My first HF transceiver

[Hutch]

After a lot of study, agonizing, deciding, undeciding and final, this is IT resolution...

I bought a Yaesu FT-857d, plus a Signalink USB TNC.  These seem to figure prominently in folks' EMCOMM kits.  Glad that decision is behind me.  I plan to build my home station in an audio gear travel case.  (One with wheels and a pull-up handle).  This will allow me to take to the field with the same kit I operate at home.

This gonna be a lot of fun!

Thanks for letting me share.

[Rescue9]

Nice pick. I wish I'd have gotten the signallink myself, but I bought the wholphi instead. Now its just a matter of building my own cable to work with my KX2 as well as the 857d.

Once you get the 857d up and running, take some time to really work the system out. You'll find that there are "issues" in how it operates that will annoy. The 857d is a good emcomm & first radio in my opinion, but make sure you pick a second radio based upon the features you want that the 857d is missing.

I'm a QRP guy and hiker so I wanted something smaller, lighter, and used less power. Naturally I bought a QRP radio as my second setup, only to sell it for a smaller but more feature packed QRP setup.

[cockpitbob]

I've had an 857D for years and love what an all purpose radio it is.  It's my home base station and for long trips goes in my car.

I recently hooked up a Signalink to it and got on the air quickly with Digipan but haven't figured out how to get FLdigi to work with the radio yet.  It won't Tx or Rx.  I may give it another try today.  If anyone has a lot of experience with an 857D and Signalink I would love to hear what settings you use.

[gil]

I bought the wholphi instead. Now its just a matter of building my own cable to work with my KX2

Hello Rescue9. I want the Wolphi for my KX2 as well, what did you have to get to build the cable?

Gil.

[Rescue9]

I haven't built the cable yet. I don't figure it will be too hard. I purchased a 3 pin mic/phone to 4pin splitter. Now all I have to do is sacrifice one of my 4pin cables and solder a 6 pin din on the end.

I was hoping that I could just run the split direct from the radio audio ports to the tablet, but forgot about the switching necessary to activate the mic function on the tablet.

I'll post pics of the process soon. Think I'm going to build one of those earchi 9:1 as well. Have you found it necessary to run the guanella inline with the earchi?

[gil]

Have you found it necessary to run the guanella inline with the earchi?

Hello, the Guanella BALUN and the EARCHI are for two different things. The Guanella is for an off-center dipole, 4:1 BALUN. The EARCHI is a 9:1 UNUN to feed a wire from the end. So, there are really no relation between those two, different tools for different antennas.. I can't even imagine how one could use both on the same antenna... A dipole is balanced, a long wire is unbalanced, while coax to the radio is unbalanced, two different problems, hence the two different solutions.

Gil.

[Rescue9]

That is for the information Gil. I still don't understand fully antenna design and theory. That explanation helps out lots.

[gil]

I am no expert either... The best thing is to build lots of them :o

If I understand the Guanella well enough, it not only divides the impedance by 4, but also limits the common more current (RF) returning to the radio, and does that better than a regular BALUN. The EARCHI UNUN just divides the impedance of the wire by 9. The coax outer shield acts as the counterpoise, needed since the wire is not a half wave. If the wire was a half wave, as in the end-fed half-wave, half of it would be the counterpoise. If an RF choke is used on a "random" wire antenna's coax, better put it near the radio. On an EFHW, it doesn't matter..

The off-center dipole, or Windom, is not fed in the middle, so you have a higher impedance to deal with, hence the 4:1 transformer. You also get common mode current to get rid of, and a dual-core Guanella BALUN does that well...

That's the problem with feeding an antenna with coax, which has a very low impedance... Better feed an OCF dipole or multi band doublet with ladder line, in which case the tuner can be near the radio and you still have minimum losses. Feeding a high impedance antenna with coax with a tuner near or in the radio is a losing proposition. It is much better when possible to place the tuner at the antenna feedpoint, or better yet, use a resonant antenna and no tuner. A regular coax fed dipole without a 1.5:1 BALUN should really be fed with 75Ohm coax going into a tuner at the radio, no problem there.

If what I believe is right, to naturally not get "RF in the shack," you must feed the antenna either in the middle or at the end. Anywhere else and you get common mode current. That is why "random" wires can be such a PITA.

Personally, I prefer end-feds. The impedance transformer does induce losses, but not enough IMHO to offset the convenience of deployment, and you don't need an RF choke. You're not going to feel pinpricks in your fingertips when keying Morse on a metal key... For my fixed location, I opted for a Windom, but for portable, end-feds rule!

Anyone please correct me if I'm wrong or my information is incomplete...

Gil.

[RichardSinFWTX]

An excellent choice, Hutch!  I've got the FT-857D, SignaLink, an LDG Z11 Pro II tuner and a 30A power supply all built into an army surplus medical supply case.  It also houses my accessory case, laptop, foldable solar panel and other cables.  This weekend I ran a length of RG-213 from the eave of my roof on the back of my house across my attic and down a wall so I can "play radio" (as my wife calls it) in air conditioned / heated comfort!  I can also take it to the field and operate from the bed of my truck

Shoot me a PM and I'll be glad to send ya some pics of my setup and answer any questions you might have!

[Hutch]

Woo-hoo!  Thanks, Richard.  I'm struggling a bit in my wish-list for the box.  I'm looking at 30-amp power supplies, and I'd like to dial the voltage a bit, as well as have digital meters for both volts and amps.  In addition, I have  15-AH LiFePo4 12v pack ordered, and I also want to be able to attach to external 12v batteries via something resembling a set of jumper cables.  I'd really like a 3 or 4 position rotary switch to select the power source, but most folks who blog or YouTube about their EMCOMM kits are a little thin on these sorts of details.

PM's coming.  Thanks again.

[gil]

Hutch, make sure you get a low voltage alarm that monitors each cell for your LIPO pack.. Never let one go below 3V!
Gil

[Hutch]

Good coaching, Gil, thanks.  It's assembled by Bienno, which seems to be well thought of.  It is described as having a BMS integrated into it, and they are also providing the charger.  I considered using the power supply to charge the battery, but quickly realized that if the power supply is online, I have AC with which to supply the charger. (Duh).