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K2 with rigblaster

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djl

K2 with rigblaster

I'm trying to use a Rigblaster plus with my K2 with 100 watt amp and tuner.
I've also tried a MFJ TNC switch. Both for digital mode and microphone
switching. When I use these devices I get interference when in mic mode from
rf pickup. With the mic alone., no problem. Has anyone out there had this
problem? I've tried ferrite chokes on all lines, routing the cables in
different places, etc.etc. I'm totally stumped and very disappointed that I
have to manually replug everything to accomplish a simple (?) switching task.
Anyone out there faced this problem? Any advice?
Thanks
Don

--
"Noli sinere nothos te opprimere"

Dr. Don Latham AJ7LL
Six Mile Systems LLC
17850 Six Mile Road
Huson, MT, 59846

mail: POBox 404
Frenchtown MT 59834-0404

VOX 406-626-4304
CEL 406-241-5093
Skype: buffler2
www.lightningforensics.com
www.sixmilesystems.com

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Don Wilhelm-4

Re: K2 with rigblaster

Don,

First get some copper braid or #10/12 stranded wire and bond things
together. bond from the computer to the Rigblaster, the Rigblaster to
the K2, the K2 to the KAT100, and from there, bond the KAT100 to the
station ground.
Secondly, make certain all your station equipment is powered from the
same electrical receptacle (everything connected to the same 'green wire
ground'.

What I am relating in simplified format is the same as you can find in
K9YC's writings - see http://k9yc.com/GroundingAndAudio.pdf for a LOT
more information on the subject, including the "why" of it all.
If you currently have all your station boxes connected to a bus bar
behind the desk or to a single point station ground, look at what Jim is
telling us in that presentation and try his grounding method instead -
it is designed to reduce hum and noise in your audio circuits. Using
heavy wire or braid for the bonding assures that you still have good
lightning protection in the shack.

If you have station ground rods driven that are not connected with heavy
wire (#4 or #6) to the utility entrance ground, add that connection, not
only for possible noise reduction, but also for your personal safety as
well as compliance with National Electrical Code requirements.

73,
Don W3FPR

On 6/15/2015 4:33 PM, Don Latham wrote:

> I'm trying to use a Rigblaster plus with my K2 with 100 watt amp and tuner.
> I've also tried a MFJ TNC switch. Both for digital mode and microphone
> switching. When I use these devices I get interference when in mic mode from
> rf pickup. With the mic alone., no problem. Has anyone out there had this
> problem? I've tried ferrite chokes on all lines, routing the cables in
> different places, etc.etc. I'm totally stumped and very disappointed that I
> have to manually replug everything to accomplish a simple (?) switching task.
> Anyone out there faced this problem? Any advice?
> Thanks
> Don
>
>

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Pete Smith N4ZR

Re: K2 with rigblaster

In reply to this post by djl

What mix ferrites are you using, Don? How many turns? Is there any
difference in the intensity of the problem when you change bands?

73, Pete N4ZR
Download the new N1MM Logger+ at
<http://N1MM.hamdocs.com>. Check
out the Reverse Beacon Network at
<http://reversebeacon.net>, now
spotting RTTY activity worldwide.
For spots, please use your favorite
"retail" DX cluster.

On 6/15/2015 4:33 PM, Don Latham wrote:

Vic Rosenthal

Re: K2 with rigblaster

In reply to this post by djl

K9YC's grounding and choking methods are one part of the solution. The other is reducing the amount of RF flowing on your station equipment. Off-center fed antennas and verticals often produce common-mode currents on feed lines. Changing the feed line length away from odd multiples of 1/4 wavelength helps, although you can make the situation worse on one band while improving it on another. Antennas should have chokes or baluns at the feed points, and it may help to also have a choke where the coax comes into the shack. Take care not to ground the feed line on the antenna side of the choke, because this 'shorts' it, rendering it ineffective.

