Need some help on a K1 problem.

[Len [K4IWL]]

I'm hoping that there are still some K1 aficionados out there.
 
 
I ordered my K1 with the 4-band-filter board. I was not able to get the
4-band-filter to work so I ordered the 2-band-filter (since it's a simpler
board) so I could determine if it's a problem with the K1 main board or the
filter board. To make a long story short, the K1 with the 2-band-filter
works perfectly (40/20M) and the relay switching works. I then finished the
KAT and it works with the 2BFB just fine.
 
But here's the problem, I am still debugging the 4-band-filter inbetween
using the K1 with the 2BFB. When I plug in the 4BFB there is no relay
activity at all when I switch bands. The relays stay in the reset position.
I have run out of ideas. Here is what I've done:
Replaced the 4MHz resonator. Replaced the IOC with a spare that I have. So
far nothing works. I have visually inspected every solder joint. I have
reflowed the solder on all the IOC and resonator pads. I have checked
continuity between the IOC pins and the relays and they are all solid. I
have checked the common connection to all the relays for shorts and opens. I
have checked continuity through RFC1. There are no shorts that I have
detected or seen on the board (solder splashes, globs, etc.) although I'm
not ruling that out yet. Nothing I've done fixes it.
 
Any new ideas out there? Anybody else have this same or similar problem? The
relay switching has nothing to do with the RF paths, these appear OK when I
manually apply 1.5V to selected relays for the band configuration. RF is
getting through as it should on each of the 4 bands. Oh .. yeh ... I am not
getting any error codes on the display either. And when I switch the bands
with the front panel switch, the display changes but no relays activate.
 
72,
LEN, K4IWL
www.qrz.com/k4iwl
K2 #848,  K1 #1221,  Wilderness Radio Sierra (another Wayne rig),
Every RockMite imaginable, and a 15M HiMite.

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[Don Wilhelm-4]

Len,

Are you certain it is a relay problem?
Does your 4 band board work on 15/17 meters without manually setting any
relays?
If it is a relay problem, the reset state of the relays is with the 15
meter band selected and you should be able to align and operate it on
that band.

Can you turn the attenuator on and off with this 4 band board
installed?  If so, the IOC chip is working and the resonator is good.

If you do have a relay problem, make continuity checks from the U1 pins
to pin 8 of each relay (check the schematic to determine the
corresponding pins of U1), and check continuity from P2 pin 3 to each of
the relays Pin 1.  When checking to the U1 pins, plug the firmware chip
in and measure from the actual lead of the chip rather than the socket -
that will reveal any socket problems.

Check the resistance of each relay coil to see if you might have one
with an open coil.

Too much solder can mask a bad solder connection.  If your solder
fillets have a convex shape to them, you have too much solder applied -
wick the excess away.  A good solder joint will have a small fillet with
a concave appearance where the solder flows out to a nearly invisible
edge on both the solder pad and the component lead.  You may not believe
how many problems I have fixed simply by removing the excess solder and
reflowing solder in the process.  At least 40% of the problems builders
have are soldering related and at least 40% are toroid lead problems,
another 18% are incorrect component placement while the remaining 2% can
be attributed to bad parts (usually damaged by the builder).

73,
Don W3FPR

Len [K4IWL] wrote:

> I'm hoping that there are still some K1 aficionados out there.
>  
>  
> I ordered my K1 with the 4-band-filter board. I was not able to get the
> 4-band-filter to work so I ordered the 2-band-filter (since it's a simpler
> board) so I could determine if it's a problem with the K1 main board or the
> filter board. To make a long story short, the K1 with the 2-band-filter
> works perfectly (40/20M) and the relay switching works. I then finished the
> KAT and it works with the 2BFB just fine.
>  
> But here's the problem, I am still debugging the 4-band-filter inbetween
> using the K1 with the 2BFB. When I plug in the 4BFB there is no relay
> activity at all when I switch bands. The relays stay in the reset position.
> I have run out of ideas. Here is what I've done:
> Replaced the 4MHz resonator. Replaced the IOC with a spare that I have. So
> far nothing works. I have visually inspected every solder joint. I have
> reflowed the solder on all the IOC and resonator pads. I have checked
> continuity between the IOC pins and the relays and they are all solid. I
> have checked the common connection to all the relays for shorts and opens. I
> have checked continuity through RFC1. There are no shorts that I have
> detected or seen on the board (solder splashes, globs, etc.) although I'm
> not ruling that out yet. Nothing I've done fixes it.
>  
> Any new ideas out there? Anybody else have this same or similar problem? The
> relay switching has nothing to do with the RF paths, these appear OK when I
> manually apply 1.5V to selected relays for the band configuration. RF is
> getting through as it should on each of the 4 bands. Oh .. yeh ... I am not
> getting any error codes on the display either. And when I switch the bands
> with the front panel switch, the display changes but no relays activate.
>  
> 72,
> LEN, K4IWL
> www.qrz.com/k4iwl
> K2 #848,  K1 #1221,  Wilderness Radio Sierra (another Wayne rig),
> Every RockMite imaginable, and a 15M HiMite.
>
> _______________________________________________
> Elecraft mailing list
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> You must be a subscriber to post to the list.
> Subscriber Info (Addr. Change, sub, unsub etc.):
>  http://mailman.qth.net/mailman/listinfo/elecraft   
>
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> Elecraft web page: http://www.elecraft.com
>
>
>  

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[Andrew Moore-3]

> Any new ideas out there? Anybody else have this same or similar problem?

Don't overlook the possibility that a socketed microprocessor chip got
one of its legs splayed out and isn't actually in the socket.
Scrutinizing solder joints won't help in that scenario, and it's easy
to overlook.  It happened to me once or twice before.

--Andrew
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