[1000mp] MkV Amp interfacing questions

Wed, 6 Nov 2002 07:55:43 -0000

Based upon the post, below, I checked the value of menu item 7-4 on my MP,
and found it to be 30 ms---the maximum value---rather than the factory
default of 5 ms. I then varied it across its range of 0 to 30 ms and found
that any value below 20 ms appeared to be extremely clicky, listening to
either sidetone or monitor, with or without keying the Alpha 87A.
Subjectively, I left it at 30.

I have not seen much discussion on this reflector about that memory item.

Please send comments on this subject to me directly: [email protected]. As I am
leaving the country in a few days, I have bailed out of all reflector lists
tonight, and will not receive any more list emails until Thanksgiving.

Garry, NI6T.

> -----Original Message-----
> From: [email protected]
> [mailto:[email protected]]On Behalf Of lhlousek
> Sent: Tuesday, November 05, 2002 15:17
> To: 1000mp list
> Subject: Re: [1000mp] MkV Amp interfacing questions
>
>
> Hi Earl,
>
> I started this thread with respect to hooking up an Ameritron
> AL-800H amp with the internal QSK-5 PIN diode T/R
> switching option.  Rather than using the amp keying relay in the
> MkV, pin 2 of the Band Data jack is used to key the
> amp.  The QSK-5 requires that the TX "relay" line go low at least
> 1msec prior to RF being present at it's input.  With
> the MkV, the required 1 msec delay can be set in menu item 7-4.
> This setting does not simply clip the first dot or dash
> but delays the entire CW string.
>
> The QSK-5 also has a TX open collector inhibit line that pulls
> low when the QSK switch is ready for RF after it gets
> keyed by the "relay" line.  This can be used as a safety to
> prevent the exciter from transmitting before the QSK-5 has
> switched to TX mode.  The inhibit line is connected to the MkV's
> TX inhibit input which is pin 8 of the Band Data jack.
> However, this will have no effect unless pin 8 is first pulled
> high inhibiting TX.
>
> To pull the inhibit line high I put a ~2K pull-up resistor
> between pins 1 and 8 of the band data jack but this had the
> unintended effect of disabling MkV TX when the amp was powered
> down.  I have since removed that resistor and added the
> pull-up resistor on the QSK-5 board so when the amp is off, there
> is no inhibiting voltage on pin 8.  Now the MkV well
> transmit with the amp off, with the amp on and in standby, and is
> inhibited from transmitting when the amp is in line
> unless the QSK-5 switch is ready.
>
> Anyway, the end result is that QSK wise, you can't tell the amp
> is in line.
>
> BTW, with this amp you should most definitely use the ALC line.
> It greatly simplifies tuning by preventing the amp from
> tripping off line due to high grid current.  Of course by doing
> this, it might also prolong the life of the tubes. It
> can be set high enough so as not to clip or cause distortion
> (which according to Ameritron, it doesn't do anyway due to
> it's progressive nature) when the amp is properly tuned,.
>
> Lou W7dzn
>
>
>
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