The JSCARC EOC tuner saga



I’ve been working on trying to repair the Building 30 Emergency Ops Center external tuner.  This is a big deal since our club is  chartered to support the center emergency radio capability.  Thanks goodness it wasn’t needed during Harvey.

The defective tuner is an MFJ 998RT full KW remote tuner unfortunately with a known speckled reputation of reliability.

Our EOC capability is currently inop due to this broken device, likely hit by lightning. 

After valiant clever attempts to fixed the “No Interface PIC” and “Wake up” circuitry and after a  replacement of a a PIC controller, the tuner is still not working.

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Belated W5RRR shack flood status


Our W5RRR shack survived another hurricane with flying colors.

Here’s a photo of the outside a few days after the historical flooding of 40″ that hit the Houston area.

Of sort, it’s a miracle that the JSC area, in general, sustained recoverable water damage across the center and the nearby areas.

However, immediately outside the surrounding 1mile perimeter one could see very uneven distribution of housing that sustained minimal to heavy flood damage.

For the W5RRR shack, water penetrated the front and back door seals and sprinkled a very moist layer of water across our aged carpet.  Unfortunately, this causes mold spores as well as a rich medium for the colonization of mosquitos by the back wall.  Not a new finding since it’s been a problem of the shack and flooding from past experience.  Photos show blowers in place to dry out the carpet.  Pictured are Keith KG5HOK and Chatwin KG5URC who arrived early to monitor the dry out.  Keith has secured an agreement in principle with the Gilruth to replace our treasured carpet with new tiled flooring.  Volunteers are sought to re-house the displaced mosquitos.  And in our backyard, our TH7DX which was being staged for installation onto of the 80′ tower was smartly anchored down on Tanner’s saw horses prior to the hurricane.  Early, we had considered laying the tribander directly on the ground (to mitigate Wizard of Oz wind gust events), but luckily we mounted these above ground.  All is good.

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Icom IC-781 status

The W5RRR IC-781 was taken out of commission during 2017 Field Day because we observed intermittant noise crackling on the receive and transmit signals.

It got on the bench for troubleshooting.  Based on online owner’s knowledge sharing, areas of known weakness were:

  1. cracked solder joints at the crystal filter in IF

  2. Phased Lock Loop unlock

  3. IF FET 2SK125s

We’ll I screwed something up.  After removing the RF module the whole receiver chain is white noise.

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Fixing a bad trap on the yagi

In preparation of the TH7 Yagi, Keith, Jerry, and John put finishing touches on the beam by re-measuring and lightning connections while the beam lay on the saw horses.

A final check with the MFJ259 VSWR bridge showed a poor resonance with at 20m.  Even we knew that the resonance with be displaced due to the close grounding effects, the 13 MHz resonance was way out of normal.  John quickly checked the traps for continuity and immediately found an open.  The team used Jerry’s tailgate to conduct a quick disassembly and inspection.  Oddly, the connections looked normal, but one end of the coiled wires had poor connection to the aluminum tube.  John flattened the wire, burnished surfaces, applied some Penetrox compound, and nursed it back into it’s protective shell.  Upon completion, the resonance was definitely better, but still low.  After the storm we’ll inspect the others.  

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Saturday Aug 20th Tower-Antenna crew (photos)

Here’s a series of photos of the team that came out on Saturday.
CLARC (Kelvin, Levi) teamed up with us (Keith, Larry, Jerry, Bob, Tanner and Dave) and together, we worked all morning thru mid afternoon.
The tower sections are pre-assembled and the TH7DX is pre-assembled as well.  All major work is ready for the Friday Aug 25 big tower/antenna construction event.

Read moreSaturday Aug 20th Tower-Antenna crew (photos)

Dumb n Dumber

That’s me.  On Saturday Aug 19th, the temperature was formally logged at 98F (Heat Index 103). The W5RRR tower team all worked under the sun for 6 hours. Several had also used Sunscreen and everyone had sun protection hats… except me.
This is kinda a public service announcement and reminder that the Texas rays of warmth takes no prisoners during the lazy unhazy days of summer. Sun protection should include sunscreen, sunglasses, hat and loose apparel that protects the body…

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W5RRR 80′ Tower takedown and makeover

W5RRR 80′ tower is undergoing a major makeover on August 25th.  Rusted sections of Rohn 45G tower sections will be replaced with newer pieces.  The guying system will undergo an update with new hardware and rescued brackets.  A newly rebuilt Ham IV rotor and a HyGain TH7DX tri-bander (10/15/20m) will be installed, replacing our tired and broken 20m and 15m monobanders.

The club is looking for any and all volunteers will to help out on either this weekend on August 19 for prep work (TH7DX and tower pre-assembly ) and on August 25 for the whole tower/antenna disassembly and reassembly.

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