Three summits near Ballarat

Hi all,

To ensure that the brownie point balance was kept in check, I did not plan a multi-day SOTA adventure this Easter. I did, however, get leave to activate three summits near Ballarat, all which I had activated before.

After my troubles with antennas on the March long weekend, I decided that I would repair the random wire with high grade wire near the BNC adapter. The antenna had failed by the wire simply tearing at the adapter. My solution was to solder about 1cm of the wire on, and use tape to try and give greater physical support to the wire, so that the load is not borne at one particular spot. I also reinforced the counterpoise wires in a similar fashion. The photo below (if you click on it), shows the changes to the random wire (you may need to zoom in on the KX1).

Mt Buninyong VK3/VC-018

I had not activated this summit since 2012. My previous activation used my original setup of the 8 segment aluminium pole vertical. I had not used verticals for a while now, but when I do, I rely on a squid pole to give physical support to a wire going up – a squid pole is more convenient. For this activation, it was the random wire. Here is a look at the setup I used here:

Station at Mt Buninyong

Station at Mt Buninyong

I headed up the road and parked in the activation zone. There is a walking track heading down the hill from the carpark near the lookout tower. I used this to leave the activation zone and reenter it for my final nonmotorised access to the summit.

For these activations, I used the shorter 4.7m squid pole. For local contacts, it makes little difference between using the shorter squid pole or the longer 7m one. I was keen to give the shorter pole a bit of a workout, as I have a trip upcoming to the states. The shorter pole fits in the luggage I plan to take. The larger pole does not, so the shorter pole looks like it will go. I also had an eye on what I might do at the end of the year on the Lord Howe Island trip.

Another eye on the US trip/Lord Howe Island was not to use an external power supply on these three activations. I used only the NiZn internal AA cells, with no LiPOs in the car or anywhere else to go grab if something went cold. My station is simply the KX1 box, the wire and the squid pole. The whole lot is under 1kg. This is my planned US station.

The KX1 has little difficulty tuning the antenna on 20/30/40. The pattern remains that the most amount of power is developed on 20, then 30 then 40, with 40 being generally around 1 watts on a 10.5V supply. The typical report I receive is 559. 40 remains a reliable band for close in contacts. If I can self spot, then getting 4 CW contacts quickly on 40 is just about guaranteed these days.

Getting the good reports on the NiZn batteries shows that this minimal setup works.

As for my broken end-fed, it would appear that the problem there is that the toroid inside has physically broken due to the rumble tumble of many activations (eg hitting the ground when being quickly uncoiled). The matchbox is closed, but looking at people on the internet who sawed it open, the only thing that could make the rattling noise that I experienced is broken pieces of the toroid. I am still working out how to repair it. Considerations are:

  • For CW activations on the KX1, I think the random wire does as well or better than a EFHW in an inverted V formation with a 7m squid pole in the middle. The EFHW might perform better on a bigger squid pole, but here I am using a 4.7m squid pole with the random wire. The key advantage of the random wire is that there is no feedline – the antenna itself connects directly onto the BNC connector of the KX1. There will be no feedline losses.
  • For the FT-817, I lose the inbuilt KX1 tuner and that is losing a whole lot of convenience. My options are either the EFHW (at least on a 7m pole), or use a vertical if I am after DX. I think dipole based antennas (doublets, etc) are going to be cloud warmers, just like the EFHW, unless I can genuinely get them up higher – eg putting a doublet on two 10m squid poles, one at each end. Ian, VK5CZ introduced me to the SOTAbeams EFHW tuner for 5 watts. I think I would base a new end fed on this matchbox. It gives the option of a counterpoise, which my old end fed did not have. Matchboxes like this are really a convenience thing, as the matchbox itself can be homebrewed without much difficulty.

So, I think I’ll leave the old end-fed for now, and hopefully get around to building a new one based on the SOTAbeams end fed matchbox.

Mt Warrenheip VK3/VC-019

Mt Warrenheip was more of the same. A sealed road goes to the summit area. I parked in the activation zone, but at the eastern end of the road (final turn before the summit) and then walked down the ridge to exit the activation zone, turned around and reentered it.

This activation was again on the short 4.7m squid pole and the random wire. One thing about this setup is that it is quick to put up and tear down.

VK3/VC-032

My final activation for the weekend was at this unnamed summit. Bush Search and Rescue Victoria are having a training day the following month just down the hill from here. My part is to operate a GPS based rogaine training exercise, so I met up with the organisers to do a reccy of the proposed course. After finishing up with them, I headed up the summit, and basically did the same thing as at Mt Warrenheip.

All three of these summits are nice easy summits to get started for those nervous about taking the SOTA activation plunge. Even CW activations on 40m are straightforward these days if you can self spot. If you can’t, its getting a lot easier as well.