Vic 4X6GP/K2VCO

> On Jun 15, 2015, at 11:33 PM, Don Latham <[hidden email]> wrote:
>
> I'm trying to use a Rigblaster plus with my K2 with 100 watt amp and tuner.
> I've also tried a MFJ TNC switch. Both for digital mode and microphone
> switching. When I use these devices I get interference when in mic mode from
> rf pickup. With the mic alone., no problem. Has anyone out there had this
> problem? I've tried ferrite chokes on all lines, routing the cables in
> different places, etc.etc. I'm totally stumped and very disappointed that I
> have to manually replug everything to accomplish a simple (?) switching task.
> Anyone out there faced this problem? Any advice?
> Thanks
> Don
>
>
> --
> "Noli sinere nothos te opprimere"
>
> Dr. Don Latham AJ7LL
> Six Mile Systems LLC
> 17850 Six Mile Road
> Huson, MT, 59846
>
> mail: POBox 404
> Frenchtown MT 59834-0404
>
> VOX 406-626-4304
> CEL 406-241-5093
> Skype: buffler2
> www.lightningforensics.com
> www.sixmilesystems.com
>
>
> ______________________________________________________________
> 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
> Message delivered to [hidden email]

Jim Brown-10

Re: K2 with rigblaster

In reply to this post by Don Wilhelm-4

> I've also tried a MFJ TNC switch. Both for digital mode and microphone
> switching. When I use these devices I get interference when in mic
> mode from
> rf pickup. With the mic alone., no problem.

In addition to Don's advice, I'll add this. Most electronic boxes have
Pin One Problems, and that very likely includes all that you're trying
to interconnect. I suggest dumping the TNC switch and instead make a
cable that goes from your Rigblaster to the K2 mic input, with shields
connected to the CHASSIS of the K2. Build a simple 10:1 (-20dB) voltage
divider as described in the link that Don gave you. It's often possible
to put that inside the connectors -- it's a series R and a parallel R. I
often put the series R in the connector for the driving box, and the
parallel R in the mic connector.

If the bonding described in the link doesn't solve your problems, add a
multi-turn ferrite choke to both of the cables between the K2 and the
computer, and also to the cable connecting the Rigblaster to the
computer. 5 turns through a typical #31 or #43 clamp-on is about right
for 40M - 10M.

We have these problems because the guys who design ham gear and consumer
gear and computer gear know nothing about RFI, and they ignore the
advice of the audio engineers who discovered "The Pin One Problem" more
than 20 years ago. The logic appears to be "audio is only 20-20,000 Hz,
those guys can't possibly know as much about EE as we do -- our stuff
goes to GHz!"

FWIW, I have no use for the dedicated ham interface boxes no matter
whose name is on them -- the wiring interface for the ones I've seen are
an invitation to RFI and hum/buzz problems, and most have Pin One
Problems. A very good USB sound card can be bought for $70 (see the ASUS
U5 Zonar), You can build a WinKey for about $75, or the Yankee Clipper
SO2R box for about twice that cost. A serial to serial cable is two
connectors and some CAT5. Serial to USB adapters are inexpensive.

There are several tutorials on The Pin One Problem on my website.

73, Jim K9YC
Vice-Chair AES Standards Committee Working Group on EMC
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Joe Subich, W4TV-4

Re: K2 with rigblaster

On 2015-06-16 1:29 AM, Jim Brown wrote:
> FWIW, I have no use for the dedicated ham interface boxes no matter
> whose name is on them -- the wiring interface for the ones I've seen
> are an invitation to RFI and hum/buzz problems, and most have Pin
> One Problems. A very good USB sound card can be bought for $70 (see
> the ASUS U5 Zonar), You can build a WinKey for about $75, or the
> Yankee Clipper SO2R box for about twice that cost. A serial to serial
> cable is two connectors and some CAT5. Serial to USB adapters are
> inexpensive.

That's all well and good for someone with your experience and retired
with time on his hands. However, when one counts the cost of all the
individual *kit* pieces - $300 to $400 - add USB to serial converters
(even though inexpensive they add up), a proper FSK interface like the
K0SM or K8UT devices, includes the time to build/integrate everything,
and then troubleshoot the interactions, the cost of dedicated ham
interface boxes is very reasonable for a single box, plug and play
solution.

The pin 1 problems go back to the transceiver - there isn't a single
amateur transceiver (that I know of) that properly bonds *all* signal
returns to the chassis. Most of them don't even have a metal chassis
any more and many of those that do use non-conductive enamel or power
coating that prevents proper bonding in the first place. Everything
is mounted on circuit boards with several inches of traces before the
return signal actually reaches the chassis (if it ever does).

Once the transceiver builds in a pin 1 problem, there is very little
that an interface - yours included - can do to solve the issue. One
can only use balanced connections, twisted pair cables, isolation
transformers and bonding to minimize the problems. Add the tremendous
lack of understanding about common mode RF (RF on the outside of the
feedline) and complete ignorance issues of high current returns (TX
current returning to a common power supply via accessories) and it's
a wonder that most amateur stations don't have wore problems than they
do.

73,

... Joe, W4TV

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