A team on nearby Bonaire in the M-S HP category.

The P40L team,

W6LD, WE9V and W0YK

	Station (all towers, except 30’ portable tower, on a 100x100’ lot):

Rohn 45 tower (66’): Single boom 2-element shortened 40m interlaced with 4-element
20m (68’) (JK2040, long-boom version); 80m Inverted-V (65’); 160m Double-L center-fed 
vertical dipole (65’)

North Rohn 25 tower (56’): Single boom 5-element 15 interlaced with 6-element 10 (58’)
(JK1015 configured for dual feed)

South Rohn 25 tower (45.5’): Tri-bander (JK Mid-tri)

Temporary in-Band 10 through 20 antenna:  Cushcraft A3S situated in the Cunucu about 
500’ SE from main transmit antennas on 30’ portable aluminum tower, fixed beaming NW

Receiving antennas: 4 Beverages controlled by K9AY 2x8 switchbox: JA/West-US (800’),
East US (500’), EU (800’)and East-West (AF and OC) (350’)

Rigs:  K4D (main run position); K3/P3 (for In-Band S&P); and K3/P3 (for back-up and
potential other band S&P)

Logging:  4 computers running DXLog.net

Interlocks and related switching:  DXLog software interlock;
EA4TX hardware interlock with 2x2 switch for sharing of transmit antenna on 40-160.

	
	

Thanks and 73 on behalf of the P40L team,

John, W6LD