Top band DX-ing is real ham radio challenge. 160m is also referred as the "Gentleman's band"...
160 meters - DX-ing on the Edge...

Listopad 2010

MW stick vs. Half Sloper antenna receiving test

11. listopadu 2010 v 1:20 | Petr, OK1RP |  Antennas
when I spoke to several DXers about the Mini Whip stick all of them said "uhh, Petr if You are interesting in serious operation on TB then forget it and focus on good RX loops or so".
I do not like to evaluate or reprobate anything (specially antennas) without testing it first and mainly You never know which antenna and when will help you to hear weak signals on the TB so...I have this stick now and there is comparison with TX antenna > based coil loaded 11m high half sloper (see preview article about it)...

22:45  160m  W1MK  S6/sloper  S5/MW  (better s/n on MW)
22:53  160m  N3IR    S3/sloper  S2/MW  (better s/n on MW)
23:20  160m  VE1ZZ  S5/sloper  S4/MW  (the same readability)
23:20  160m  9K2YM  S6/sloper  S5/MW  (the same readability)
23:30  160m  W8FJ    S5/sloper  S5/MW  (better s/n on MW)
23:33  160m  K1VW   S4/sloper  S4/MW  (better s/n on MW)
23:35  160m  TK5IH   S6/sloper  S5/MW  (similar readability)

My personal feeling > in most cases the signal levels from MW were lower but quiter. The s/n ratio was definitely better on MW although the differences was not big sometime. Only in one case (TK5IH) I though that reception is better on Half Sloper because of stronger signal. 

The Mini Whip stick was mounted inside of the house in the attic just 50cm bellow the ridge of the roof. Feedline about 10m of the 50ohms cable down to the radioroom. Half Sloper is mounted about 5m far from the MW using the pipes into the total height of 11m where the base coil and sloped wire is mounted. Feedline is 27m of cable going down to radioroom. No radials yet just copper strap going along the pipes down to ground where it's connected to grounding point.
The distance between both antennas is no more then 5m.

Used radio Elecraft K3 where Notch 900Hz masking used, AGC off, AF gain at 11 o'clock, RF gain at 12:30 o'clock, DSP BW 150Hz (200Hz IF Inrad).

Of course there is no doubt that this stick is not comparable to full size Beverages or full size RX loops like Delta, K9AY or even HiZ phased verticals array but be noted that we are looking for "makeshift" solution compare to noisy TX antennas !

Interesting results...isn't it? What do You think about it?

More information You can find here: PA0RDT or here G3GRO

73 - Petr, OK1RP

W2PM MiniDiamond RX loop by OK1RP - part I.

10. listopadu 2010 v 22:14 | Petr, OK1RP |  Antennas

as I am still looking for the receiving antenna which will allow me to improve the receiving performance on my pocket size QTH (250msq) I was very happy to get construction details and description of receiving loop with name MiniDiamond from Pete, W2PM. I have to say that Pete is real gentleman and he provided a lot of effort to help me with RX antennas. Pete  helped me to understand how to build the very small loops effectively for 160m band.

So after some time I decided to start with building the MiniDiamond loop and as Pete said I am making it as large as possible. All will be posted here step by step according to the progress of building. You will see used hardware, construction, mounting process, measurement and testing of the final product as same as the on-air results. If the antenna will not work then You will be able to check where I made the fault and learn from it to avoid Your own issues.

Today I will show You few pictures from bulding the main cross support.

bamboo tickness
I decided to use bamboo as the main cross support because all the other materials seemed to me worse. Fiber glass poles are too breakable, plastic poles used quite often as potatoes support on the garden are too heavy and short as same as wooden poles. On the picture You can see the used tickness. The only problem was in the local store with finding few bamboo poles enough straight, hi.

Cross mounting support
As the mounting support I used universal plate from the local store. You can see a lot of holes in the plate...great as I did not need to make any hole just decide for right one with the screws.

loop cross
The cross support is already done waiting for mounting the last wooden part which will be screwed on the rotor unit. I hope that it will fit to the old rotor used for light UHF antennas...

transformed for loop 1
Finally You can see the box arrived by snail mail with non-inductive resistor and 900/50ohms transformer units all in nice water resistant plastic houses.

transformed for loop 2
If You are interesting in this RX Loop kit then be noted that they are available for loops, Beverages and also Ewe antennas in different versions like BNC, F connectors etc.

That is all for now and see You soon with some progress with building the loop.

73 - Petr, OK1RP

ZJ Beverages and how it works - part II.

9. listopadu 2010 v 1:45 | Petr, OK1RP |  Antennas

as I promised there I am posting the open discussion about the ZJ Beverages as I found it on the reflector.

