G90 versus FT-891 (chasing 100W)

POTA activations and the Politics of Power

It’s worth a little thinking about how boosting your transmit power affects a POTA activation. The generally unobserved and uncommented fact about POTA activations is that the activator is almost always running lower power and an antenna/antenna deployment which is lower performance than the hunter, and very often radios where absolute performance has been shaved a bit to get portability and convenience in the portable operating environment. Example: I’ve worked Larry F5PYI several times from parks, running the G90, 20W SSB into a quarter-wave vertical with radials on the ground. How is this possible? Because Larry is running 1.5KW and has a huge Yagi on a tall tower, is clearly used to working very weak signals, and he’s doing all the heavy lifting to make it work. All that’s needed on my end is being sufficiently attentive to hearing weak signals, and a willingness to work hard to get the QSO done.

In other words, it’s generally the case that it’s easy for the activator to hear/copy the hunter, and it’s the hunter who is trying to copy what might be a marginal signal. I’ve had CW contacts where the signal report I got back was 319. 319 is definitely a marginal signal. But if I’m running 10W and get a 319, if I crank it up to 100W I’ll probably get a 539k because I’m putting out 10dB more signal. The area where my signal can be heard will increase. If you’re in the PNW, that can be significant because it means that instead of the periphery of your signal footprint landing short of the Mississippi river, it’s going to land in the mid to eastern half of the US, and that means that increasing the size of the footprint gets you pretty significant gains in the number of hunters who can hear you. More hunters = a faster rate of contacts.

And for a rove, where you want to arrive at a park, set up, make the required number of contacts as quickly as you can manage, and then strike the setup and move to the next park, that’s a big advantage.

I’ve been considering more multiday POTA roves (hitting multiple parks per day, across several days), and one of the things I’ve been considering is what radios I want to take along.

Enter my problem

I’m enjoying CW activations no end. I’m enjoying QRP no end. But I also really enjoyed my multi-day POTA rove, and I want to do more trips like that. It’s also clear to me that if you want to get quick activations and then move on to the next park, what you really want is a radio that will do 100W because it affords you greater reach and therefore a larger pool of hunters who might contact you, and you really want to be able to do both CW and SSB.

Possible solutions:

• I could dismantle the station at home and take the Icom IC-7300 along.
• I could pull the Elecraft KXPA-100 out of the shack and drive it with the KX2 or KX3 (which I’d have to pull out of the shack).
• I could buy a radio specifically for this purpose.
  
• I could figure the G90 at 20W was enough power and just go with the G90

The IC-7300 would definitely do the job. The downside is that it requires pulling it out of the current home shack, which is a hassle, and while it’s not the bulkiest radio out there, it’s not something you can throw in a small camera case and lug easily to a picnic table/shelter or a table you set up somewhere in the park. On top of that, the tuner in the IC-7300 is not that impressive. You can work around the tuner issue, of course, with an external tuner. But that adds greatly to the fussiness and the size and the weight. So, not a very appealing solution.

Pulling the KXPA-100 from the shack and driving it with the KX2 (or pulling the KX3 and driving the amp with that) is really appealing, because the KX2 is a wonderful radio and the amp fully integrates with it, making it feel like just a 100W radio.
The KX3 option is really appealing because that’s the main shack radio setup and I know that radio forwards, backwards, upside-down.

The downsides are:

• again, I really don’t want to be pulling radios out of the home shack.
• The KX2/KXPA-100 combo (and the KX3/KXPA100 combo) involve a big festoon of wiring and it’s a hassle to strike it and set it up quickly. On top of that, the KXPA-100 with the built in ATU weighs 7 pounds!

All that has me thinking I’d like to replace the G90 with something compact, light, and that will do 100W, so I can use it for the upcoming season of POTA roves.

So that left me thinking pretty hard.

I bought the G90 thinking its role in life was to be the (relatively) inexpensive radio that just lived in the car all the time, with the lower cost serving to defray the risk of leaving it in the car even when it’s parked out and about. But to be honest the KX2 has become the go to radio, and I’m perpetually putting the case with the G90 in the car and then taking it back out so I can fit big stuff (like the dogs, or the trashcans) in the wayback.

