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Re: Topband: 2-element receiving arrays

To: VE6WZ Steve <ve6wz@shaw.ca>, Frank W3LPL <donovanf@starpower.net>
Subject: Re: Topband: 2-element receiving arrays
From: David Aslin G3WGN <david@aslinvc.com>
Date: Sat, 1 Apr 2023 20:41:45 +0000
List-post: <mailto:topband@contesting.com>
Steve, 
This is really helpful.
One point of clarification: now that the 12V is not traversing the coax, what 
power source are you using? Solar panel + battery, or other?
73, David G3WGN M6O

-----Original Message-----
From: VE6WZ Steve <ve6wz@shaw.ca> 
Sent: Saturday, April 1, 2023 12:35 AM
To: Frank W3LPL <donovanf@starpower.net>
Cc: topband <topband@contesting.com>
Subject: Re: Topband: 2-element receiving arrays

I received a few private emails asking similar questions about my power 
redesign of my amps.

I need to clarify this.
Yes, I have redesigned a version of a HI-Z amp that does not use 12v on the 
coax. Each require a dedicated 12v supply line.
I right now have about 15 of these amps deployed in the field for my new BOG 
broadside phased array system.

I have not yet swapped out the amplifiers on my 9C for a redesigned model 
because so far they have remained noise stable. However, all the amps in my 9C 
have had the PCB judiciously cleaned and carefully coated.

Another question was have I actually seen this noise problem from micro-arcing?
The answer is yes. Absolutely.  In some cases it became very bad. In all cases 
this was on poorly cleaned and un-coated  PCBs that developed moisture. On at 
least 5 of the amps I could actually see what looked like galvanic corrosion 
developing at the F-connectors on the PCB. A white dusty powder had developed 
across the connector.  This was not because of serious water intrusion, but 
just moisture and humidity developing in the boxes.  If some day I switch out 
the amps I have now, I will not use a bias-T voltage supply.

As for modifying the combiner not much is required except to snip the RFC at 
each f connector and supply 12v through an RFC to the supply line going to each 
amp.

