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P3 Hash

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Gene Trasti

P3 Hash

> P3 with svga
>
> I have a considerable amount of "hash" on my panadapter screen. It tracks the same spot on all bands. All my equipment is very well grounded. I have measured my shack for RFI-it is very clean. I swapped out my switching power supply for a highly filtered one. I even purchased a pretty expensive ac terminal strip with isolation transformers. I have been through the house and have virtually switched off and unplugged everything-nothing seems to help. This hash takes up a pretty healthy portion of the bandwidth. Any sugestions would be appreciated. Is it possible that this could be a problem with the P3 or K3 they are both factory built-although I added the svga board using a wrist ground..
>
>
> Gene. W6jmp
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rowland

Re: P3 Hash

I had the same problem. Replacing the BNC coax cable (between the P3 and
K3) with one I had lying around fixed it. Howard at Elecraft tech
support then sent a new cable that arrived 36 hours after I talked to
him. This new cable from Elecraft worked fine, for a while, but then
started having the same kinds of problems. I put my old cable that I had
lying around back on and it's worked for several months now.

I haven't pursued getting a second replacement from Elecraft because it
hardly seems worthwhile. In addition, it's not 100% clear to me that the
problem is the cable. With the 2 Elecraft cables I've noticed some
difficulty in connecting the BNC plug to the BNC receptacle on the back
of the P3. Not so with my old cable. The supposition being that the
physical dimensions of BNC receptacle on the P3 aren't quite right.
Whereas the new cables have a problem fitting, my old cable may be worn
enough that it fits anyway.

On 8/17/2012 9:00 AM, Gene Trasti wrote:

>> P3 with svga
>>
>> I have a considerable amount of "hash" on my panadapter screen. It tracks the same spot on all bands. All my equipment is very well grounded. I have measured my shack for RFI-it is very clean. I swapped out my switching power supply for a highly filtered one. I even purchased a pretty expensive ac terminal strip with isolation transformers. I have been through the house and have virtually switched off and unplugged everything-nothing seems to help. This hash takes up a pretty healthy portion of the bandwidth. Any sugestions would be appreciated. Is it possible that this could be a problem with the P3 or K3 they are both factory built-although I added the svga board using a wrist ground..
>>
>>
>> Gene. W6jmp
> ______________________________________________________________
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>

--
Rowland R Johnson
[hidden email]

www.lascanadas.org
House 805-438-3673
Cell 805-305-5252
Fax 805-438-4970

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Jack Smith-6

Re: P3 Hash

Some Chinese BNC male connectors don't properly mate with a
dimensionally correct BNC female.

Not sure where the dimensional problem is, but I've run into the problem
more than once.

Jack K8ZOA

On 8/17/2012 1:15 PM, Rowland R Johnson wrote:

> I had the same problem. Replacing the BNC coax cable (between the P3 and
> K3) with one I had lying around fixed it. Howard at Elecraft tech
> support then sent a new cable that arrived 36 hours after I talked to
> him. This new cable from Elecraft worked fine, for a while, but then
> started having the same kinds of problems. I put my old cable that I had
> lying around back on and it's worked for several months now.
>
> I haven't pursued getting a second replacement from Elecraft because it
> hardly seems worthwhile. In addition, it's not 100% clear to me that the
> problem is the cable. With the 2 Elecraft cables I've noticed some
> difficulty in connecting the BNC plug to the BNC receptacle on the back
> of the P3. Not so with my old cable. The supposition being that the
> physical dimensions of BNC receptacle on the P3 aren't quite right.
> Whereas the new cables have a problem fitting, my old cable may be worn
> enough that it fits anyway.
>
>
> On 8/17/2012 9:00 AM, Gene Trasti wrote:
>>> P3 with svga
>>>
>>> I have a considerable amount of "hash" on my panadapter screen. It tracks the same spot on all bands. All my equipment is very well grounded. I have measured my shack for RFI-it is very clean. I swapped out my switching power supply for a highly filtered one. I even purchased a pretty expensive ac terminal strip with isolation transformers. I have been through the house and have virtually switched off and unplugged everything-nothing seems to help. This hash takes up a pretty healthy portion of the bandwidth. Any sugestions would be appreciated. Is it possible that this could be a problem with the P3 or K3 they are both factory built-although I added the svga board using a wrist ground..
>>>
>>>
>>> Gene. W6jmp
>> ______________________________________________________________
>> Elecraft mailing list
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>>
>>

rowland

Re: P3 Hash

I took a close look and the BNC on the P3 and the center conductor
either was faulty to begin with or was damaged by the male BNC being
misaligned. My old cable still fits without any difficulty. I'm
supposing that, although it's not certain, it's likely that this caused
the hash seen on the P3.

