Ft 991 and eco750

[ahasverus]

dear Knights of the Ham
i am ready to by the ft991 ( has also a 5w output) and eco750
but
1)will the high voltage of the eco750 not blow up the tx991 relay circuit
and can i use ex ARB704
2)the eco750 ( see http://www.wimo.com/amplifier-vhf-uhf_e.html) has a ptt so
RCA jack
I see yaesu 991 has a cable T9207451
ending wire: orange 13,8 v
yellow tx ground
green ground
and other colours (data etc)
is connecting green to outside rca and yellow to inside RCA
the right way (PTT)
i thank you for attention and will thank everyone who has helped me in the past
wish the family of the World Wide Radioforum beautiful days in 2016 days of health and joy

Ahasverus alias on3bm in QRZ.COM

 

[BJ radionut]

Info from PAGE 12 Operations manual:

Note  The TX GND OUT pin (pin 2) of the TUN/LIN jack is a transistor “open collector” circuit. It is capable of handling positive relay coil voltages up to +60VDC at 200 mA or +30 VDC at 1 A.
If you plan to use multiple linear amplifiers for different bands, you must provide external band switching of the “Linear Tx” relay control line from the “TX GND OUT” line at the TUN/LIN jack. 
The specified range for ALC voltage to be used with the FT-991 is 0 to -4 Volts DC.  Amplifier systems utilizing different ALC voltages will not work correctly with the FT-991, and their ALC lines must not be connected if this is the case. Important Note!  Do not exceed the maximum voltage or current ratings for the “TX GND OUT” pin (pin 2) of the TUN/ LIN jack.
This line is not compatible with negative DC voltages, or AC voltages of any magnitude.
 Most amplifier control relay systems require only low DC voltage/current switching capability (typically, +12V DC at 25 ~ 75 mA), and the switching transistor in the FT-991 will easily accommodate such amplifiers.

This should help answer your question...Not sure of the keying needed for your amp.
However noting in the info that this radio uses transistor switching...I think an external interface between amp and radio may be a good idea...Isolation for both switching circuits (amp and radio) would seem appropriate here IMHO.
Enjoy
Happy New Year 2016
All the Best
Gary/W9FNB

 

[n8fgb]

A modern solid state amplifier like that should take very little to key it. Check the manual when you get before you hook it up.
Rich

 

[n8fgb]

http://www.ssb.de/pdfs/Blueline-Bedienungsanleitungv4.pdf

My German is not very good, but I would have to say if you can program the keying delay, it is a solid state switch.

 

[fourstringburn]

I took a look at the amp you are interested in and I see nothing in the spec's that say if the keying voltage is positive or negative.

It is important you find out before you purchase both radio and amp.See if you can find a download link for the owners manual to get this info from.

As BJ Radionut stated,The Yaesu uses positive polarity for keying. If the amp uses positive voltage for keying you are in business. The Ameritron ARB-704 accepts both positive and negative voltages so there is no problem there and the ARB-704 makes a nice and easy plug and play connection along with buffering protection for keying with the radio brand specific accessory cable. I do recommend this as I use them on both my mobile and base stations.

ALC lines aren't always necessary, at least many of us don't think so. However, the ALC voltage on the Yaesu is negative polarity.

 

[ahasverus]

dear Knights of the Ham
i am ready to by the ft991 ( has also a 5w output) and eco750
but
1)will the high voltage of the eco750 not blow up the tx991 relay circuit
and can i use ex ARB704
2)the eco750 ( see http://www.wimo.com/amplifier-vhf-uhf_e.html) has a ptt so
RCA jack
I see yaesu 991 has a cable T9207451
ending wire: orange 13,8 v
yellow tx ground
green ground
and other colours (data etc)
is connecting green to outside rca and yellow to inside RCA
the right way (PTT)
i thank you for attention and will thank everyone who has helped me in the past
wish the family of the World Wide Radioforum beautiful days in 2016 days of health and joy

Ahasverus alias on3bm in QRZ.COM

 

[ahasverus]

dear friends
thank you for advice
need some more time to see the light
the eco has + and -
using the arb 704 seems impossible as the eco has only a rca ptt no relay/ no alc so
have to dig a bit more
greetings

 

[fourstringburn]

If the Eco has selectable PTT polarity voltage, then it seems to me you are good to go.

This amp appears to have user adjustable PTT delay which is a relay control.
It would be easier for us "Yanks" if their owners manual was in English since in Duetch it says this;

Einstellung des PTT Delays, also der Zeit die zwischen dem Drücken des PTT Tasters und
dem Start der Sendung vergeht. Relaisbedingt ist 30ms das Minimum.

Which translates to this:

Setting of the PTT delay, i.e. is the time elapsed between pressing the PTT button and the start of the broadcast. Due to the relay, 30ms is the minimum.

The reason why I said many of us don't think using ALC on amplifiers is necessary is because you can regulate ALC by judicious monitoring of the radio's ALC meter by properly setting the mic gain and compression settings if used. I have seen other amps with no ALC connection so I wouldn't be too concerned about it.

You can still use the ARB-704 with the Yaesu 8 pin cable ( should be the Ameritron PNP-8M ) as this not only gives you over voltage relay protection but makes nice and neat cable connections to the amp without wiring up an accessory jack plug to phono jack cable.

Bon chance, 73

 

[Heavy Metal]

Now explain the proper way on radio to set and monitor both ALC and Comprssion if your not going to use and ARB-704 box, Just curious

 

[fourstringburn]

Now explain the proper way on radio to set and monitor both ALC and Comprssion if your not going to use and ARB-704 box, Just curious

Easy, adjust mic gain so your normal spoken voice falls within but not over the scale of your ALC meter on your radio. This should allow headroom for allow for peaks.

If compression is used, do the same thing but you need to adjust the compression output level along with the mic gain together and cut one back or the other or both to keep the ALC level in check.

I keep my compression level peaking around 6 DBs and it usually works with my mic gain setting to keep the ALC at about 70% of the scale. I personally don't like the sound when people use heavy compression settings.

 

[Heavy Metal]

Wow excellent explanation.

Mine doesn't have a scale just a line and compression numbers 10 ----- 20 ect suppose to keep it on compression between 10-20 no one has said I am over modulating and I use either a stock mic or a D-104 and run it v v v low on gain setting on bottom of it.