I tested the voltage of the NiZn AA cells after the three activations. They started at 1.8V per cell, and were about 1.77V at the end of the day. They can clearly handle these activations and have plenty of left over capacity. Given that NiZn batteries prefer shallow cycles rather than deeper cycles, I would be using them as recommended. Running on these NiZn AA cells gives me most of the developed power I get when I operate using external LiPOs. It would be far ahead of using 1.5V non rechargables – the 1.5V is only when they are full – when they are about 50%, it’s 1.3V (that would be 7.8V total). Stories on the internet about the KX1 suggest that at around 7.5V, the KX1 is typically only generating 300 to 500mW. If I used NiMH, they quickly settle to 1.2V for 7.2V total for 6 cells. This is close to the KX1 low voltage cutoff – Elecraft don’t recommend running the KX1 on 6 NiMH cells, but if I did – it would be true QRPp activating. QRP does interest me, but I perhaps are not so much into the QRPp thing. As it currently stands, the NiZn cells are an excellent internal power solution for the KX1.

So, not too bad getting 3 summits in, although none of them are new uniques for me. Still, it had been a month since my last activation, so you have to take them when they come.

Regards, Wayne VK3WAM

Internal FT-817 NiMH battery option

Hi all,

A while ago I wrote about options for internal batteries in the FT-817. As detailed in that post, some are trying out LiPO options in the FT-817, and HobbyKing sell a 2600mAh 3S option. Provided operators watch the voltage level on the FT-817 screen to avoid excessive discharge, that would work well.

I still prefer keeping the LiPOs out of the radio – I am more than happy to use them as an external power source and often do. However, the internal battery is not great weight bank for gram. It has a 1400mAh labelled capacity. Mine would still be delivering the vast bulk of that even though I have extensively used it. It gives about 1 hour 20 minutes to 1 hour 30 minutes action when doing a SOTA activation with TXing at 5 watts. I have a BHI noise filter which is a little expensive on the juice, the 817 is drawing about 420mA on RX.

In my previous post, I highlighted that many NiMH batteries do not make the grade in the FT-817. They might get close to their labelled capacity (2100 to 2500mAh) typical on lower currents, but they struggle when 2A is called for. I did notice that the HobbyKing 2400mAh AA cells could handle a 2A load, so I was interested in trying them. That time had now arrived.

I used the 8 AA battery holder that comes with the FT-817 and loaded it up. This holder needs to be put in the radio either empty or with 4 or less cells as otherwise it jams. Care also needs to be taken that the cable does not get jammed as well. The holder can be subject to open circuit faults and I had a little bit of trouble with this.

HobbyKing AA cells in a FT--817

HobbyKing AA cells in a FT–817


After sorting out those issues, I got on VK3REC, a local repeater, and proceeded to rag-chew at 5W FM. This would present the highest current load on the batteries. I was able to operate for nearly 3 hours before the batteries got to the end. Nice result, and the HobbyKing cells had no trouble throughout the discharge cycle.

Near the start, the 8 cells would present about 10.1V on RX and 9.1V on 5W FM TX on a multimeter. The FT-817 display would show 9.6V and 8.4V at this time. The 8.4V on TX remained at that level for about 90% of the discharge cycle. The final part of the discharge cycle was more graceful than the internal battery, with the RX voltage slowly drifting down from 9.2V FT-817 display to 8.8V. The multimeter was about 0.2V above each of these levels. The 5W TX was at 7.8V when I stopped the cycle. The FT-817 will power off if it drops below 7.5V.

On the whole, I am very happy with the AA cell’s performance and can recommend it for use with the FT-817. I would suggest charging the cells individually in a NiMH smart charger. Alternatively, two lots of 6 hour charges in the FT-817 should fully charge the 8 cells from flat. The green cable in the battery pack needs to be disconnected for the FT-817 to charge the pack.

73, Regards, Wayne VK3WAM

FT-817 Internal battery ideas

These days, FT-817ND units are supplied with the Yaesu FNB-85 battery pack. This pack consists of eight NiMH AA cells in a shrink wrapped package. The rated capacity of the pack is 1400mAh. NiMH cells have a nominal voltage of 1.2V, so 8 times this is 9.6V.

The capacity of this pack gives me about an 1 1/2 to 1 3/4 hours during a SOTA activation. SOTA activations at the moment can involve a lot of CQing, so my rough estimation is that I would be looking at a TX duty time of at least 30%. I also have a BHI filter installed, so my 817 is heavier on current draw on receive – about 417mA with the volume down, and 430mA typical on receive. Obviously more on TX. This leads me to believe that at the moment, I am getting capacity “in the ball pack” of the rated capacity.

