KX2 internal battery or not

Equipment Radios & Power
21

I recently played with an x6100 and it was surprisingly good, but it really is a brick!

I’ve had my KX2 since 2017. Love the ATU, love the internal battery. You can get a higher capacity internal battery (3.5Ah vs. Elecraft 2.4Ah) for less money. I like the internal charger, but only recently got one… taking the battery out isn’t a huge deal but it did eventually cause the speaker connector to become intermittent (easy fix). I like having the real time clock that stays set to the correct time and I don’t have to mess with it!

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22

Yes to internal battery, side protectors, internal ATU. 3S 18650 are widely available without handing £80 to Elecraft. Opening and closing the case is not an issue. The radios are robust and well made.

Yes to a mic. Make one for £5 using this simple video:

Or buy this little beauty for £20

No need for up and down channel keys at the moment due to a bug in the firmware, which elecraft seem to be in no hurry to fix.

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23

Internal battery? Of course!
Use a nominal 13+volt external battery; when much of its capacity has been used, and its voltage drops to just below that of the internal battery, the latter starts supplying the energy.
Backup / increased capacity for external battery, and automatic changeover.
What’s not to like? The internal battery is occasionally used; I top it off a few times a year.

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24

Am I the only one whose KX2 puts out not more than 7W on 10m with a fully charged internal battery? Full 10W on an external LiFePO4.

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25

Carlo, I get:

12 watts with external LiFePO4
10 watta with Li-ion (internal and external)
7-8 watts on 10m band

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26

Thank you Fraser, you were faster than my correction. Glad it’s not a fault of my unit.

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27

Thank you Fraser, that, along with the power comments that follow (external battery == more TX power) pretty much makes my mind up.
Start with an external battery and if i ever need/want an internal battery, a 3s 18650 with protection circuit will do the job and easily found/put together. The mic option looks awesome and fits under the “not too concerned if it gets accidentally trashed” price bracket.

Wait - why does the external LiFePo4 give better TX power than the Li-ion, slightly higher voltage - 4 cells vs 3 ?

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28

There was a firmware update that would give 12 watts when a higher voltage battery is used. It is described as being suitable for search and pounce rather than working your own pile up, due to the extra heat generated in the PA. To be fair, the KX2 will sometimes throttle back on a really warm day when using the internal battery. This only happened to me once.

12w v 10w v 5w. You’ll be surprised how little difference it makes to your signal reports.

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29

And another vote for the side plates and cover (I think they should be standard personally); internal ATU (it increases my options for antennae); and the internal battery.
I normally use an external battery, with the internal battery just keeping the internal clock going. However I have used the internal battery for light-weight activations and when carrying my radio on aircraft. An internal battery saves any possible hassle at airport security in my experience.
2 issues with my KX2: the clock usually needs adjusting to the right time after a week or so (which admittedly negates the point of maintaining it on the internal battery) and my set sometimes drifts off frequency slightly during use. I then have to manually adjust back to the correct indicated frequency.
It’s a pity it’s not waterproof and cheaper :wink:, but otherwise I love the radio for its performance and light weight.

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30

I enjoyed reading this thread, I am torn at the moment between a KX2 and the Discovery Labs 599. The general performance of the KX2, ability to have an internal atu and battery are appealing. However, it’s ruggedness and being rainproof are a big plus for the 599, it’s available now and cheaper than the KX2. No atu though and the battery “holder” is £499, batteries not included!! 599 is a new radio from a new manufacturer, so that may be a pitfall on its own, compared to the renowned aftersales service from Elecraft. Decisions, decisions.

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31

Transparent plastic bag solves the rain problem.

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32

Regarding the heatsink: someone on the reflector had suggested you can use a beer carton to shield it from the Sun, I can attest it works perfectly and can be adapted to other portable rigs in your possession.

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33

Does the displayed frequency change during use? If so and you are using the microphone, make sure you disable the Up/Down buttons in the menu. There’s a software bug that the radio can misread the buttons and it bumps the frequency up or down. Until there’s a fix, in the menu “MIC BTN” switch it to just PTT.

Another vote for the internal battery and charger. I like to be able to topup the battery whilst on holiday in our campervan where space is limited and not having to have bits of KX2 lying around is just a lot more convenient. However the internal charger isn’t a difficult install, so could be fitted later if that fitted your budget better.

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34

Thanks John, I’ll try that

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35

This thread was mentioned while I was on a summit today… and i had to admit that I was on 5w internal battery as a bail-out becuase I forgot the link cable from my Xeigu to my external battery.

I guess another reason why they are useful :slight_smile:

36

Not that new - I have been using mine since at least October 2021. Excellent either with a linked dipole (no ATU) or EFHW with the T1 ATU which will also tune a short bottom loaded whip used recently for 20m…
73,
Rod
Edits
I have not used any other radio for HF activations since then.
T1 not necessary for the whip if you get the length right!

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37

I spoke with Tim @G5OLD earlier today during his activation of G/SC-004 (Staple Hill) and we had a brief chat about his post.

As people already mentioned, everyone will have an opinion on the matter based on their experience, needs and operating style.

I am fortunate and have a KX2, KX3, FT818 and Lab599 TX-500 all used for SOTA.
Except for the TX-500, I can use an internal battery with the others, but I always use an external battery as it allows me to activate multiple summits during a day/weekend without the need to re-charge or worries about how long I can still operate without a re-charge.

When on a summit, especially in windy weather, I am struggling with the speaker on the Elecrafts and find them underpowered. I read this before but it may just be me.
Both have the ATU but since I use resonant antennas for SOTA, they’re a nice to have but not a must have for me.

I haven’t tried a Chinese radio yet (mainly since most of the people I know moved away from them).
I don’t spend large part of a day on a summit, chasing DX or S2S, so I have not found the need for a nice display with bandscope such as the 705.

What I like most about the TX-500 is the form factor, ruggedness, being splashproof, very little or no tweaking needed from activation to activation and being able to display a chart on screen to check for lowest SWR in the band.

The KX2 is a fantastic radio and is a dream to operate, and I am sure you’ll be very happy with it like most KX2 owners but if I could pick only one radio for SOTA, I would pick the TX-500 each time.

But to get back to the original question, an internal battery is nice to have especially if you have the charging unit for the KX2, but I prefer operating with a bit more juice for multi-summit days/weekends hence my preference for an external battery. The internal battery can then always function as a back-up; just in case…

Good luck!

73, Robert

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38

Yes same for me. The headphones output is not loud either. I have an audio amp to build over Christmas to drive headphones louder.

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39

ATU - Yes! Worth the money. You never know when you’ll really need it.
Side KX rails and top - Yes. Easy mod, 30 minutes max. Has already prevented damage to radio several times.
KX2 stock battery - ok. I use the Bioenno LiFePo4 as the KX2 battery developed a short I’m unable to diagnose.
External mic - The link MM0EFI Fraser posted is what I use. We built about four of these in a couple hours. Fun, easy project and much less weight than the stock mic.

Merry Christmas.

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40

Andy,
Or just buy amplified headphones. Neater. Faster to get.
But always make sure they are charged.
73
Ron
VK3AFW

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