Wednesday, 27 August 2014

Lithium-ion battery capacity test



I did a capacity test on my newly imported lithium-ion battery: Type DC-12680 the capacity is supposed to be 6800 mAH.

The image below shows clearly that the capacity is only about 2400 mAH i.e. 1/3 of the advertised capacity.

The battery has been on charge for 9 hours since then and is still not fully charged (Red LED still on). I therefor assume the batteries cannot be recharged at a high rate. 

Conclusion: 
It is unacceptable that the capacity is so much lower than the supposed capacity.
Rapid recharging is not possible with the provided charger.

IMHO they are still worthwhile considering. They are compact and weigh almost nothing. This is ideal for back packing with ultra-light QRP equipment.



Lithium-ion 6680 mAH battery capacity test.

Friday, 22 August 2014

Exceptional CW operator 4W/N1YC



I have been chasing James 4W/N1YC (9V1YC) for a while, conditions are not very favourable between Timor Leste and South Africa and he is constantly being bombarded by a enormous pile-up.

He has been pretty weak at best of times on all the bands, but even with all the odds against me (us) I have managed to work him twice. In both cases, he responded after the first or second call.

I am most impressed with operators of this calibre.

Long live CW

Wednesday, 20 August 2014

Unexpected surprises – Cambodia on JT65



I saw John AE5X blogging about working Cambodia and his concern about whether the person was legit.

As luck would have it yesterday I was playing with JT65 on 20m and I saw XU7AEU calling CQ. I was quite surprised to see such a rare entity using such a slow mode. However believing in the motto “work first worry later” I called in reply, the first 2 calls where in vain, I was swamped by the stronger European stations. I reverted to “Plan-B” I called slightly higher up in the band and that worked, the rest is history.

I looked up Alex XU7AEU on QRZ.com

I think I am extremely lucky to be in the right place at the right time.

Quote from QRZ.com:  XU7AEU

I will be in the Kingdom of Cambodia once again between the 19th and 28th of August 2014 operating from my usual QTH (our office roof in downtown Phnom Penh). After the lightning strike in July i'm still using the Yaesu FT-817 into a 20m dipole. I have brought more dipole wire so i'll be stringing up some other bands as soon as I can.

By shear chance I caught him on day 1 of his stay. It also shows the value of using JT65 with QRP and less than optimum antennas.

And if that is not enough, he used LoTW 



Saturday, 14 June 2014

Activating (almost) ZS/GP-001


I have just returned home after my first attempt at being a SOTA activator (goat)

Yesterday, I spent quite a long time carefully packing my kit in preparation for the trip. We awoke before sunrise and SWAMBO and I hit the road early, we arrived at our destination with some time to spare. In fact on the way I stopped to survey yet another summit: GP-002 on the way.

I immediately erected the telescopic fibre glass mask and hauled up the 20/40m linked inverted vee dipole. With that all done, we quickly took a few photographs for prosperity and then sat down and started connecting the Elecraft K2 to all the paraphernalia: Paddle, microphone, feed line and battery….. It was then I discovered a huge problem. The battery cable was not in the bag, I had inadvertently left it at home.

I had no choice, but to pack up and return home.

Even though no QSOs were made it still was a most pleasant experience. I recon I will do this again sometime.

Click on images for higher resolution.
Perdekop ZS/GP-001 view SE
ZS/GP-001 Perdekop



Tuesday, 10 June 2014

Ultralight portable station - batteries


A while back I blogged about methods of reducing the weight of my ultralight portable station:

I believe I have found the ultimate battery for my ultralight portable station. 

There is nothing new about the product below, but I have not had the opportunity to get first-hand experience with these newish devices.

Normally I would use a 7 AH SLAB - Sealed Lead Acid Battery (typical alarm type battery).

The abovementioned SLAB's had served me very well through the years, but there is only one small problem, they weigh 2350 g each. This weight is fairly substantial and would become an issue on long hikes.

I discovered on e-Bay that there are many Lithium-Ion batteries available with different mAH ratings and IMHO they are pretty reasonably priced.

The 6800 mAH LiON battery (same capacity as the SLAB) weighs is at 162 g. This is only 7% of the weight of the 7000 mAH SLAB and it is a fairly compact unit.

Assuming the “blurb” regarding the LiON batteries can be believed then I think this is the way to go. As some insurance I decided to get a 9800 mAH battery complete with charger.

I cannot wait to field test these units……

9800 mAH LiON battery pack

Saturday, 7 June 2014

SOTA statistics



Looking at the SOTA web site the following information can clearly be derived:

·         CW is still the most popular mode by a good margin. 46% of QSOs were made in CW, followed by SSB 32% and FM 22%.

·         The most popular bands are 40m followed by 2m thereafter the 30m band. This is understandable, but also a pity since it virtually excludes South Africans from participating on an international level.

Click on image below for a better view.

SOTA statistics