Portable Operation

I Bought a Kenwood TH-F6A

Monday was my birthday and so I decided to give myself a birthday present of a new HT. I researched all the high-end HTs and decided on the Kenwood TH-F6A.  My decision-making process was something like this:

  • Because I also have a Kenwood TS-590 and TM-D710, I was inclined toward the Kenwood HTs because of the similarities in user interface.
  • I quickly ruled out the Icom’s because the only extra feature they offer is D-Star and I have little interest (no interest, actually) in D-Star.
  • The Kenwood TH-D72 is pretty much a hand-held version of the TM-D710 that I already have so I would not be gaining any additional functionality/capability.
  • The Kenwood TH-F6A also operated on 220 in addition to 2M and 450. I thought it might be fun to play with that.
  • The Kenwood TH-F6A will receive DC to Daylight (actually 100KHz to 1300MHz). I occasionally need to be able to listen to my TS-590’s transmit signal on another receiver and the TH-F6A would make that pretty convenient.  Being able to use it as a portable SWL receiver (as well as AM and FM broadcast) is also a big plus for me.
  • I dismissed the Yaesu VX-8DR simply because $420 is more than I wanted to spend.
  • The Yaesu VX-7R was interesting for it’s 6M capabilities but other than that it would not do anything for me that the Kenwood TH-F6A would not.

Thoughts Now That I’ve Owned and Operated it a Few Days

First, no regrets.  I still believe I made the correct choice.

Intuitive user interface is important to me.  Maybe it’s because I’m an older guy and grew up in an era when radios had knobs and switches, but I have this rule:

If I’m broken down on the side of the road, can I pull the radio out of the glovebox of my car after not using it for six months and figure out how to operate the major functions (volume, squelch, frequency, offset, tome, memory) without looking at the instruction manual?

So far the Kenwood TH-F6A rates five stars in this regard. I suspect that it’s because I also have the TS-590 and TM-D710 so I am used to the ‘Kenwood way’.

After doing some reading online, I replaced the stock antenna with a Diamond SRH320A for improved performance, both in transmit and receive.

The TH-F6A is able to monitor my TS-590’s transmit signal here in the shack.  Otherwise though the HF sensitivity is pretty poor. I can’t even receive WWV.  The next step is to rig up a long wire antenna for it and see what happens.

I originally thought its small size would be a problem but it actually fits very comfortably in my hand.  Ditto for the buttons. They are spaced far enough apart that I’m able to punch the button I want with no difficulty.

Kenwood TS-590 Current Draw Measurements

After last weekend’s adventure taking the TS-590 out in the field, I started thinking about operating ‘picnic portable’.  The TS-590 is a really nice little compact radio and lends itself well to setting up at a remote location that does not require schlepping my gear for long distances. But how much current does it draw? What battery capacity will I need?  I decided to find out.

I have a Fluke 23 DMM that supposedly will measure DC current up to 10 Amps.  Probably not enough. What I needed was a shunt.  I love it that all the big electronic component supply houses are now on the internet. It took just a few minutes to discover that Newark has just what I needed, so I ordered one.

It arrived and I rigged up a quick wiring harness that would attach to the TS-590’s power cable (I love Anderson Powerpoles) and a 7.5Ah gel-cell battery.  This is what I found:

Output Power Amps
5W 8.4A
10W 9.0A
15W 10.2A
20W 11.4A
25W 13.2A
30W 13.8A
35W 14.4A
40W 15A
45W 16.2A
50W 17.4A

Some assumptions:
1. Using the discharge curves for the average gel-cell, I can really only use about 60% of the batteries capacity (in Amp-Hours) without damaging the battery.

2. I’m assuming 50% transmit and 50% receive.

If I operate ‘picnic portable’ at the 20 Watt power level then I need about 9.5Ah of battery capacity for each hour of operation.

BatterySpace.com has a 12V 20Ah SLA battery for $37.85 that would give me 2 hours of operation, which seems like a reasonable number.

QRP Portable Session 2

Undeterred by yesterday’s lack of success, I decided to try again today but shift my tactics a bit.

Last night I remembered that Thunderbird Park is not far from me, and there is an elevated spot with a covered ramada (shade!) that you can drive right up to and park.  No shlepping gear up a trail! I also decided to take both the KX-1 and the TS-590. My 7Ah gel-cell would provide a couple hours of operation  of the 590 and I could do a quick comparison of the two radios.

I left the hours at about 6:15am and by 6:45 was set up and operating.

Lesson 1: This non-huffing-and-puffing version of QRP operation is a lot more enjoyable.

Once again however, I could hear but know one could hear me.  I answered several CQs.  I called CQ myself several times. I tried both CW and SSB with the same (lack of) result.

I alternated between the TS-590 and the KX-1. Both rigs seemed to hear just as well. As long as the band is not crowded I think either rig will work just as well. Of course if the band is crowded or there is a lot of QRM the TS-590 with it’s DSP will run circles around the KX-1.

Lesson 2: I have a lot of learning to do. THis Saturday AZ ScQRPions are putting on a QRP conference in Flagstaff.  I think I will go.

Lesson 3: My CW speed needs to get to about 20wpm.

 

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