Notes on Force 12 C-3E/H Triband Yagi

18 June 2013

Ordered directly from Force 12 factory by W0CG. /H version is for high winds, rated at 120 miles/hour. To be shipped directly to W8AV to arrive no later than 1 August 2013. Click here for invoice. Click here for manual.

8 July 2013

Shipped from factory to W8AV. Click here for shipment invoice.

7 September 2013

Discovered after assembly that the four 10 meter element center pieces were 2 feet each and all should be 4 feet each. Force 12 agreed and Fed Exe'd parts to us on Curacao, but as of 16 Sept they were still stuck in Customs.

17 September 2013

Installed in pieces on the tower by Jason, NR0X, mostly in the dark.

13 March 2014

Investigating 4:1 SWR on all three bands. Inspected BALUN and feedpoint connection and all looks good on tower. Connected coax jumper from bulkhead directly to Station 2 and still see bad SWR. Next to try is a different BALUN.

17 March 2014

Fabricated a new balun. Seven turns of an 8 foot piece, all new pigtail and new PL-259. Installed on antenna and excluded the factory balun from the circuit. Still same SWR problem.

19 March 2014

Opened the hardline - pigtail at top of tower. PL-259 going to the antenna was moist and looked corroded. I brought it down to re-do the connector. Installed a known good coax jumper at the top of the tower direct to the antenna but SWR problem persisted.  Next will open the hardline Type N at top of tower and inspect.

27 March 2014

Fixed. The antenna tested perfectly with the N4RV Rig Analyzer at the feedpoint. I opened the hardline connector and found considerable liquid water and evidence of rust inside the N to UHF adapter. Replaced that adapter and a UHF barrel with new from N4RV, reconnected the factory balun and reinstalled the coax pigtail and sealed all connectors. All is perfect now. The two wet connectors are in a baggie in the coax connectors box with an explanatory note.

8 December 2017

In April 2017 I noted white oxidation products and apparent corrosion at the 2 inch U-bolt saddles where the boom attaches to the mast plate. Ordered DXE 2 inch stainless saddles to Idaho. Today I (W0CG) removed one of the u-bolts and sanded off considerable pitting and white powder from all around the boom. It cleaned up well with very little surface pitting remaining and no structural concern. Installed factory new DXE saddle u-bolt on the upwind side. Will replace the downwind one on a subsequent climb. Nuts are 9/16. 1 hour on tower. On December 9 I put on the second DX Engineering saddle clamp. There was about the same amount of surface pitting under this as the upwind one. The old Force 12 clamps are in the grey misc antenna hardware box.