Steve, Ve6wz 


From Babcocks iPhone

> On Mar 30, 2023, at 6:31 PM, VE6WZ Steve <ve6wz@shaw.ca> wrote:
> 
> I strongly second Franks comment about weather proofing.
> 
> Equally important on any outside electronics is to very carefully clean ALL 
> the residual flux off the PC boards, and especially on the F-connector solder 
> pads.
> ALSO, apply some acrylic conformal coating on all outdoor PCBs.
> 
> With 12v on the coax line with a bias-T setup, even small amounts of dirt 
> stuck to old flux and then combined with moisture can cause serious noise 
> issues with micro conduction between the centre conductor and ground pads.
> 
> I have since redesigned all my rx amplifiers to use a separate 12v dedicated 
> supply voltage to keep the DC off the coax.
> 
> 73, Steve Ve6wz
> 
> Sent from my iPad
> 
> > On Mar 30, 2023, at 2:18 PM, Frank W3LPL <donovanf@starpower.net> wrote:
> > 
> > Tiler,
> > 
> > Congratulations on your new five circle YCCC array! 
> > 
> > Be sure you very effectively waterproof all of your coaxial cable 
> > connectors that carry DC power. Even the slightest amount of 
> > moisture in the connectors will cause micro-arcing of the DC voltage, 
> > raising your noise floor by many dB.
> > 
> > 73
> > Frank
> > W3LPL
> > 
> > 
> > From: "K3MM" <k3mm@verizon.net>
> > To: "Frank W3LPL" <donovanf@starpower.net>, "topband" 
> > <Topband@contesting.com>, "PVRC" <pvrc@mailman.qth.net>
> > Cc: "Pete N4ZR N4ZR" <pete.n4zr@gmail.com>
> > Sent: Thursday, March 30, 2023 8:08:42 PM
> > Subject: Re: Topband: 2-element receiving arrays
> > 
> > I just completed building a YCCC nine Circle array using V E6WZ PC boards 
> > with the latest mods, including on board chokes. I actually have it 
> > deployed currently as a five circle As I’ll be taking it down soon for 
> > mowing season, but it works quite well. The patterns on all three bands, 
> > 160 through 40 are as advertised. Very good patterns but not the best 
> > sensitivity . I built mine as about 23 foot verticals. I’d say compares 
> > favorably to my 500 foot beverage, antennna although it requires a lot of 
> > pre-amplification. Due to the active electronics it can be overloaded by 
> > close transmit antennnas so perhaps not as useful for a multiband operation 
> > in a small area. 
> > I’m providing power over the coax cable and using green heron everywhere, 
> > wireless remote control, which works quite well and is controlled by the PC 
> > software using a mouse or hotkeys. 
> > 
> > It was a fun project. It turned out quite well, but not in expensive. I 
> > scrounged about half the aluminum tubing and angle I’m using for the bases 
> > and probably spent $1500 or so. including the remote control hardware. next 
> > fall, I’ll deploy the full nine circle array, but the five circle is 
> > probably almost as useful and avoids some complexity and cost. i’ll also 
> > probably relocate it to get more separation from some of the transmit 
> > antennnas. 
> > 
> > Ty K3MM
> > 
> > [ 
> > https://apps.apple.com/us/app/aol-news-email-weather-video/id6461006
> > 61 | Sent from the all new AOL app for iOS ]
> > 
> > 
> > 
> > On Thursday, March 30, 2023, 1:38 PM, Frank W3LPL <donovanf@starpower.net> 
> > wrote: 
> > 
> > 
> > Hi Pete,
> > 
> > For a monoband receiving array, you might consider using low 
> > impedance resonant verticals rather than high impedance verticals.
> > 
> > The primary advantages of high impedance verticals are
> > - very short verticals (but taller verticals produce stronger 
> > signals)
> > - multi-band operation
> > - no radials
> > 
> > The primary disadvantages are
> > - reliability issues with outdoor electronics
> > - lightning susceptibility of outdoor electronics
> > - higher cost
> > - much lower signal levels
> > - extreme care required to suppress common mode signals (buried 
> > feedlines are highly recommended)
> > - negative effects of nearby trees and buildings. 
> > 
> > The primary advantages of low impedance verticals are
> > - much stronger signal levels
> > - much less criticality of common mode signal suppression,
> > - much lower cost
> > - much higher reliability
> > - immunity to lightning damage
> > - much less affected by nearby trees and buildings
> > 
> > The primary disadvantages are
> > - taller verticals (typically about 24 feet)
> > - radials (they can be very short if many radials are used)
> > - mono band operation (switchable matching networks can be used for 
> > multi-band operation). 
> > 
> > I highly recommend the DX Engineering Receiving Antenna Phasing System. 
> > Its expensive but well worth the investment especially for a small array. 
> > 
> > [ https://www.dxengineering.com/parts/dxe-ncc-2 | 
> > https://www.dxengineering.com/parts/dxe-ncc-2 ]
> > 
> > If you have 120 feet for a three element array, the YCCC array is a 
> > great choice It can use high impedance or low impedance verticals 
> > Unfortunately its no longer available from DX Engineering The nine 
> > element YCCC array uses only three active elements at any time, so 
> > its really a three element array switchable in many directions.
> > 
> > [ 
> > https://static.dxengineering.com/global/images/instructions/dxe-yccc
> > -switch.pdf?_gl=1*1cv0fc9*_ga*MjEyMDA1Nzc3MS4xNjUyMzAyMjc0*_ga_NZB59
> > 0FMHY*MTY4MDE5NTk1OC40My4xLjE2ODAxOTYwNTYuNTAuMC4w | 
> > https://static.dxengineering.com/global/images/instructions/dxe-yccc
> > -switch.pdf?_gl=1*1cv0fc9*_ga*MjEyMDA1Nzc3MS4xNjUyMzAyMjc0*_ga_NZB59
> > 0FMHY*MTY4MDE5NTk1OC40My4xLjE2ODAxOTYwNTYuNTAuMC4w ]
> > 
> > [ https://www.youtube.com/watch?v=dl-crM5Kb6A | 
> > https://www.youtube.com/watch?v=dl-crM5Kb6A ]
> > 
> > [ https://www.youtube.com/watch?v=lVW1CmrzP7c | 
> > https://www.youtube.com/watch?v=lVW1CmrzP7c ]
> > 
> > A two element array occupies only 60 feet or even a little less. 
> > 
> > 73
> > Frank
> > W3LPL
> > 
> > 
> > ----- Original Message -----
> > From: "Pete N4ZR N4ZR" < [ mailto:pete.n4zr@gmail.com | 
> > pete.n4zr@gmail.com ] >
> > To: "topband" < [ mailto:Topband@contesting.com | 
> > Topband@contesting.com ] >
> > Sent: Thursday, March 30, 2023 12:54:30 PM
> > Subject: Topband: 2-element receiving arrays
> > 
> > Thinking ahead to next winter on 160, I'm interested in replacing my 
> > K9AY Loop with a 2-vertical phased array. I'd like to homebrew the 
> > antennas and just buy or build the remote control unit for the shack.
> > I'm looking for sources of components (antenna-located preamps and 
> > an in-shack controller), and would prefer not to completely homebrew 
> > them, but the prices at the usual suspects are awfully high. Any ideas?
> > 
> > I have pretty reasonably-priced access to 25 and 31-foot fiberglass 
> > poles (used for wind-socks by model airplane enthusiasts). I'm 
> > thinking that one relatively low-cost approach might be to attach, 
> > say, #14 wire to the poles, with preamps at the base, but wonder if 
> > there is a downside to using such small-diameter antenna elements 
> > rather than 1 or
> > 1.5 inch tubing? Alternatively, are clones of the DX Engineering 8' 
> > short verticals with preamps a good alternative? 
> > 
> > --
> > 73, Pete N4ZR
> > _________________
> > Searchable Archives: [ http://www.contesting.com/_topband | 
> > http://www.contesting.com/_topband ] - Topband Reflector
> > 
> > BQ_BEGIN
> > 
> > 
> > 
> > BQ_END
> > 
> > 
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