yaesu 757gx

[mtraxler]

I have recently acquired a yaesu 757 gx. I also have the power supply and the antenna tuner with it. I purchased a 811h amplifier. however when i plug in the arb704 and connect it from my radio, it automatically starts transmitting. once i unplug it turns off. does anybody know exactly what I should do and what connections I should use behind my radio as well as the arb704. Thanks for the help. 73, Mark W9AXX

[wx1f]

Sounds like the 757GX amp relay control is shorted...so it is permanently keyed. Have your tech check it before you fry something else.

[WA9WVX]

Hello Mark,

When you purchased your Yaesu FT-757GX H.F. Transceiver, Power Supply & Antenna Tuner, Did they supply you with a copy of the Operating Manual?

If you don’t have the Yaeso Operating Manual, here’s the website link:

http://www.foxtango.org/ft-library/FT-L ... -757GX.pdf

While I’m at it, here’s the website link for the AmeriTron ARB-704:

http://www.ameritron.com/man/pdf/ARB-704.pdf

Once each one downloads, copy them to your computers Harddrive and you’ll need either Acrobat Reader or FoxIt to open the PDF files.

Pay close attention to Pages # 18, 19 & 20 for the Yaesu Box Level Interconnection Configuration Diagrams.

I believe your Ameritron ARB-704 Interconnection Box should connect between the FT-757GX H.F. transceiver & the Ameritron A-811H RF Amplifier in lieu of not having a ‘FRB-7’ Interface. A Special Note regarding the Linear Switch located on the rear of the transceiver Should Be in the ON (Depressed) Position since you also have the Yaesu FC-757AT Antenna Tuner connected to the H.F. Transceiver.

I was wondering “if” you purchased the Plug & Play Interface Cable Kit when you purchased the Ameritron ARB-704 Box or did you build your own interface cables?

73,

Dan
WA9WVX

[mtraxler]

Yes, I got the manual that came with it, however, a friend of mine said that the 704 would not work with my radio and now I am not sure what to do with it. I am going to have to try something else. Yes, I have the plug and play camble that came with the arb704.

[WA9WVX]

Hello Mark,

When you purchased your AmeriTron ARB-704 & PNP-8D Plug & Play Cable Kit, You probably assume that the cable kit would be compatible with your Yaesu FT-757GX H.F. Transceiver -- NOT! and here’s why. The AmerTron PNP-8D Plug & Play Cable Kit ONLY List the following Yaesu H.F. transceivers: FT-1000 Series, FT-900, FT-920, FT-990, FT-747GX & FT-767GX – There is NO mention of the FT-757GX Series for a Good reason, the Band Data Plug Pin Outs & Functions are NOT Compatible so your Friend IS correct.

FT-747GX

Pin & Function

# 1 +13.8 VDC
# 2 Tx Ground
# 3 Tuning Control
# 4 A
# 5 B
# 6 C
# 7 D
# 8 LINEAR

VERSUS

FT-757GX

# 1 Ground
# 2 D
# 3 C
# 4 B
# 5 A
# 6 Tx Ground
# 7 +13.8 VDC
# 8 Inhibit Receiver

You do have an option to contact Yaesu, USA listed below:

Vertex/Standard USA (YAESU)
10900 Walker Street
Cypress, CA 90603
1 (714) 827-7600 (This is the BEST method)

Order the following Cable Kit T9101295A Band Data Cable & Plug Assembly and/or the FRB-757 Relay Control Box Part # D3000280 for connecting to a QSK RF Amplifier.

You may be required to Depress the Linear Switch (on your FT-757GX Transceiver) to the “ON” or "OFF" positions.

Refer to your Yaesu Operating Manual for this Switch and Box Level Wiring Configuration.

BTW, unless you are a High Speed CW (Morse Code) Operator (at 20 WPM or faster), you’ll never see the difference on AM, SSB or FM Voice Communications by having the QSK option.

The AmeriTron 811H RF Amplifier uses a Tx Low or Switch to Ground to Enable the T / R Relay. Do not forget to connect the ALC cable between your RF Amplifier and the Transceiver to prevent SSB Flat-Topping and/or Splatter on the H.F. Bands.

It is Essential to provide a Good Ground to each piece of equipment and connect the # 10 or # 12 A.W.G. Green wires to a common (Earth) Ground Rod as close to the equipment as humanly possible.

73,

Dan
WA9WVX

[mtraxler]

Dan:

thanks for that information, I will contact them Monday....

73's

Mark

[mtraxler]

Dan:

Yaesu doesn't have that frb 757 relay box, however, they do have the band data cable which I ordered. Will that correct my problem that I have and will that be enough to get the amp going??

Thanks,

Mark

[w5rkl]

Dan:

Yaesu doesn't have that frb 757 relay box, however, they do have the band data cable which I ordered. Will that correct my problem that I have and will that be enough to get the amp going??

Thanks,

Mark

I don't know if your FT-757GX to amplifier interfacing issue has been solved yet or not. If it has then disregard this post.

I do not recommend using the band data cable to control your amplifier.

Since you have the FT-757GX operator's manual, turn to page 19 where you will see the FRB-757 interface schematic. As you can see the circuit has 6 components, a relay, 3 resistors, a transistor, and a diode.

Duplicating the circuit is very easy. I duplicated (built) the FRB-757 using simple, easy to obtain, components. I used a 12VDC relay purchased from Radio Shack and the other components came from my junk box. The cables are simple shielded stereo interconnecting cable found at Walmart, even Radio Shack has them. Total cost, less than $10. Construction time, one hour or less, depending on your building skills and experience.

Again, I do not recommend using the band data cable to control your amplifier.

73's
Mike W5RKL

[mtraxler]

Dan

No it hasnt been fixed yet and my building skills are not up to par for building this. but you are more than welcome to help me and I will pay you for your time as I would have to pay to get one. I hate to have this amp sitting here collecting dust. but maybe one day I will get a radio that I can use that isnt 25 years old. I am going to try and get one in the near future but I would like to have had this one working. Thanks for your expertise and help in this...

[WA9WVX]

Hello Mark & Mike,

I'll start digging through my parts drawers for the required components and a project box with RCA phono jacks for the Inputs and Output(s). Mike's probably correct about the time it will take to homebrew a FRB-757 Clone Interface Box.

I agree Mark, it would be a pity to not be able to use your AmeriTron 811 H RF Amplifier with your Yaesu FT-757GX H.F. transceiver. Oh BTW, the FT-757GX transceiver is still a very good transceiver to own in regards to the age of the unit.

73,

Dan
WA9WVX

[mtraxler]

Ok, thats great. I will pay for anything that you use. Just let me know.......

Thanks,

Mark
W9AXX

[michael123]

Yes, I got the manual that came with it, however, a friend of mine said that the 704 would not work with my radio and now I am not sure what to do with it. I am going to have to try something else. Yes, I have the plug and play camble that came with the arb704.

Hi mtraxler,
how are you?
from where you got the manuals?
is it updated or new editions?

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