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K1-4 Low power output only on 15 meters.

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Jimithy66

K1-4 Low power output only on 15 meters.

My K1 was a wonderful radio on all bands 40 - 17m.

However 17m saw very little use and 15m was desired..

The 26.050 crystal was replaced with the kit supplied 29.000 MHz
crystal for 15m and the K1 realigned on all bands.

All seemed to go well with the receive and transmit alignment
with the power level set to 2 watts per the manual.

However now the power will not go above 2 watts on 15m..

All bands go to 5 watts measured on a WM-2 watt meter
but on 15m the output stops at 2 watts..

15m programs OK from 0.2 to 2.0 watts output but not higher.

The K1 display reads 5.0 when being set with buttons but
the K1 power output display reads only around 2.1 or so watts.
.
All frequencies are correct on another receiver.

Am I missing something ? Any help would be appreciated.

Thank you , 72/73

Jim / W1FMR

.
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Mike Morrow-3

Re: K1-4 Low power output only on 15 meters.

Jim / W1FMR wrote:

> The 26.050 crystal was replaced with the kit supplied 29.000 MHz
> crystal for 15m and the K1 realigned on all bands.
>
> All seemed to go well with the receive and transmit alignment
> with the power level set to 2 watts per the manual.
>
> However now the power will not go above 2 watts on 15m..

Jim, were you *ever* able to maximize 15m power during transmitter
alignment (KFL1-4 manual page 19) *above* 2 watts? During alignment
the power must be peaked, likely several times, well above 2 watts.

The alignment procedure has you select the desired power level during
alignment to 2 watts to set the maximum power that will exist *only at
the start* of the capacitor adjustments for that band. After a couple
of seconds of being in TUNE, ALC is no longer altered by the MPU as
power output changes. The power level should go well above 2 watts
as you peak the capacitor settings, possibly to the point where other
physical effects are limiting the output power. That would make it
difficult to accurately peak the filter board adjustments. In that
event the manual has you exit TUNE, then re-enter TUNE. That resets
the ALC to lower the max power to 2 watts. A couple of seconds later
the ALC will remain constant, even as the power again rises well above
2 watts as you resume peaking the filter board capacitors. Repeat as
necessary.

I'm pretty sure that you are well aware of all that. But it almost
sounds like the peaking adjustment for 15m was halted the first
time the 2 watts level was reached. If that happened, you will need
to go back and re-perform the transmitter alignment on KFL1-4 manual
page 19 for 15m, followed by 20m. It would likely be worthwhile to
do that anyway, since it's such an easy process.

> The K1 display reads 5.0 when being set with buttons but
> the K1 power output display reads only around 2.1 or so
> watts.

For which the simplest explanation is that the capacitors for 15m
never got peaked to produce any higher power level. The ALC wants
to set 15m power to 5 watts, but the (mis)alignment is not permitting
levels above 2.1 watts to be reached.

That's my best guess.

73,
Mike / KK5F

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"Hjalmar Duklæt"

Re: K1-4 Low power output only on 15 meters.

In reply to this post by Jimithy66

Hi Jim.
I've had the same problem with my K1. It turned out to be a bad crystal, so my suggestion is to get another crystal for the 15m band.
73 de Hal
la4xx

On 13-06-12, Jimithy66 <[hidden email]> wrote:

> My K1 was a wonderful radio on all bands 40 - 17m.
>
> However 17m saw very little use and 15m was desired..
>
> The 26.050 crystal was replaced with the kit supplied 29.000 MHz
> crystal for 15m and the K1 realigned on all bands.
>
> All seemed to go well with the receive and transmit alignment
> with the power level set to 2 watts per the manual.
>
> However now the power will not go above 2 watts on 15m..
>
> All bands go to 5 watts measured on a WM-2 watt meter
> but on 15m the output stops at 2 watts..
>
> 15m programs OK from 0.2 to 2.0 watts output but not higher.
>
> The K1 display reads 5.0 when being set with buttons but
> the K1 power output display reads only around 2.1 or so watts.
> .
> All frequencies are correct on another receiver.
>
> Am I missing something ? Any help would be appreciated.
>
> Thank you , 72/73
>
> Jim / W1FMR
>
>
>
>
>
>
>
> .
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email] <[hidden email]>
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>
>

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Don Wilhelm-4

Re: K1-4 Low power output only on 15 meters.

In reply to this post by Jimithy66

Jim,

Either you have a weak 15 meter crystal, or the bandpass filters are not
properly peaked on 15 meters.
Do you have an RF Probe or a 'scope? If so, measure the RF voltage at
P1 pin 6 on the 4 band board. It should be greater than 70 mV rms or
200 mV peak to peak. You can do a preliminary peaking of the pre-mixer
bandpass in receive while monitoring the RF voltage at this point.

Be certain you are tuning to 15 meters instead of at a higher frequency
- do the initial peaking during receive while listening to a known 15
meter signal. If you do not have a signal generator, use another
transmitter operating into a dummy load and place the end of a 'hunk of
wire' antenna close to the dummy load.

On the suspicion that there is some other problem in the RF transmit
chain limiting the output to 2 watts, do the transmit peaking at 1 watt
instead of 2 watts. If the power goes up to 2 watts during the process,
exit TUNE and reenter to bring the power back down to 1 watt and
continue to try to find the peak.

73,
Don W3FPR

On 6/11/2013 11:58 PM, Jimithy66 wrote:

> My K1 was a wonderful radio on all bands 40 - 17m.
>
> However 17m saw very little use and 15m was desired..
>
> The 26.050 crystal was replaced with the kit supplied 29.000 MHz
> crystal for 15m and the K1 realigned on all bands.
>
> All seemed to go well with the receive and transmit alignment
> with the power level set to 2 watts per the manual.
>
> However now the power will not go above 2 watts on 15m..
>
> All bands go to 5 watts measured on a WM-2 watt meter
> but on 15m the output stops at 2 watts..
>
> 15m programs OK from 0.2 to 2.0 watts output but not higher.
>
> The K1 display reads 5.0 when being set with buttons but
> the K1 power output display reads only around 2.1 or so watts.
> .
> All frequencies are correct on another receiver.
>
> Am I missing something ? Any help would be appreciated.
>
> Thank you , 72/73
>
> Jim / W1FMR
>
>
>
>
>
>
>
> .
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>