Bjorn, Tim:
Thanks for your comments.
I don't have much time to play with the antennas until the weekend, but I
did manage to hook up an SWR Analyzer. The analyzer says 1.5:1 at 1820 Kc
(35 ohms R). So, there is an antenna out there.
A need to clarify that the noise level is the same between the INV-L and
EWE when I use the EWE preamp. Without the preamp on, the EWE noise level
is almost nonexistent.
A did notice something. With the coax cables on my other HF antennas, when
I unscrew the shield connector and break shield contact the noise rises
significantly but goes to nothing when the shield is screwed back on. This
does NOT happen when I disconnect / reconnect the PL-259 shield connector
on the cable.
Re-orienting the EWE to be "in front" of the INV-L isn't possible right (I
have only an acre). What I may do is take down the EWE and put it up in
the front yard where it will point N/S. I really would like the EWE for
EU DX, but if it's not working, then a N/S attempt may be in order.
73 Mark K3MSB
On Thu, Dec 10, 2015 at 9:31 AM, Tim Shoppa <tshoppa@gmail.com> wrote:
> I would like to concur with SM0MDG's comments about receive coax
> connections. I betcha the OP's system is leaking in at levels way higher
> than the Ewe actually produces. I know everyone loves to detune their
> transmit antenna, but there's no way an Ewe should sound noisier than the
> inverted L.
>
> A reversible array is far and away the best way to convince yourself that
> you have a working receive antenna system. If you reverse it and nothing
> ever changes, well, you're listening to some other antenna! Some (e.g. YCCC
> array) are supposed to be far more sensitive to near-field metal objects
> than others (e.g. K9AY loop) but even then I'm sure you'll be able to find
> a convincing F/B on known BCB stations once you have stuff working right.
> Another useful beacon is W1AW code practice at 1802.5.
>
> Tim N3QE
>
> On Thu, Dec 10, 2015 at 9:19 AM, JC <n4is@comcast.net> wrote:
>
>> Hi folks
>>
>> I would like to add some comments to receiving antennas issue. Any
>> resonant thing (wire, cable, rotor cable tower, TX antenna...) will
>> interact with the RX antenna if they are in the same polarity, different
>> polarity has 27 dB or more of isolation due the polarization itself.
>>
>> The inverted L is easy to detune, just open the wire from the coaxial and
>> check the noise on the EWE. The noise on the RX antenna needs to decrease
>> one or 2 S units. However, it is possible you will not see any difference.
>> The reason is that you may have another point where common noise is
>> deteriorating the directivity of the RX antenna. If it work, just add a
>> relay for detuning the Inv L during RX.
>>
>> The integration with the inverted " L " TX antenna is the easy one do fix
>> the others resonant "things" could be difficult to recognize. Example, if
>> you have a low dipole or elevated radials, these "things" will destroy any
>> directivity of nearby RX antennas, and nearby distance on 160m means 300ft
>> or more, one wavelength. Rotor cable, VHF or other's 120ft feed lines could
>> be resonant and a good reflector for noise and re-radiate them too.
>>
>> Lack of good ground (or no ground at all) is receipt for failure on RX.
>> Running the cables outside the tower and far from the ground is the
>> preferred way to screw things up.
>>
>> I am following every installation of my WF's and there is an issue very
>> frequently found. It is bad connectors contact with the cable shield. Cold
>> solder, no solder, little copper wire on the braid. One single point with a
>> bad shield can ruin you RX system.
>>
>> Doug Waller when he build the first WF was very disappointed with the
>> results until he found a RCA connector with one RCA ear not contacting
>> the preamp input RCA female. Just one little gap in ear with no contact was
>> enough to leak noise into the preamplifier input. After fixing the bad
>> contact, the RX antenna started to work with good directivity. PL259 or a F
>> connector with bad contact with the braid can cause several S units of
>> noise.
>>
>> Spending big money on the radio and do not care about the quality of the
>> connectors used for RX is no sense.
>>
>> Open frame relays (not coaxial relay), open contact switches, plastic
>> boxes are the most common points to add noise and destroy the directivity
>> pattern.
>>
>> Running cable outside de tower and ground them at the base is not a very
>> popular solution. It is hard to run the cables inside the tower they say.
>> As a result RF is everywhere in the shack. No solution for that too.
>>
>> I am just trying to help, there is no free beef regarding good RX systems.
>>
>> 73's
>> JC
>> N4IS
>>
>>
>>
>>
>>
>> _________________
>> Topband Reflector Archives - http://www.contesting.com/_topband
>>
>
>
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