[600MRG] Relay failure on FT891 at w0yse

[Tom W8JI]

This is not a sequencing issue.

There is a menu item that, if off, with disable the TX GND line used for 
tuners and linear amplifiers. It has to be on "Lamp" in the settings menus.

It is menu 16-15 "Tuner Select" and has four settings.

This has to be selected when an external device is controlled from the 
DIN plug. Neil needs an appropriate interface or he can damage the 
radio.  I believe the FT891 is a transistor output for TX GND but it has 
been a few years since I looked at one.

Anyway, Neil should check the menu first because the TX send is a menu 
selected pin on the DIN plug. I know this because a friend could not get 
his to work and he had that menu item off.

73 Tom


On 10/20/2023 12:02 AM, Ed Cole wrote:
> Neil,
>
> Not exactly clear what you are referring to FT891 "grounding pin"?  I 
> suspect this to be a way to key external devices when your FT891 goes 
> into transmit mode.
>
> On my K3 that output is called KEY OUT.
>
> We encounter issues getting components into Tx state when doing eme. 
> universally a sequencer is used that stages the transfer to Tx of 
> several components in sequence in order to not transmit RF in the 
> wrong direction.
>
> I use a four-stage sequencer that:
> 1. turns off dc power to my preamp
> 2. switches TR relay to Tx state
> 3. Enables amplifiers to Tx
> 4. Keys transmit radio into Tx
>
> Each is separated by several msec delay.
>
> My sequencer is made by Down East Microwave (model TRS).
>
> The sequencer can either by controlled by an external switch or by a 
> computer: RS-232 DTR or RTS line or via USB/RS232 conversion cable.
>
> When station power is off the system defaults into transmit 
> configuration to protect everything.
>
> Others, such as W6PQL, offer sequencers.
>
> 73, Ed - KL7UW
>
> My 630m station made first step toward operation with the raising of a 
> 80m folded dipole to 36-feet AGL, fed with open ladder wire. 
> Eventually the feed wire will be shorted to drive with a large base 
> loading coil to become a top-loaded a "T" vertical.  Too late to lay 
> ground radials this year as temps are going below 32F in daytime (and 
> snow not far off).
>
> Ground radials will be placed on the ground held by wire staples 
> (obtained from DX Engineering).  This will hold wire below mower blade 
> level.  Green insulated No. 12 THHN is being used.
>
> On 10/19/2023 2:33 PM, Neil Klagge wrote:
>> Well, a new wrinkle in my quest to make a QSO on 630m this 
>> fall/winter.    My T/R relay wont work because the TX-grounding pin 
>> in my FT891 quit working. Probably bad contacts on the internal relay 
>> in my radio.
>>
>> Now the only way I can switch between my RX active loop and my MF TX 
>> antenna is by a manual switch. That will eventually be a problem the 
>> first time I accidentally put some RF into the active amplifier at 
>> the RX loop.
>>
>> I am about ready to give up on 630m after this major setback. At this 
>> point I can either RX or TX but not both without possible damage to 
>> the loop.
>>
>> I have looked at some of the MFJ RF switches but none of them seem to 
>> be right for my situation.
>>
>> Hoping to get some inspiration from above....
>>
>> 73
>>
>>>> **´¨)
>>>> ¸.•´¸.•*´¨) ¸.•*¨)
>>>> *
>>>> *(¸.•´ (¸.•`   Neil *, wØyse, DN41ah, North Ogden, Utah 84414
>>> BCC: Gene & Stan
>>
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