Part of the reason the G90 has fallen into disuse is that, 3 dB more power than the KX2 aside, it isn’t half the radio the KX2 is, and the KX2 is smaller, lighter, more power efficient, and overall a hell of a lot nicer to use, especially when working CW. And working CW is essentially 100% of what I’ve been doing lately, because I’ve sort of fallen in love with CW.

Beyond that there’s the fact that my lifestyle and the geographic distribution of POTA parks don’t actually afford a lot of opportunities for the sort of spur of the moment park activation I’d been thinking I’d do. That means a large part of the rationale that makes the G90 compromise appealing no longer applies.

All of which boils down to the G90 no longer really has a role - it can’t do 100W, the receiver isn’t really adequate compared to other possibilities, and there are other receivers that are better candidates for the role I’m trying to fill now.

The FT-891

The FT-891 has a surprising amount in common with the G90.

(figures include G90 fan/stand)

But it must be remembered that the G90 has no built in fan - and it really needs one when running at 20W, even SSB. The solution to the fan problem that’s simplest is to get the Xiegu cooling stand for it, which also solves the problem of the G90 not having a built in bail to hold it up at a decent viewing angle. I view the stand and the G90 as a single unit above.

So the FT-891 weighs 85% of the G90, has a volume 91% of the G90.

Now, there’s one feature of the G90 that’s lacking in the FT-891 - an excellent antenna tuner with an excellent match range. In many ways the ATU is the most excellent feature of the G90.

Moving on to other alternatives, the IC-7300 has a volume 476% that of the G90, the the FT-991 412%, the FT-710 491%. So the FT-891 is substantially more compact than other options that offer 100W output.

Likewise by weight, the FT-891 weighs 116% over the G90, the IC-7300 258%, FT-991 275%, FT-710 275%. So the FT-891 is lighter than other options.

It turns out the FT-891 has a sterling reputation among field operators, both SSB and CW for receiver performance and transmitter performance as well. So there’s a lot about the FT-891 to like.

At this point I think the downsides are:

• The user interface can only be described as hostile to the unfamiliar.
• The specification for current draw on receive (signal present) is a staggering 2.0A. (but see below)
• Rather than silent PIN diode T/R switching, it uses a relay, so it doesn’t have full QSK and when keying you hear the relay clacking.
• no built in ATU

Of those downsides the one that most concerned me was the 2.0A on receive, which would really boost the size of a battery needed for, say, a three hours of POTA activation, where you’d burn 6AH just with the transceiver sitting there on receive, let alone on transmit.

I’ve done POTA roves with the IC-7300, where I put in 2 hours and 40 minutes to activate 5 parks in a single day. The IC-7300 is specced to draw 0.9A on receive, more if the volume is cranked up. So the difference would be about 1A, and over 4 hours of activation, it would add up to something like 4AH of additional battery capacity. That’s significant but not necessarily a problem.

So with that in mind, I figured I could probably work around the high idle current draw of the FT-891, and I ordered one. Interestingly, when I put it on the bench and measure the current draw, I get… 0.75A. Tuned to a signal with the volume up, it draws… 0.75A.

So in the end, with a current demand that’s smaller than the Icom IC-7300, the FT-891 seems admirably suited to the expected role for deployment when I’m doing POTA roves.

It’s worth noting: I paid $449 for the G90 (with a bunch of essentially useless accessories thrown in by Radioddity), and another $76.15 for the fan/stand, for a total of $515.15. I paid $629.95 for the FT-891, so it was a premium of $114 to get the FT-891 instead of the G90.

I know the G90 is very popular, but I have to say that I think that if you can afford that extra $114, you’d be far better served with the FT-891.

Anyway, so far I’m very pleased with the FT-891 and there are just a few things left for me to do before I’m ready to declare that the FT-891 is ready to go on POTA outings: the biggie is replacing the #$%$# molex power connector with a 3d printed housing and powerpoles - a change that looks clean and easily reversed if I need to get the radio serviced under warranty.