Anyway, Howard at Elecraft is sending a replacement board that has the
damaged BNC receptacle.

On 8/17/2012 11:02 AM, Jack Smith wrote:

> Some Chinese BNC male connectors don't properly mate with a
> dimensionally correct BNC female.
>
> Not sure where the dimensional problem is, but I've run into the problem
> more than once.
>
> Jack K8ZOA
>
> On 8/17/2012 1:15 PM, Rowland R Johnson wrote:
>> I had the same problem. Replacing the BNC coax cable (between the P3 and
>> K3) with one I had lying around fixed it. Howard at Elecraft tech
>> support then sent a new cable that arrived 36 hours after I talked to
>> him. This new cable from Elecraft worked fine, for a while, but then
>> started having the same kinds of problems. I put my old cable that I had
>> lying around back on and it's worked for several months now.
>>
>> I haven't pursued getting a second replacement from Elecraft because it
>> hardly seems worthwhile. In addition, it's not 100% clear to me that the
>> problem is the cable. With the 2 Elecraft cables I've noticed some
>> difficulty in connecting the BNC plug to the BNC receptacle on the back
>> of the P3. Not so with my old cable. The supposition being that the
>> physical dimensions of BNC receptacle on the P3 aren't quite right.
>> Whereas the new cables have a problem fitting, my old cable may be worn
>> enough that it fits anyway.
>>
>>
>> On 8/17/2012 9:00 AM, Gene Trasti wrote:
>>>> P3 with svga
>>>>
>>>> I have a considerable amount of "hash" on my panadapter screen. It tracks the same spot on all bands. All my equipment is very well grounded. I have measured my shack for RFI-it is very clean. I swapped out my switching power supply for a highly filtered one. I even purchased a pretty expensive ac terminal strip with isolation transformers. I have been through the house and have virtually switched off and unplugged everything-nothing seems to help. This hash takes up a pretty healthy portion of the bandwidth. Any sugestions would be appreciated. Is it possible that this could be a problem with the P3 or K3 they are both factory built-although I added the svga board using a wrist ground..
>>>>
>>>>
>>>> Gene. W6jmp
>>> ______________________________________________________________
>>> 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
>>>
>>>
> ______________________________________________________________
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Fred Townsend

Re: P3 Hash

In reply to this post by Jack Smith-6

BNCs are known as constant impedance connectors but what impedance? Usually
it's 50 ohms but there are 75 ohm out there particularly in the video world.
They do have different dimensions but you are not likely to detect the
difference with the naked eye. Jack you are absolutely correct that at least
one Chinese connector company markets both 50 and 75 ohm but with identical
dimensions. These connectors actually measure out at about 62 ohms, a
compromise dimension. The worst part is the oversized parts can damage the
mating connector. Correspondingly some connectors may use soft metal so once
they are spread they are forever sloppy. Caveat Emptor. Buy quality American
or UK connectors and save the headache.
73
Fred, AE6QL

-----Original Message-----
From: [hidden email]
[mailto:[hidden email]] On Behalf Of Jack Smith
Sent: Friday, August 17, 2012 11:03 AM
To: [hidden email]
Subject: Re: [Elecraft] P3 Hash

Some Chinese BNC male connectors don't properly mate with a dimensionally
correct BNC female.

Not sure where the dimensional problem is, but I've run into the problem
more than once.

Jack K8ZOA

On 8/17/2012 1:15 PM, Rowland R Johnson wrote:

> I had the same problem. Replacing the BNC coax cable (between the P3
> and
> K3) with one I had lying around fixed it. Howard at Elecraft tech
> support then sent a new cable that arrived 36 hours after I talked to
> him. This new cable from Elecraft worked fine, for a while, but then
> started having the same kinds of problems. I put my old cable that I
> had lying around back on and it's worked for several months now.
>
> I haven't pursued getting a second replacement from Elecraft because
> it hardly seems worthwhile. In addition, it's not 100% clear to me
> that the problem is the cable. With the 2 Elecraft cables I've noticed
> some difficulty in connecting the BNC plug to the BNC receptacle on
> the back of the P3. Not so with my old cable. The supposition being
> that the physical dimensions of BNC receptacle on the P3 aren't quite

