Well, it's taken me awhile to post this (now in the last week before my wedding), but here it is.
Last Friday morning I headed up Red Hill again and had a great morning with my FT-817ND feeding my WA5VJB Cheap Yagi. Good contacts into both NSW and VIC were made on a maximum of 4W (more on that below). Here's the log:
Call – Recv QS – Sent QS – Notes
VK1CJ (John) – 55 – 57 – Canberra
VK1BG (Ian) – 58 – 59 – Canberra
VK3BJM (Barry) – 51 – 41 – Victoria
VK1DA/m (Andrew) – 51 > 59 – 51 – Barton Hwy, NSW/ACT (signal improved in ACT)
VK1DR (James) – 59 – 59 – Mawson, ACT (Just down Red Hill from me)
VK3II (Jim) – 51 – 51 – Victoria (near Western Point Bay, but I couldn't find this on Google Maps), significant QSB
VK2BX (Brian) – 51 – 51 – Between Kiama and Nowra
So, not a bad turn result for an hours play time. Great to see James (VK1DR) up and active by simply mounting his beam on a tripod in the garage – good effort and adhering to the principle of, "the best setup is the one you actually have and use"!
Starting to notice a pattern with the QSB (which all the regulars no doubt are well aware of – but new to me) with peak times being around 8:30am and 9am. Look forward to further observing this in the future.
Also observed the benefit of being able to peak a beam in my attempt to pick up Brian (VK2BX). At first he was very faint (off the back of my beam) but I could hear him making a contact down to Jim (VK3II). So I played around with my beam and peaked him and then attempted a contact. Great stuff!
On to my output power. First up, I'm currently experimenting with a fairly lightweight setup by using the smallest practical Sealed Lead Acid (SLA) battery – practical regarding run time. This means, I've gone with a 1.2Ah battery – however I do also have a 4Ah one on standby. The reason I do this is in the interest of a truly portable setup. My ultimately goal is build a nice wooden case for the FT-817 with associated cables, speaker and battery. And ideally, it'd be great to take this with me when I go to Tassie and the like on the plane. Further though, the easier it is to pack up the car for the morning sessions the better – and no one enjoys lugging around big gel batteries so I'll save that for field days (where I need to operate for many hours).
Anyway, as a result of using the little guy, it means at full charge I put out 4W peak – according to my bench test at home with RF meter, dummy load, and using FM as the mode. (Now, I'll quickly acknowledge this is not a correct determinant of PEP, however it's good enough for my purposes.) In the FT-817 specs it does explicitly say that the full power of 5W is only when powered with 13.8V DC, so that's no surprise (and not going to be obtained with 12V batteries – not even the gel cell).
However, the key thing here is the 4W is only at full charge. With only 1.2Ah it means by about half way into my session I'm down to about 3.75W and that's when the low power (output) indicator starts flashing on the FT-817 – signalling less than 5W output (if it's solid, it then signals 2.5W output). At first I thought this meant I was indeed down at 2.5W, so when I got back home on Friday afternoon I hooked up the same battery to see what it was putting out.
To my pleasant surprise I was still putting out a whopping 3.5W (on FM) – which was great considering I expected 2.5W. Further, this means I made the contact to Jim (VK3II) on 3.5W as the indicator had started flashing by then. And as Ian (VK1BG) said, that's pretty good watts per kilometer. 🙂
Well, I still need to do a run with the FT-817ND and my power supply at 13.8V to confirm the 5W, but for now that'll do.
Oh! And the Multi Purpose Holders worked a treat. They make the whole adventure so much quicker and easier (especially when dressed for the office). I recommend them!!
1 – The setup, and you can see the 1.2Ah (and the first use of an external speaker with FT-817)
2 – The beam pointing South West for VK3.