Quite a number of my trips involve multiple activations on a single day or trip, and the internal battery is not enough to keep going the whole time. At the moment, I supplement the operating time I get from the internal battery by using either LiPo packs or three LiIon 18650 cells in series in some PVC pipe, and then plugged in via the external DC jack. This is meeting my needs for the moment.

There is no doubt that by using 3 cell Lithum technologies, there is plenty of options for external power. What about internal – when the FNB-85 dies sometime in the future, I will want to replace it, but I want something better. Given that it is working well at the moment, it would be a little indulgent of me to replace it now, so I won’t – but it is nice to have a plan. It is also nice to have more capacity than 1400mAh. Something north of 2000mAh, perhaps even 2500mAh should be achievable.

A LiPo pack in the internal battery slot

Glenn, VK3YY experimented with putting a Turnigy LiPo inside the FT-817. See his picture below:

Turnigy LiPo 2500mAh battery

This battery can be found at HobbyKing at:

http://www.hobbyking.com/hobbyking/store/__23814__Turnigy_nano_tech_2500mAh_3S1P_5_10C_Transmitter_Lipo_Pack_.html

It has a lower C rating than many LiPos as it is optimised for RC transmitters, rather than the boat, plane, helicopter at the other end that could be drawing 100A plus. The FT817 is going to only hit it with 2A, which is only 0.8C – a walk in the park given its 5C discharge rating. The voltage of the pack would be 12.6V fully charged and 11V or so when discharged – so the voltages will be perfectly fine for the 817. Some care is needed as the battery will provide some additional operating time down to 9V, but this is not recommended. The operator needs to pay attention to the voltage display on the 817 screen. The 817 cutoff is 7.5V which would drive the LiPo pack too low – this is 2.5V per cell if it was perfectly balanced. If even a little unbalanced, one cell would be even lower, which is not good.

The LiPo is is a good solution, but it is a higher maintenance solution given the cut-off issue above. The FT-817 is also not designed to charge LiPo packs, so the LiPo needs to be taken out to be charged. It really needs a proper LiPo balance charger to keep the cells in line with each other. Care would need needed if this battery was installed fully charged and an external DC power supply be attached, as unless the green battery cable is connected to a meaningful voltage, the FT-817 will trickle charge 10mA into the battery. This is bad for a fully charged LiPo pack!

NiMH solution

The 817 is supplied these days with the FBA-28 battery holder. This is designed for use with Alkaline cells. These cells are not going to handle a 2A current draw very well, so I can’t imagine that there are many in the world who are using this holder in this way. The holder is pictured below:

FBA-28 battery holder

I have put in a number of Energizer 2450mAh NiMH battery cells into the holder. Eight are needed to complete the pack. The pack is a little difficult to get into the 817, but the trick is to put the holder in first empty, and then put the batteries in.

Yaesu do not recommend using rechargables in this pack. The main reason for this is suspected to be the risk of a short. The Cathode of a rechargable AA NiMH is the outer shell. Aside from the last cell in the pack, this will have a voltage difference to the case, and some of the cells can rest against the case. The only protection against disaster is the outer label on the cells, and this can be scuffed away. The picture shows that there is a plastic tab that will cover about 2/3rds of the lower 4 cells, but some electrical tape put over the exposed cells will also aid in providing the necessary protection. I would not think it needs to be comprehensive coverage, but two strips over the top 4 cells, top and bottom, and one strip over the 4 bottom cells at the exposed tops should be enough. (Of course half the cells are facing the other way so their top will be the other cell’s bottom, etc).

One final modification is the green cable. This is connected between cell 4 and 5 in the pack. If this cable remains connected, the FT-817 will not charge the pack. This cable needs to be cut and secured, and then everything will be ready to go.

Appropriate NiMH cells

My picture above shows Energizer NiMH cells. These are rebranded Sanyos. They work well in many applications, but unfortunately, not this one. Even though fully charged, the voltage drop when the 817 hits them with near 2A is too much, and so the effective life of the pack is much lower than the 1400mAh Yeasu pack. The labeled 2450mAh capacity sounds real nice, but the real world experience would suggest much different. I have tried them in non-radio applications with current draws of around 500mA, and they work ok there.

I found that HobbyKing sell NiMH cells, including some low discharge 2400mAh cells. This is a great capacity for a low discharge cell. I have also read that some have tested these cells at 3A and they work well. I am getting some of these cells to give them a test, but if they can handle 3A, they would be a great cell to use in the Yeasu battery holder. The 2400mAh capacity nearly matches the 2500mAh LiPo pack. Both solutions should give nearly 3 hours of heavy SOTA activation time, but the NiMH solution can use the internal Yaesu charger (2x 6 hour charges back to back), and there are no concerns about damaging the pack if taken to 8V or so.

Regards,
Wayne VK3WAM