[sarcmembers] Re: Sequencing the FT-736

  • From: george bernard <gbernard@xxxxxxxxx>
  • To: john maetta <sarcmembers@xxxxxxxxxxxxx>
  • Date: Fri, 22 May 2009 06:54:29 -0700

john,  i have been using cw on 2 m and also 432  on the ft-736 recently.   i 
call cq ssb which means if you hear me come back to me on ssb.

we have been doing this for many years.  also,  who locked the door into the 
shop?  i was going to put handles on the grey cabinets last night

after the 432.12 net?   the sign on the door says "dont lock this door" .  
regars, george bernard  w6nre


ps:  can anybody  ID this radio?  hint:  either magnavox or collins
santa barbara, ca web page is www.balanceindustries.com for my company cell 
818-370-9407


 


From: j.maetta@xxxxxxxxxxx
To: sarcmembers@xxxxxxxxxxxxx
Subject: [sarcmembers] Sequencing the FT-736
Date: Thu, 21 May 2009 17:25:21 -0700


Dave,
 
Explaining my findings will be difficult via email, but I'll try.
 
The FT-736 presents some obstacles to making the sequencing foolproof.
 
To make any system foolproof we should sequence the system in the following 
order:
 
Pressing the mic PTT starts the sequencer events.
Event #1 - Bypass the preamp
Event #2 - Key amplifier
Event #3 - 
Event #4 - Key transceiver to apply RF. (Most new rigs have an a port that can 
be used to hold off all RF until an external signal is applied. Unfortunately, 
the FT-736 doesn't have this valuable circuitry)
 
I asked the Moon-Net forum for any suggestions on sequencing the FT-736 and got 
many replies and solutions. Most are simple and only require a modification to 
the mic to place its PTT in series with the sequence's Event #4, allowing Event 
#4 to be routed to the rig's mic input. These solution will not allow CW 
operation.
 
Others were footswitches and external PTT buttons mounted on the desktop and 
these allowed CW to be used.
 
The real problem, and this is where is becomes non-foolproof, is the MOX 
(Manually Operated Transmit) button on the front panel of the FT-736. It will 
not start a sequence and will immediately apply RF to the system and burn the 
preamp out. I have seen this button used in normal operation and it has made me 
kringe. 
 
Moon-Net, provided some solutions to that issue. The solutions ranged from 
disabling the MOX button to the modification of internal circuitry to hold of 
RF until Event #4 enabled it. Both of these were not diffcult, but in our case 
require some approval. 
 
Another solution is to educate users to not use the MOX button or CW. We have 
the potential for many users of the system, some may be unaware of the 
limitations.
 
I could use any help you guys can provide.
 
My TS-790 sequencing is not foolproof, but I put it together and know its 
limitations and have so far avoided catastrophy. 
 
73
 
John
 
----- Original Message ----- 

From: David Dowler 
To: sarcmembers@xxxxxxxxxxxxx 
Sent: Thursday, May 21, 2009 6:39 AM
Subject: [sarcmembers] Re: Help!...Need 220Mhz yagi for ARRL June 12-13 VHF 
Contest

John

What do you need for the 736 interface. I may be able to help out.

Dave  KA6BFB

John Maetta wrote: 



Hi George,
 
Since my time before the contest is short, I have set my own agenda for 
Saturday. When I get done and if there is time, I would be glad to help 
wherever I can.
 
Here are the tasks I have to get ready for the contest:
 
Repair broken element on 50Mhz yagi.
Assemble 220Mhz yagi.
Build and run feed lines for 50Mhz yagi and 220Mhz yagi.
Assemble Cushcraft 13B2.
Test portable tower rotator.
 
I have the sequencer built, but I am struggling with how to interface it to the 
736. The 736 offers some challenges to properly, safely and foolproof the 
switching.
 
John
 

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