AM TX on FT-857D Lousy. Any suggestions?

[W4FCC]

Riley... ha!
Thanks-- I had to wait out the post-Katrina freeze, took nearly 4 months.

  Rick

 W4FCC

[flintstone mop]

There's a Ham feller in this forum, W2VW, who modified my TS440 and it gets great audio reports. The ceramic filter was subbed for one with lot more BW and the ALC was disabled. I have to make sure that the Tx is operating in a very low SWR. Im sure there were other things done, and I'm very happy with the results.
As the others have responded, there are rigs out there that have excellent audio without any mods.
G'day
Fred

[KD6VXI]

This isn't the hardest, but not the easiest.

Yahoo uses a NEGATIVE going ALC voltage, so you have to put -4 to 0 volts on the tip of the ALC plug.

Go into the menu system, change the AM carrier control to 100 percent (100 watts), then take a resistor / pot divider, and put from 0 to -4 volts on the 1/8 stereo mini-plug, using the voltage to set the carrier power.

This will allow the radio to use the ALC to set the CARRIER power, but since you have an external ALC voltage, it won't continue to act and clip the audio power.

Sounds as good as any other low level modulated radio out there.  W8JI has instructions on his website, and I think others have talked about it here.  With a D104 on my FT-857 I get good audio reports.

--Shane
KD6VXI

[W1AEX]

I messed around with my 897D (exact same PA and RCV boards as the 857 series) and found that the service menu adjustment for the ALC is a very clean way to delay the early onset of ALC intervention. John (KC8NTP) also mentions this earlier in the thread. Obviously, it is wise to save all your factory service menu settings before you make any changes as each rig has its own unique settings. If your 817-857-897 is connected to your computer, there is a free program called "Modify" that allows you to export all your Service Menu settings to a file. It's still floating around on the internet, but if someone can't find it and wants a copy, I have it here. If you mess things up, you can import that file with all your factory settings back into the radio. The program will also allow you to change Service Menu settings on the fly.

If you don't want to mess around with the Service Menu, the external ALC setup mentioned by Shane works very well with these rigs. I built one for my 897D to keep it out of ALC when using it for the digital modes, but it works great on AM as well when you set the rig up as Shane described.

The biggest problem with using the 857/897 rigs on AM is that Yaesu runs the AM signal through the 2.6kc sideband filter, allowing a maximum bandwidth of 5.2kc. I grabbed a plastic ceramic 10kc Murata filter that I had left over from an old 10 meter FM project, and installed it in one of the optional filter slots. It produced a DSB signal that was close to 20 kc wide (sounded great) while operating either upper or lower sideband, but unfortunately, you cannot select either of the optional filter slots for TX in AM mode. The only way around it would be to bypass the CFJ455K filter during TX with a cap. That would not be difficult at all, but by the time I figured this out, I had several other rigs for use on AM, so it became pointless. I ended up abandoning the project and restoring everything back to stock.

[DMOD]

I find that the only way to get decent AM on my ICOM-706MKIIG is to turn off the compressor and back the mike gain down to a "3" out of a max of 10. Setting the output power from 15 to 20 Watts gets me 375-400  Watts of power out of my Henry 2K4 so I'm happy.

That will have to do until I get my SHAFTT exciter completed.

Phil - AC0OB

[KD6VXI]

AEX,

LOVE that modify program.  MUCH better than having to blow down a complete memory map after screwing with service menu settings each time!  Saves the EEPROM, I'm sure.

I'd be interested in any other notes you have on the 897 / 857.  I love mine, ham radio deluxe makes it usable :/

Also, the ALC trick makes ALC overshoot a thing of the past... AND you can use it as an external Pout control....  Easier than menu tweakin'.

--Shane
KD6VXI

[W2VW]

Sounded fine here in NJ if that's what you were on with last evening.

I find that the only way to get decent AM on my ICOM-706MKIIG is to turn off the compressor and back the mike gain down to a "3" out of a max of 10. Setting the output power from 15 to 20 Watts gets me 375-400  Watts of power out of my Henry 2K4 so I'm happy.

That will have to do until I get my SHAFTT exciter completed.

