FT-897D recieve power

[KE7HQY]

I was curious if any FT-897D owners out there have ever measured the power drain on RX (with low audio output) when it's on external power mode (12v source). From the manual it says ".6-1 A", which is a fairly good for "Mobile" shack-in-a-box radios. Example a IC-706MKIIG is 1.8-2.0 A just running RX.

Anyone have any real world numbers on RX power draw from external power (not internal batteries)?

-73 de Anthony, KE7HQY

[KC0BUF]

I thought for a second that you were going to ask how many watts of receive it had, and I died inside a little.

[KD6NIG]

I'm not sure, I'll have to check. I know that when I run my 897D, FT8800, and scanner at home with my LED light on that my amp meter shows 1.78-1.82 amps being used. (@13.78V)

Never tried it by itself to be honest.

[AG3Y]

Ah, see, one of the differences between a "true" QRP rig, and a mobile rig with the power cut all the way back. A true qrp rig can run for a week on a set of D cells, or a jell cell, but you could never do that with a mobile rig drawing 12 watts in receive with the volume turned down !

73, Jim

[W7WV]

I never acutally measured mine, but I did lock up the MH once and leave it on by accident. A week later the two house batteries (120 AH each) were both fine. The motor home was not plugged in.
I think the AH-4 was powered too as I think when the radio it on it's hot too.
I suppose if you are really curious I could go measure it for you. Send me an email if you want me to measure it for you.
I think I can still handle a simple current measurement! ;)

[N5USR]

I don't have an 897, but my 857D (which should be pretty close) is fluctuating between 0.59A and 0.63A, whether squelched or listening with the volume down low.

That according to my "Watt's Up?" meter - I've been plugging everything I can find into it, just to see what it'll read! :D

Edit: Wow! Got to thinking about that nice, bright display and just checked the draw with the display lights off. Dropped to 0.53A! The different display intensities only make about 10mA difference, but turning it off is definitely noticeable.

[KE7HQY]

thanks to N5USR and W7WV for your readings. I did some "watt" testing on my 706 and I can't believe my eyes. Its running 2.6A just sitting idle (squelch or no!).

I have a "Kill a Watt" watt tester that I plugged my power supply in. I just ran a simple radio off, radio on test and subtracted the off power from the on to get only the radio's reading - 36 watts! @ 13.8v that is quite a load.

Anyways, I'll definitely have to consider the FT-897D for what I'm intending to use it for, which is portable with gel cell batteries. I could go with a QRP rig, but I like the option of bumping the power up to 50+ watts without an external amp.

[N5USR]

I have a "Kill a Watt" watt tester that I plugged my power supply in. I just ran a simple radio off, radio on test and subtracted the off power from the on to get only the radio's reading - 36 watts! @ 13.8v that is quite a load.
Remember, though, that you are on the other side of the power supply's inefficiency with the KillAWatt. So your 36W includes the losses in the PS as well. If you are using a switching supply, it won't have much, but a linear supply is (IIRC - can't remember much this early in the morning...!) maybe 60% so you can subtract 40% of that value to get just the radio's portion. So around 22W, which is still over 1.5A. And - humorously - this is one case where the more efficient the supply is, the worse the news is! :)

[KE7HQY]

how could i have forgotten PS efficiency rating? Yes, that makes a lot more sense. I have a very old industrial clunker (i.e. not terribly efficient).

I finally got it right and pulled out my multimeter and measured the output amperage to the radio from the power supply - 1.44A, which means my power supply is 55% efficient, not too good.

That is still almost .8A higher than the 897D, which can be quite a bit when running off batteries.

[WA9SVD]

I thought for a second that you were going to ask how many watts of receive it had, and I died inside a little.

Probably 2-2.5 Watts.:rolleyes:

[W7WV]

For those interested he sent me an email and I measured mine from charged batteries in my motor home at .68 amps with the audio loud enough to hear it from the batteries 15' away.