Notes on CL-33 Tribander
November 2000
Antenna was on PJ9JT tower at the time of purchase. Cleaned up by K4LT and placed in service.
July 2001
Removed from aluminum tower and rehabilitated by N8NR and N8BJQ -- lubricated, waterproofed, tested. Installed at top of 80 foot US/JA tower.
September 2005
Routine checks showed high SWR on 15 meters and intermittently high SWR on 20 and 10. It was about 3.5:1 on 15 in the SSB band.
CQWW SSB 2005
Worked OK during the contest, but it did not seem that the antenna had much pattern and it was generating considerable interstation interference.
3 November 2005
Took the connector off at the feed point to run the MFJ meter. The Type N male and female pins were black inside the female Type N on the antenna and they disintegrated when the connectors were pulled apart. This explained the RFI in the CQWW SSB contest. Took the driven element down with help from Cindy. On 4 November removed the connector on the antenna body and replaced it with a female SO-239. This was tricky, as the connector connects to two roughly 10 foot long heavily insulated black wires that sit inside the DE, connected to nothing. Taped the cut far ends of these wires, fashioned a connecting method for the new connector, put it on the DE insulator body, and waterproofed it.
Put the DE about 8 feet up on the Europe tower and ran MFJ curves. Resonances were shallow and not in the bands. Replaced both DE traps with the new ones from WB9Z, then flipped each to try all possible directions of "in" and "out" until getting a workable combination. SWR on 20 and 15 is not perfect, with dip in the phone band. On 10, the dip is at about 27.6 MHz., but is acceptable from the end of a long piece of feedline. Connected RG-8X from the shack and ran 100 watts to the antenna all seems OK except for slightly high SWR on 10.
Measured physical dimensions and compared with the antenna manual. Spacing does not agree with the manual: from center to inner tip of trap is 106 inches against manual number of 101.5 inches. I took out 5 inches in both sides as an experiment and dips were way too high in the band. Put back to original positions, as we know these work. I'm not certain that the manual we're looking at ("CL-33-M") is the right model.
22 November 2011
W0CG removed driven element. With DE on Europe tower, 15 and 20 are perfect, but the 10 meter dip is at 27.3 MHz. Replaced traps with WB9Z rebuilds. Note from W0NB: Mosley Classic-33, salt, humid air, corrosion, short, then heat from non-resonant circuit melts & burns thru coil form and aluminum tubing. Similar damage these components which are presumed to be original John Thompson components. These replaced 4 years ago. Replacement traps have failed in a similar fashion with salt corrosion appearing to be major factor precipitating the chain of events. 22 November, 2011. New driven element traps installed and array exhibits low SWR all bands. W0NB will take the bad DE traps to the States and get them rebuilt. To make this repair work, all the spare traps were disassembled and two good ones painstakingly fabricated.
Now we need to get more parts. See E-mail to WB9Z sent 23 Nov 2011.
But now we are out of spare traps parts. We have some eight various traps and parts of traps, but every single one of them has a burned out, useless coil form, so we need to get at least two more good traps for the driven element. To add to the confusion, it seems that our old, old CL-33 may have slightly different element dimensions from the newer ones, so it may not be safe to simply order a new set of driven element traps, as they may not work right in the old, 1968 antenna.
Jim (W0NB) has offered to take the lead on getting us some new or good rebuilt CL-33 driven element traps, but maybe you can put him in touch with your guy to be darned sure that we are getting the right stuff? Our objective is to get two good spare DE traps to put in when the present ones fail out.
6 Dec 2012
Installed 10 meter only driven element fabricated by WX0B. Antenna works great on 10.