TopBand: ZJ Beverage Box Comments and Update de W0AH
from []     [Permanent Link][Original]
To:     <>
Subject:     TopBand: ZJ Beverage Box Comments and Update de W0AH
From: (
Date:     Wed, 5 Nov 1997 16:47:09 -0500 (EST)

On Oct. 22 I posted to the list that I was not happy about the performance of
my NE beverage and also that my ZJ Beverage Box was not working and that I
was going to try and fix it.
     Several wrote and asked me to send them any information I received since
they also need ed to fix the ZJ beverage box.  Therefore, this post.
     First, I want to say that my ZJ beverage box worked fine when I first
installed it a couple of years ago.   It brought my beverage signal up 2 or 3
S-units as I recall.  I had no intermod (I have no local commercial
stations).  Using a coaxial hand switch between the transmitting antenna and
the beverage (my transceiver  had no separate receive antenna), I  forgot to
switch the antennas and ran power into the ZJ box.  
      I wrote ZJ, which a month later sent me a replacement device, gratis.
Now, over a year later, wanting too repair the ZJ box, I can not find the
device he sent me.  Thus my inquiry to the list recently.
    My ZJ Box did not come with a schematic which is my main complaint.
Looking at the device, I thought it was a gasfet, but I have been informed by
KM1H, W8JI, and K0CS that it is a MMIC.  MMIC stands for Monolithic Microwave
Integrated Circuit Amplifier.  I have built several of the well regarded Down
East Microwave kits (for 902, 1296, and 2304 MHz) which use MMICs.  Both KM1H
and W8JI wrote that the MMIC was a poor choice for a 1.8 MHz preamp.  I agree
that it is an odd choice, but my Avantek Semiconductor Data Book shows that
the power gain and other MMIC specs are flat from about 0.1 to about 1 or 2
GHz, depending on the specific device. Also, the Avantek power gain versus
frequency chart shows them being flat to DC!   Therefore, the device should
be suitable for 1.8 Mhz.  
     KM1H siad there had been a discussion of the ZJ Beverage Box which can
be found in the archives. So more information is available there.  He also
said that the ZJ  Boxes had been shipped with "at least 4 different" MMICS
including the MAR1, MAR3, and others. He stated that some of those devices
needed different biasing.  He also stated the ZJ Box was subject to overload
and IMD.  Carl said the "ultraminature 9:1 balun is just as bad."  
W8JI suggested replacing the MMIC with "a regular CATV transistor."
     W4MPY wrote that his ZJ beverage box filled up with water and that he
has tried unsuccessfully to get help from ZJ.
      Both W8JI and KM1H stated that a good beverage will not generally need
a preamplifier.
      K0CS kindly sent me a MAR-3 device which had been supplied by ZJ as a
replacement device.
      Looking at the various Avantek MMIC specs (I can not find my cross
reference to compare the Avantek MSA MMICs to the MAR MMICS) I see several
MMICs with very similar specs (in some cases just different plastic packages-
ie. cases).  Almost all of them require 4.5 to 5.5 volts DC.  I suspect the
several different MMICs supplied in the ZJ boxes have identical specs at 1.8
MHz and that biasing is not an issue.  For those who need to replace the
MMIC, a MAR-1, MAR-3 or equivalent should work fine.  MMICs are listed in
several of my electronic catalogs for about a dollar each.
     I hope the above is useful information and that some of you get your ZJ
beverage boxes back up and running.  Unfortuately, mine still is not working
after I replaced the MMIC.  I suspect that the ultraminature balun, as KM1H
described it, needs replacement.  Not sure I want to proceed until I get a
schematic.  Does anyonwe have one?
See also my next post on beverage transformers.
Doug  W0AH

TopBand: ZJ Beverage Box MAR3 MMIC Replacement?
from [km1h @]     [Permanent Link][Original]
To:     <>
Subject:     TopBand: ZJ Beverage Box MAR3 MMIC Replacement?
From: (km1h @
Date:     Thu, 23 Oct 1997 18:58:41 EDT

On Thu, 23 Oct 1997 15:44:36 EDT W0AH <> writes:
>Thanks K0CS for the info that the ZJ Beverage Box uses a MAR3 MMIC,
>which are
>quite inexpensive .

Wrong info Doug. Your ZJ "thing" has a MAR-1 in it according to ur
Owners have found at least 4 different MAR MMIC's so far. NOT
interchangable without changing bias resistor either.

As discussed here at length a month or so ago, the choice of device PLUS
the matching xfmr in the ZJ box makes it an all around poor choice for
Beverages. Nice and cute toy but no good for real world use.
Suggest you check the Archives for comments by users, W8JI, myself, etc.

73   Carl  KM1H

  I thought I had a MAR3 around here, but can't
>find it.
>Can any of the following Avantek be substituted for the MAR3?
>Avantek 0185, 0285, 0485, 0685?????
>I'll post a message as to how this all turns out as others have
>contacted me
>concerning their non-working ZJ Beverage boxes.
>I have the above.  If no answer, I'll try to call WB5LUA, Mr. MMIC!
>Doug  W0AH

Well any other experiences with this system even negative are welcomed over there.

73 - Petr, OK1RP

ZJ Beverages and how it works - part I.