right.
> Whereas the new cables have a problem fitting, my old cable may be
> worn enough that it fits anyway.
>
>
> On 8/17/2012 9:00 AM, Gene Trasti wrote:
>>> P3 with svga
>>>
>>> I have a considerable amount of "hash" on my panadapter screen. It
tracks the same spot on all bands. All my equipment is very well grounded.
I have measured my shack for RFI-it is very clean. I swapped out my
switching power supply for a highly filtered one. I even purchased a pretty
expensive ac terminal strip with isolation transformers. I have been
through the house and have virtually switched off and unplugged
everything-nothing seems to help. This hash takes up a pretty healthy
portion of the bandwidth. Any sugestions would be appreciated. Is it
possible that this could be a problem with the P3 or K3 they are both
factory built-although I added the svga board using a wrist ground..

>>>
>>>
>>> Gene. W6jmp
>> ______________________________________________________________
>> 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
>>
>>

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alsopb

Re: P3 Hash

In reply to this post by rowland

There are 50 ohm and 72 ohm BNC's. They look the same. They differ in
the pin details and dielectric used.

See for example:
http://www.milestek.com/blog/index.php/2011/04/50-ohm-vs-75-ohm-bnc-connectors-explained/

They supposedly can be plugged in to the "other type" without damage.
I'm not sure just what that means.

73 de Brian/K3KO

On 8/17/2012 17:15, Rowland R Johnson wrote:

-----
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2012.0.2178 / Virus Database: 2437/5205 - Release Date: 08/17/12

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Jack Smith-6

Re: P3 Hash

If you look at an HP/Agilent 75 ohm BNC connector you will find it has
no supporting insulation, just the bare spring finger in the female
version or the outer metal shell in the male version.

As far as I have been able to determine from checking dimensional
drawings, BNC 50 and 75 ohm connectors will mechanically mate without
damage. There will be, of course, a bump in the line that may or may not
be of concern.

There may have been some very old BNCs - 1940's vintage - for which the
pins are different diameter but that seems not to be the case for
anything made in recent times.

50 and 75 ohm N connectors, in contrast, do not physically mate as the
75 ohm male pin is smaller diameter than the 50 ohm version. If mated
with a 50 ohm female, the center pin will not make reliable contact.
Worse yet, a 50 ohm male N will splay out the spring fingers in a 75
ohm female connector and damage it.

Jack K8ZOA

On 8/17/2012 3:20 PM, Brian Alsop wrote:

> There are 50 ohm and 72 ohm BNC's. They look the same. They differ in
> the pin details and dielectric used.
>
> See for example:
> http://www.milestek.com/blog/index.php/2011/04/50-ohm-vs-75-ohm-bnc-connectors-explained/
>
> They supposedly can be plugged in to the "other type" without damage.
> I'm not sure just what that means.
>
> 73 de Brian/K3KO
>
> On 8/17/2012 17:15, Rowland R Johnson wrote:
>> I had the same problem. Replacing the BNC coax cable (between the P3 and
>> K3) with one I had lying around fixed it. Howard at Elecraft tech
>> support then sent a new cable that arrived 36 hours after I talked to
>> him. This new cable from Elecraft worked fine, for a while, but then
>> started having the same kinds of problems. I put my old cable that I had
>> lying around back on and it's worked for several months now.
>>
>> I haven't pursued getting a second replacement from Elecraft because it
>> hardly seems worthwhile. In addition, it's not 100% clear to me that the
>> problem is the cable. With the 2 Elecraft cables I've noticed some
>> difficulty in connecting the BNC plug to the BNC receptacle on the back
>> of the P3. Not so with my old cable. The supposition being that the
>> physical dimensions of BNC receptacle on the P3 aren't quite right.
>> Whereas the new cables have a problem fitting, my old cable may be worn
>> enough that it fits anyway.
>>
>>
>> On 8/17/2012 9:00 AM, Gene Trasti wrote:
>>>> P3 with svga
>>>>
>>>> I have a considerable amount of "hash" on my panadapter screen. It tracks the same spot on all bands. All my equipment is very well grounded. I have measured my shack for RFI-it is very clean. I swapped out my switching power supply for a highly filtered one. I even purchased a pretty expensive ac terminal strip with isolation transformers. I have been through the house and have virtually switched off and unplugged everything-nothing seems to help. This hash takes up a pretty healthy portion of the bandwidth. Any sugestions would be appreciated. Is it possible that this could be a problem with the P3 or K3 they are both factory built-although I added the svga board using a wrist ground..
>>>>
>>>>
>>>> Gene. W6jmp
>>> ______________________________________________________________
>>> 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
>>>
>>>
>
>
> -----
> No virus found in this message.
> Checked by AVG - www.avg.com
> Version: 2012.0.2178 / Virus Database: 2437/5205 - Release Date: 08/17/12
>
> ______________________________________________________________
> Elecraft mailing list
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> Post: mailto:[hidden email]
>
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> Please help support this email list: http://www.qsl.net/donate.html
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Jim Brown-10

