Repairing RJ45 plugs on Icom mike leads

I have had problems with my Icom HM103 mike leads, caused by breaking the locking tab off the RJ45 plug.  This happens usually because the mike and lead are slightly tangled with other gear in my SOTA backpack, even though I use a plastic box to carry the small pieces like headphones, morse paddle, microphone and adaptors.

It also happened once before when I had the microphone of the IC706 stored in the central console of the car.  Pulling it out of where it was carried without due care for the plug  eventually damages it.

And without that little bit of plastic, the mike does not stay in the plug for very long.

Having broken the plugs on my IC703 mike and on the IC706 mike recently I decided to replace the plugs but add the shrouds or covers that protect the crucial locking tab.

The unprotected plug looks like this:

The plug with the protective shroud looks like this:

As a small issue found when re-terminating these plugs, I found that the shield connection was originally made using very small diameter heat-shrink or some other method of making the shield connection look like one of the other wires.  These plugs connect to the wires using connections that cut through the insulation.

I looked for heatshrink tubing that could be used for this purpose, but the smallest I had was labelled 1.5/0.8mm.  A shopping trip to my local computer/electronics parts agent in Yass produced no thinner option.  When compared with the existing wire, the diameter when shrunk was too large to fit into the slot of the connector.  So another method had to be found.

For the first mike I had cut the lead right at the point where the wire enters the plug body.  This created a problem with the shield connection and I had to try to form the shield into a narrow form so that it could slide into the appropriate slot.  After twisting it to create a spiral of multiple strands, it worked but I wished I had found a way to preserve the original insulation.   So when installing the second plug I didn’t cut the wire at the back of the connector, instead I cut the entire connector just behind the crimp point for the conductors.  That way I preserved as much as possible of the original shield wire assembly inside its insulation.

Cutting through the plastic plug body was simple enough but I did that in about 6 sections, ensuring that the wires were not damaged.

Result: a robust plug assembly on both my Icom microphone cables.

I am hoping this surgery will provide longer life for the plugs.

Footnote: I know blue shrouds don’t look right on these black cables and black radios.  But that does not worry me one bit.  And the mike is safe for children.

QRP challenge for 2017

My SOTA friend and collaborator Andrew Moseley VK1AD has proposed a QRP challenge for 2017.  He is going to aim to use 2.5w when activating summits during 2017.  

I have started to do the same and my activation at Mt Ginini on 27th December was made at 2.5w for SSB and 0.5w on CW.  I made about 20 contacts and although some chasers found lower signals a problem, I not only qualified the summit on several bands, I also qualified with CW at 0.5w.  One contact was with Steve VK7CW who also used an FT817 at 0.5w, the lowest power setting of the radio. 

The radio used was an FT817, powered by an internal LIPO 3S battery (windcamp).  I had a spare battery but it was not needed.  The 817 will not be as efficient in terms of output power/DC power consumed, as the bias current on the final amplifier stage will remain the same as it would be at 5w.  

A fringe benefit from using lower transmitted power is that battery life will be improved.  I had previously used the 817 with the internal battery at Mt Mundoonen on 26th December for a short activation.  I did not recharge the battery after that activation as it was only used for 5 contacts plus some listening.  After the Mt Ginini operation, the battery voltage according to the meter on the 817 was above 11v.  It can go down to 10v without any problem for the 817. 

Although we were on the downward slope of sunspot activity, making HF communications less certain, there are still sunspots and occasional sporadic E openings on HF bands.   

It will be interesting to see how the QRP challenge goes during 2017.  Progress reports will be made by both Andrew VK1AD and me.  

Mt Tantangera VK2/SM-024 activated on 10th December 2016

I was invited to join in an activation of Mt Tantangera by Andrew Moseley VK1AD, and was very pleased to be able to join him in this expedition.

Andrew collected me from my weekday accommodation in south Canberra at 7:30am on a brilliant summer’s day that Saturday morning.   We decided to take both our packs to give us the option of working on several bands simultaneously.

The route taken was through Tharwa, south of Canberra, along Boboyan road until it meets the Snowy Mountains Highway between Cooma and Adaminaby, but only a few km short of Adminaby.  The trip through the mountains took us past familiar scenery, Mount Tennant just after Tharwa, the Clear Range to our east, the turnoffs for the old Orroral Valley and Honeysuckle Creek tracking stations, including various SOTA summits like Booroomba Rocks, then past Boboyan Range and Pheasant Hill.

After 2 hours we arrived at the Rocky Plains camping ground.  We prepared for the walk to Mt Tantangera, adding sunscreen, hats, packs with water and food, antenna poles and navigation details.

Track up from Rocky Plains camp ground
Bush view to the side of the track
Track easy to follow
View to the south west while en route to Tantangera
bushland
Andrew VK1AD stops to take a photo too, sometimes!
A track marker showing 1km to the summit – a welcome sign

Many of the horse riders camp at Rocky plains and some even set up temporary areas for their horses to roam in, with temporary electric fencing.  The initial climb up to the saddle is steady and follows a bridle trail.  Some hoof marks are apparent in the soil as you climb upwards.  The condition of the soil was damp but firm.

On arrival at the summit, a very wide flat area, we found the trig point was ideal for attaching a pole to.  Initially we set up our equipment and antennas expecting we would be able to operate the two stations on different bands.  However I received wideband noise whenever Andrew’s FT857 was transmitting.  I decided to move my equipment about 30m away, assuming it was a proximity problem and a bit of spacing would help.

That did work ok, so it was then time to get onto the bands and hand out some reports.  The bands did not appear to be in good condition.  I made relatively few contacts considering the exotic nature of the summit and its SOTA value of 10 points for anyone making a contact.   I decided to use CW mainly so as to give the CW operators a contact, and I knew we would swap bands later so Andrew would be operating on 40m ssb.

I made one contact on 20m CW, then 6 on 40m CW.  One S2S contact was also made with Ian VK1DI at Booroomba Rocks on 2m.  One of the photos taken was of a March Fly (aka Horse Fly) of which there were many.

March Fly
Station setup (photo: Andrew VK1AD)
Lake Eucumbene in the distance

Thanks to Andrew for offering to share this activation.  While band conditions were less than ideal, we had a great day out in the snowy mountains region and enjoyed our walking and radio operation.