Thanks Robert. That’s great. Gives me a good starting point.
[quote=“VK3PF, post:17, topic:11059”]
For an antenna, you might also look at another option on the DK7ZB site:Error 404 - Page Cannot Be Found have built a variant on this antenna and have a description on my blog:
It works great on 2 m, but I have not yet tried the antenna on 70 cm, other than checking that the impedance looks OK. I use 2 sections of a squid pole for the boom, and use the remaining 4 m of pole as the antenna support.
Regards,
Peter VK3PF[/quote]
Thanks Peter. I did look at that one actually yesterday, among many of them. Hard to know which to go for!
But that area of the site is a great antenna resource for sure.
Oh been meaning to mention. Unless there is loads of activity, I’m unlikely to use 70cm much if at all.
In the period I was last active, when 2m was pretty busy, I always found 70cms dead.
Forgot to mention earlier. A few have mentioned about WAB trig points. I do have a WAB book number, assuming they don’t expire?
It’s 20 years old now probably.
And BTW, in general, here and other radio sites I have started using, it’s been awesome to see the true spirit of amateur radio and offers of help is still alive and kicking in this day and age of profiteering and quick fixes!!
Hi Steve, yes that is precisely the battery I use with my 897 and also the website that I have purchased them from. They also have a UK warehouse (although, note that you need to purchase items from the one warehouse in one order - you cannot mix and match between different warehouses in the one order), so that may make ordering easier for you.
Some people use the smaller 4200mAh batteries, but I prefer the 8400mAh batteries as they are IMO more suitable to higher power use (in my case, 80-90W when looking for longer haul contacts).
I still recommend the 3S LiPo batteries for use with the 817 as the 817 uses the same current irrespective of voltage (so the higher the voltage, the more power wasted in heat).
Matt
MM/VK1MA
Currently sitting in the Castlebay pub on the wet island of Barra in the Hebrides…
Hi Steve, yes that battery you linked to works very well with the FT-897 - I have three of them that allows me to extend my operating time when on peaks, although I find that it is rare that I need to use the second one and almost never that I need the third one (hardly ever bother to take all three of them with me).
That charger is a different brand and model to the one I use but I see no reason why it would not work just as well (mine is the Turnigy accucel 6 which looks to be 12 quid cheaper than the Imax one).
With the 5.5mm bullet connectors, I cut them off the first battery I bought and with a lot of stuffing around put some 45A Anderson connectors onto them - not something that I would recommend as it was a bit of a butchers job on it to make it fit. You can get rather cheaply from hobbyking the “5.5mm Bullet-Connector to TRX Compatible plug Battery Adapter (2pcs/bag)” - I cut off the TRX plug and installed Anderson power plugs to the other end of the bullet connector adapter which being smaller guage wire much more easily take the Anderson power pole connectors. Pretty much all of my gear now uses Anderson plugs - makes life so much easier for me!
No problems Steve. Yes the Accucell6 is DC only input - so I picked up a 2.5A 12V output plug pack that I use to power the charger. An extra item needed, but as a whole it is quite flexible - I can use it in the car from either the car battery or the inverter, I can use it travelling (both O/S and domestically) and I can use it at home. Everyone’s needs differ, so if AC power input is needed, then the other charger is probably better suited for your needs.
Hi Matt,
After spending a lot of time on antenna research and poles etc, I am about to order some battery kit.
Typically how long and at what power/mode do one of these batteries last on your 897?
It seems the charger I selected is only available at the “International Warehouse”, which judging by the photos is USA looking at the mains lead?
So I assume I won’t get a UK cable.
What would be another UK hobbyking supplied charger suitable for the battery quoted ((8400mAh LiFePo4) ?
Edit: they don’t seem to do a UK one. Adapter it is then by look of it.
Edit2: Gone for the items suggested by Matt including the DC input charger.
Hi Steve, using the 4S LiFePO4 batteries (8400mAh), I generally get around an hour to hour and a half at power levels up to 80-90W on SSB. I monitor the power used (using a watt meter inline) and try not to use any more than about 5.5Ah to 6Ah from any one of the batteries.
Thanks Matt, that’s encouraging. I was thinking of using 40-50W keeping a little in hand if needed for that pesky QSO.
I take it watching the voltage on these isn’t much of an option to monitor drain, as they hold up well to the end don’t they?
Just a little word of concern, a fully charged 4S LifePo will deliver up to 16.8 volts albeit for a relatively short period. I would have thought that was outside the spec for the 897, there’s an article somewhere about using high power diodes to drop the voltage initially then auto switching them out of circuit when the voltage drops to a suitable level. If I can find it i’ll post a link.
Need to be careful to distinguish between Lithium Polymer (LiPo) and Lithium-Iron Phosphate (LiFePO4) chemistries.
Fully charged voltage for a LiPo cell is 4.2V so 4S would be 16.8V. However for a LiFePO4 cell the maximum voltage is only around 3.6, giving 14.4V for a 4S battery which is OK for nominally 13.8V radios. The plateau voltage for LiFePO4 cells is 3.2 so for most of the battery’s usable discharge period voltage is around 12.8, which is fine for the FT857/897 (and many others)
You’re quite right about using a string of high powered diodes to “tame” a 4S LiPo to run a 13.8V radio - it was the standard technique before LiFePO4 became readily available. (The idea was, placed in series with the supply, forward biased they provided a voltage drop of around 0.6V per diode, you just shorted them out as the terminal voltage of the battery dropped as it discharged). Never saw an auto version though, that would be less fraught with danger…
Never tried it myself - my trusty 817’s are very happy on 3S LiPo’s and I’m not about to cart my FT101 up a hill