Phil - AC0OB

[W1AEX]

I'd be interested in any other notes you have on the 897 / 857.  I love mine, ham radio deluxe makes it usable :/
--Shane
KD6VXI

Shane,

Yah, it's an amazing little 160 meter - 440 MHz station that's smaller than the lunchbox I used to carry to school when I was a little squirt. DG2IAQ (Jochen) compiled many notes on the 857/897 radios and very nicely documented them in PDF files. He has them all stored on his smartdrive which is linked to this address:

http://www.qth.at/dg2iaq/mods.htm

Jochen's squelch modification works very well and only takes a few minutes to do. It's well worth doing if you use the rig to scan the VHF air band or the FM modes on VHF-UHF. My notes are primarily about all the issues dealing with incorrect bias settings in the pre-driver, driver, exciter, and PA stages. This caused all kinds of issues with 857/897 rigs manufactured between 2004 - 2007. All that stuff is here:

http://members.cox.net/w1aex/897idle.html

It's a great little radio and very rugged.

Rob W1AEX

[DMOD]

Sounded fine here in NJ if that's what you were on with last evening.

Well thank you. I think we have found the sweet spot for AM operation.

Phil - AC0OB

[KD8PIQ]

I have been doing some reading on this tread, and would like to know if anyone can give me a link to the free program called "Modify"?  I have done some searching, but have not had any luck.  Any help would be great.  I have a NEW FT-857D, and would like to get it sounding the best I can.

Thank you for your time, 73's
-scott

[WB2EMS]

Me too!! I looked for the program but couldn't find it.

[WB2EMS]

Aha, looked at the screen shot and the web site is at the bottom. Just went there and downloaded it. 

http://www.dl4cu.de/

[KD6VXI]

I use modify myself...  If you guys have trouble getting it, I'll send it via email.  Very small, and GREAT for making modifications on the fly.  You can also use it to download a complete copy of the memory map.  Recommended for use on all the newer menu driven Yahoo rigs.

I've been using the 857 on AM for a couple days now...  Decent rig, surprises most people on AMI-West Coast..  15 watts of carrier at 6K feet does wonders.  As long as you KEEP the ALC meter from moving at ALL under full modulation, it really is a decent sounding radio.  Not a wideband Class E, but capable.

--Shane
KD6VXI

[KD8PIQ]

Aha, looked at the screen shot and the web site is at the bottom. Just went there and downloaded it. 

http://www.dl4cu.de/

I looked at that site myself, and found this on there on the download page. " Modify-function does not work with FT857D and FT897D !!!!! "

Have you tried it on a FT-857D yet?  My radio is less then a week old.  I am not sure that download right yet myself.

[KD8PIQ]

I use modify myself...  If you guys have trouble getting it, I'll send it via email.  Very small, and GREAT for making modifications on the fly.  You can also use it to download a complete copy of the memory map.  Recommended for use on all the newer menu driven Yahoo rigs.

I've been using the 857 on AM for a couple days now...  Decent rig, surprises most people on AMI-West Coast..  15 watts of carrier at 6K feet does wonders.  As long as you KEEP the ALC meter from moving at ALL under full modulation, it really is a decent sounding radio.  Not a wideband Class E, but capable.

--Shane
KD6VXI

Are you using that program on a ft-857d?  And if so and it works, I would like a copy please. And any extra info I can get would be great!  Thank you.

[KD6VXI]

I'm using it to modify my menu programs.

I've 'hard modified' the rig for all band xmit.

I <<believe>> the only thing that doesn't work is the 'softmod' version on modify, which would allow you to modify the radio for full tx, without doing any jumpers.  I've jumpered mine.

OTHERWISE, I've found NO problems using MODIFY.exe on a 857D.  Yes, D model.  I have DSP built in. (just trying to make it as clear as possible)...  Not added, it's factory (my radio came with 60 meters factory).

--Shane
KD6VXI

[KD8PIQ]

I'm using it to modify my menu programs.

I've 'hard modified' the rig for all band xmit.

I <<believe>> the only thing that doesn't work is the 'softmod' version on modify, which would allow you to modify the radio for full tx, without doing any jumpers.  I've jumpered mine.

OTHERWISE, I've found NO problems using MODIFY.exe on a 857D.  Yes, D model.  I have DSP built in. (just trying to make it as clear as possible)...  Not added, it's factory (my radio came with 60 meters factory).

--Shane
KD6VXI

GREAT!  My FT-857D is about a week old, it has the factory DSP, and 60M band.  I bought it through HRO.  If you can Email me the program you have that would be great. 

My mail is:  kd8piq@arrl.net

Thank you for your time!  73's