Re: P3 Hash

In reply to this post by Jack Smith-6

On 8/17/2012 11:02 AM, Jack Smith wrote:
> Some Chinese BNC male connectors don't properly mate with a
> dimensionally correct BNC female.

I'm a member of the AES Standards Committee Working Group on Connectors,
and the Working Group includes representatives of major manufacturers of
audio connectors, most notably Switchcraft and Neutrik. Likewise,
virtually all major mfrs of pro mics are represented in the Microphone
Working Group, of which I am also a member. Most of these manufacturers
have major problems with counterfeits of their products, and dimensions
are only one of the characteristics that don't meet specifications.

Yet another reason for sticking to known quality manufacturers (and
reputable distributors who buy direct from those manufacturers, not
counterfeits) of this sort of product.

73, Jim K9YC
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Don Wilhelm-4

Re: P3 Hash

Good points Jim, but as a group we are a "lazy sort" and many purchase
their BNC coax assemblies from those who offer pre-assembled cables. In
that case, there is no opportunity to specify the connectors - we have
to trust that the cable vendors are using quality connectors in the
cable assemblies that they sell. Unfortunately that may not always be
the case.

I agree that we are hams and should have some element of technical
expertise, and the simple matter of putting a BNC connector on a piece
of RG-58 should not be a problem for us, but the reality is that hams
are more and more becoming "appliance operators" with little skill in
how to assemble things like BNC connectors.

I have done my best to get my grandson Josh KJ4NYI interested in
homebrewing (or at least kit building), and so far the results have been
successful. He has built a K1 and a K2, as well as many of the QRPme
kits, and is currently building a KPA100. He takes pride in his work
and does a really good job of it. I am working with him on
troubleshooting steps and techniques - progress is OK, he does not yet
understand all the theory, but at least he is trying to "put it all
together" which is more than I can say for some of the questions
presented on the common ham radio reflectors which seem to ask - "I
don't want to look in the manual, just tell me how to operate this thing".

73,
Don W3FPR

On 8/17/2012 6:30 PM, Jim Brown wrote:

> On 8/17/2012 11:02 AM, Jack Smith wrote:
>> Some Chinese BNC male connectors don't properly mate with a
>> dimensionally correct BNC female.
> I'm a member of the AES Standards Committee Working Group on Connectors,
> and the Working Group includes representatives of major manufacturers of
> audio connectors, most notably Switchcraft and Neutrik. Likewise,
> virtually all major mfrs of pro mics are represented in the Microphone
> Working Group, of which I am also a member. Most of these manufacturers
> have major problems with counterfeits of their products, and dimensions
> are only one of the characteristics that don't meet specifications.
>
> Yet another reason for sticking to known quality manufacturers (and
> reputable distributors who buy direct from those manufacturers, not
> counterfeits) of this sort of product.
>
> 73, Jim K9YC
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
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>
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> Please help support this email list: http://www.qsl.net/donate.html
>

Bill Frantz

Re: P3 Hash

Nice job of Elmering Don.

I also must have done something right. My son ended up with a
MSEE and still occasionally brings boards around to rework on my bench.

There is something magic about working someone a long ways away
with a rig you built yourself. It must be an even greater thrill
if you designed and built it yourself.

Cheers - Bill, AE6JV

On 8/17/12 at 15:53, [hidden email] (Don Wilhelm) wrote:

>I have done my best to get my grandson Josh KJ4NYI interested
>in homebrewing (or at least kit building), and so far the
>results have been successful.
---------------------------------------------------------------------------
Bill Frantz |"After all, if the conventional wisdom was
working, the
408-356-8506 | rate of systems being compromised would be
going down,
www.pwpconsult.com | wouldn't it?" -- Marcus Ranum

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