James ...
Additional information you will need and decisions you need to
make:
Question 1:? Do you intend to operate CW with your LA-1K?
If so, choose DIRECT keying mode in the LA-1K, but understand that
DIRECT keying mode requires that a band-data cable be inserted in
the DB9 jack.? Without this cable, the LA-1K reverts to NORMAL
keying which has the disadvantage of causing the first Morse
character to be truncated.? An
extended discussion of this issue can be found here:?
Likewise, the LA-1K manual says on page 21:
Question 2:? Do you intend to operate QSK (full break-in) with
your LA-1K?
Many CW operators do.? Unfortunately, the LA-1K is not
designed for QSK but can be made so by inserting an
external electronic T/R switch between the transceiver and the
amplifier.? There are several out there but the very best is the
DX Connections QSK-2500.? It is hand-made by K3HZP who offers
excellent technical support.? While the current price of $425 may
seem high, it is less than what Palstar would have to charge to
redesign the LA-1K.? It has the added advantage of being portable
and able to make any non-QSK amplifier a fully-QSK one.? I
have two of them, one for the LA-1K and one for vintage
equipment.? I use it nightly with a TS-890S on CW traffic nets at
speeds up to 30 wpm and is totally transparent.
The main DX Connections QSK-2500 website is here:?
Let me know if I can help further.
73,
Kent
K9ZTV
On 8/30/2024 10:54 PM, James wrote:
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At last, some useful assistance.? Many thanks.??
It is possible that the "band cable" that I have will perform
all of the needed tasks.? Need DB9 pin 7 to go to ground when
transmitting, and need to have the four "band" lines properly
connected.
What about the other four DB9 pins?
Before using the "DB 8MY2" cable I need to measure the
signals it provides and verify that it seems to work.? ?I expect
that using a resistor as a probe of the DB9 is a safe way to
measure with the other end connected to FT710.??
Sure wish we all had a good schematic and maintenance manual.
Have not received a response from
PALSTAR.? Several of their Email addresses no longer work.
Thanks Kent? ? Did you make your own cable
or an off-the-shelf cable?
James / Mac? ? N8TT
------ Original Message ------
Date 8/30/2024 5:34:00 PM
Subject Re: [la1k] FT710 to LA1K
James
...
FT-710 TUNER/LINEAR? ? ????????? LA-1K RADIO
INTERFACE (DB9)
RESET(BAND D).........................Pin 8
BAND C........................................Pin 9
TX D(BAND A).............................Pin 2
TX GND........................................Pin 7
RX D(Band B)...............................Pin 1
The LA-1K is keyed either by the transceiver's TX GND
connected to Pin 7 in the amp . . . or . . . TX GND in the
710 connected to the PTT RCA Phono jack on the back of the
LA-1K.? Either will work? fine, but not both.? One or the
other, but not both.? I use PIN 7 in the LA-1K's DB9 jack.
Secondly, by connecting the FT-710's band-data lines, the
amplifier follows the transceiver's band changes instantly.?
This has the advantage of having the amp's relays closed and
settled before any RF hits them.
Ignore TX INHIBIT.
73,
Kent
K9ZTV
On 8/29/2024 7:38 PM, James
wrote:
I was sold a "band cable" that is thought to connect to the
8 pin "Tuner/Linear" port on the F710 (upper left on the
back) and that it will supply band information to LA1K when
the other end is plunged into the back of LA1K.? This "band
cable" is Ameritron DB 8MY2.
Of course, the LA1K needs to know when the FT710
transmits.? ?The manual for the FT710 seems to indicate
that the 8 pins include a transmitter "ground" and a
"transmitter inhibit."? Does the LA1K use those two
signals to effect PTT?? (pulled low on transmit)
Details on how one has used FT710 with LA1K will be
most welcome.
73? ? James? ? N8TT