9. listopadu 2010 v 1:38 | Petr, OK1RP |  Antennas

when I discussed some time ago about the Beverages and neccessary boxes I mentioned that one of my Beverage sets is W2ZJ system. After several emails received from some of You I decided to scan the user guide as it is not available on the internet.

I have not enough time to replying to each of You for questions about ZJ Beverage it is designed and which parameters it has.

So there are all information I have and let's go to check it guys.

I am planing to install the ZJ boxes and test it as I heard a lot of negative reviews about it. On the other hands it's promissing the system with pre-amp on the Beverage side then sigs going to shack enough strong and filtered.

As I need the strong negotiation with neighbours to install the 164m of insulated wire on the 2m stands in country side I am not sure when I will be ready to test it.

Does anybody used ZJ Beverages and how it worked for You please?

73 - Petr, OK1RP

Inverted L for restricted space...

9. listopadu 2010 v 1:14 | Petr, OK1RP |  Antennas

when I looked for more information about my antenna (base coil loaded half sloper) I found interesting antenna also for restricted space.


In fact the vertical part is helical vertical where 11.7m of insulated 2.5mmsq wire is wounded on the 5m of the fiber glass pole including the wire going to point A for feed line. The spacing for the winding is approx. 1.5cm.

The 2x 18.1m of the insulated wire used for radials on the ground is compromised solution for that installation. Definitely it's needed better grounding system and 16x 16m is recommended as minimum where 3dB loss is expected.

Well I did not tested it but for those who are space limited it can be inspiration for experiments.

Do not hesitate to share with us Your experiences with compromised antennas like this.

73 - Petr, OK1RP

VP8ORK - South Orkney by James, 9V1YC

4. listopadu 2010 v 0:14 | Petr, OK1RP |  Band reports
VP8ORK Press Release #3 - The Low-Band Plan

Many have been asking about our low-band plans for the upcoming VP8ORK South Orkney DXpedition in January 2011. With antennas to cover 75, 80 and 160m simultaneously from sunset to sunrise, dedicated receive systems and top-of-the-line radios, we will be active on all these bands, every night, for almost two solid weeks. Rest assured that we're giving the low-bands a top priority.

Of course this doesn't mean we're ignoring 40m and up.  It just means we're putting in a bigger effort than usual on those bands where the need is greatest.

We realize that lone operators at remote polar science stations often have limited time and equipment to make an effort on every band, let alone 80 or 160. This is why the big Antarctic DXpeditions are there to fill in the gaps. These expeditions offer experienced DXers a chance at working some new band-modes, and newcomers a chance at climbing the honor-roll.  

Here is a listing of our low-band arsenal:


160 transmit    
The Battle Creek Special (160 main)
85 foot vertical wire supported by Spiderbeam telescoping pole (160 backup)

80 transmit    
SteppIR vertical with 80 meter coil (CW) (80m)
60 foot vertical wire supported by Spiderbeam telescoping pole (75m)
60 foot vertical wire supported by second Spiderbeam telescoping pole (backup)

160/80 receive          
DX Engineering 4 square with DX Engineering preamp and DX Engineering splitters to feed 3 low band radios.
Two RX beverages as an option to 4 square dependant on circumstances encountered on site.


7 x K3 transceivers  (sponsored by Elecraft)
3 x Acom 1010 amplifiers  (sponsored by Acom)
2 x Acom 1000 amplifiers (sponsored by Acom)


EY8MM, K9ZO, ND2T, 9V1YC, K0IR, N1DG, W3WL, K6AW, N6MZ, N4GRN, WB9Z, W7EW, and VE3EJ

I'm sure most of you recognize these calls.  This team brings with it an unprecedented amount of experience in Antarctic DXpeditioning, contesting and low-band knowledge to ensure that all bands are covered from start to finish.

But, even with a great plan, the best equipment and experienced operators, activating the remote entities of the Southern Ocean is still one of the most challenging aspects of amateur radio. These islands are some of the windiest, coldest and roughest places on earth to survive, and just reaching them is an achievement in itself.  Its no secret that private, non-governmental Antarctic expeditions come at an astronomical cost, and without support from everyone within the DX community these trips would simply not happen.  

We're extremely grateful to have major DX foundations such as the NCDXF, INDEXA and the ARRL funding us with large donations.  We're also thankful to have support from many worldwide DX clubs and commercial equipment sponsors such as Elecraft, Acom, DX Engineering and SteppIR.  But even with all that, and each team member contributing over $12,000, it still doesn't even come close to covering the massive expense of a polar expedition.  We need financial support from all of you.

If you haven't sent in a donation yet we hope you will consider joining those who have already stepped up to help.  Our website <> gives full details of our trip, and is where you can contribute at whatever level you feel comfortable.  

We look forward to working you on all bands!


James Brooks, 9V1YC
The Microlite Penguins DXpedition Team
VP8ORK South Orkney 2011

Unfortunatelly I have not so much time to make compilation by myself so I decided to post it exactly as it was released by James on Topband mailing list. I hope that it will help to people who are not subscribed to the list...

73 - Petr, OK1RP