Yaesu has it wrong! FT-891 RX/TX Current Test

Discussion in 'Amateur Radio News' started by OH8STN, Mar 13, 2018 at 3:45 PM.

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  1. US7IGN

    US7IGN Ham Member QRZ Page

    But why? It is small and light. Today we have very small and powerful LiPo (LiFe) batteries and power consumption is not so critical as earlier.
    KK5R and WD0BCT like this.
  2. KE0CAA

    KE0CAA XML Subscriber QRZ Page

    We have noticed this with most of the specs coming out of Yaesu in the last couple of years they were pulling the worst case that they could get from testing rather than posting averages with % deviations.

    As far as portable goes I would say its what you make of it. I have a LiFe pack that will run the FT991 and a laptop for a day that I could easily carry in a pack on a strong back for a few miles ;)
  3. N8DAH

    N8DAH XML Subscriber QRZ Page

    Had a 891 for almost a year. Did field day with it, 3 contests (not a big contester) and a bunch of portable ops. Radio was nice did what it said and had a great front end. I did end up selling it and getting a new base rig all the same. I am working with QRP only for my portable ops now but that's just me.

    New or used for the price its a good radio.

  4. W1PJE

    W1PJE Ham Member QRZ Page

    Hi all,

    Just a FYI that some FT-891 rigs have major digital noise problems if you are leaning toward digital portable operation or weak signal work when you use CAT control. This may or may not be relevant to you depending on your application and whether you receive a rig with the problem. See this exhaustive QRZ thread for more information. Discussions on the problem begin midway through page 18:

    K0PIR and KK5R like this.
  5. K3FHP

    K3FHP XML Subscriber QRZ Page

    Julian, Good work, as you always do(I admire your fortitude and skill in the field), but there is no reason to lament over the xmit current drain of the 891, it IS NOT a QRP rig in design and does what it is supposed to do. I know of no qro rig that does not draw higher than qrp rig level current even at 5W or less because you are running the qro xistors(designed for over 5w) at reduces drive but they are still higher powered units. If you want loq power consumption you will need to bypass and disconnect the qro xistors or, more reasonably, use a qrp design to begin with. Nothing wrong with you or ths fine rig, just not what it was designed for. I still marvel at my KX-3 with a fine SDR and front plannel features drawing .184A on receive and 1.3A at 5W. I might add that my OHR-100 is also a fine working rig designed for qrp and is .050A on recv and 1.1A at 5W. Different designs, features and PRICES or whatever raises your flag. Ain't ham radio wonderful.


    K3FHP Dave
  6. KF5FEI

    KF5FEI Ham Member QRZ Page

    I seem to recall my 817 having the same issue when I was doing satellite with HRD controlling the frequency.
  7. KK5R

    KK5R Ham Member QRZ Page

    I built the HW-104 and SB-104 which was essentially a 100w rig but they had a HI-LO power switch on the front panel. When in LO power, the signal to the antenna was not taken from the final amplifier, it was taken from te output of the PA driver board. Such an option should also be on today's HF rigs where they are used for QRP.

    The 104's on LO-Power had the option of going down to One Watt...

    Also, the concept that Elecraft has where you basically buy a QRP radio and add power modules to it seems a good approach. If a QRP purist wanted to make sure to run low/QRP power, no decisions have to be made (and it's cheaper...). If higher power is wanted/needed, then the appropriate module can be bought and installed.

    The question of receive idling current is still there, though. Some radios have a way to turn off the lighting on the dial but with some new displays, this does not recover much power. Tuning off the display has inherent problems to it where we tend to constantly look at the display land have problems seeing small details without optics.

    Options? Typically, imagination is what limits options. With unlimited imagination, whatever is logical and can be done is then limited only by the manner of implementation.
    Last edited: Mar 15, 2018 at 5:24 PM
  8. NX1Q

    NX1Q Ham Member QRZ Page

    Meh, you are modest is all.

    I am not familiar, but seeing you are quite experienced with QRP, it makes me wonder what the draw is at 5 watts on the Yaesu 817 since you mention the 5 amp draw at 5 watts with the 891.

    Hmmm...silly little qrp rigs...amps are for kids.
  9. WE7H

    WE7H XML Subscriber QRZ Page

    Hey Julian,

    Thanks for the good words. And thanks for doing the fast follow up vid. The busy receive power consumption was higher but not by very much. Never got close to 2 amps...didn't even bust 1.2 amps. Not too shabby. And you had the volume up where you would probably never run it with digi sigs. Just tell me you didn't blow your speaker! I imagine speech would have been less. As for the headset, since we know what driving the larger speaker was doing, should be fairly safe to say the headset audio would draw less also.

    It was interesting to see what the various actual current draws were under the various working conditions, RX and TX based on your set up in the two vids. Maybe if your voltage was dipping some you might see an increased current draw before you got to a low voltage cut off and/or possibly getting squirrley equipment behavior. And at that point you're probably pretty much done anyway...ready to go to a spare batt, QRT, QRChow or something. For ops on those long nights, I'm sure you have to make the best of charging opportunities during the high lat winter days especially.

    Thanks again Julian for posting these vids, I'm sure you've helped a few folks out that were wondering about this. Like I said before...that's where the rubber meets the road...or...Yes, my lab IS in a tent! Myth Busted (in practical application). Good on ya!!!

    Stay Safe in the field, Stay Warm and keep up the good work and have fun doing it,

    Ed, WE7H
    OH8STN likes this.
  10. K9CQ

    K9CQ Platinum Subscriber Platinum Subscriber QRZ Page

    I have had the 891 for quite a while now that I use mobile in place of the 857. I also have a 991 that I have used mobile as well. The biggest thing that I have noticed is the 891 noise reduction is much better than the 857 and even better than the 991 is when ran mobile. I have a route that takes me by some HV power lines for about 10 miles that would make the 857 and 991 unusable. The 891 gets the noise in it but the filtering still allows me to make contacts through that stretch of road. I think it's the best of all of the small low priced HF rigs on the market today.

    Tim, K9CQ
    K0PIR and OH8STN like this.

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