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...

Únor 2008

TT Orion 565 on 160m & optimal setting - part V. by YT1NT (AGC threshold comments)

27. února 2008 v 12:01 | Petr, OK1RP |  Operation topics
As I promised last time there I am posting the compilation 
of the comments by Sinisa regarding the AGC threshold 
and principles uses on the Orion 565 receiver.    
I hope it will help to Orion's owners to understand all of 
the neccesary details to be able to effectively use AGC 
setting on their Orions.    
see text as follows:    
 Richard Detweiler wrote:    
> When the noise drops down as the agc threshold is increased,
> what is happening, is the noise is dropping below the point 
> at which the AGC will try to amplify.    
   When AGC Threshold is increased, gain is    
   immediately reduced in the same proportion.    
   No automatic action here, and AGC never "tries"    
   to do anything else apart from maintaining    
   constant volume.    
   There is only one AGC Threshold,    
   and, for any given threshold value,    
   signals above it are attenuated    
   to maintain constant volume.    
   No attempt is made to amplify signals    
   below the threshold, an no attempt is made    
   to improve S/N ratio or anything else,    
   apart from maintaining constant volume.    
> This is a Good thing,  because hopefully the weak signal 
> just above the noise is not below that point and it will then 
> amplify only the signal of interst,    
   This reminds me of a myth about Orion's AGC    
   being fundamentally different from usual    
   implementations, i.e. being able to reduce    
   noise and amplify desired signals.    
   Unfortunately, there is no such a miracle.    
   At instants when both signal and noise are present,    
   signal to noise ratio does NOT depend at all on AGC    
   Threshold setting. And AGC action tends to reduce,    
   NOT increase the apparent signal to noise ratio,    
   as perceived with intermittent signal.    
   Orion's AGC action does not bring anything fundamentally new,    
   although the level of user control is greater than usual.    
   The user may or may not achive optimum settings,    
   depending on skill and willingness to play with controls.    
   By setting the AGC Threshold just above the    
   signal + noise level, AGC is essentially    
   turned off, with two benefits:    
     a) intermodulation between the signal and the noise    
        through AGC action (acting as undesired amplitude modulation)    
        is avoided;    
     b) our aural system doesn't get confused by fast and    
        frequent changes of gain.    
   The sole remaining AGC function is that of    
   protecting our ears from unexpected    
   strong signals. Not a miracle, but useful.    
   Sinisa  YT1NT, VE3EA    
That's all regarding the Orion 565 receiver setting at this moment. 
When I will have some another information then I will post them. 
Do not hesitate to email me if You will have another usefull informations 
or experiences with that tcvr on Topband.   
73, Petr OK1RP   

TT Orion 565 on 160m & optimal setting - part IV. by YT1NT

27. února 2008 v 11:55 | Petr, OK1RP |  Operation topics
by Sinisa Hristov YT1NT, VA3TTN shristov@ptt.yu
Version 0, Feb 28, 2004
Perform the steps in this order:
* initial adjustments,
* start an audio analysis program (optional but very useful),
* set the optimum RX sensitivity for the given environment,
* set AGC to avoid it causing distortion to weak signals,
* adjust filters according to band conditions.
Initial Adjustments
1. Connect and select the desired antenna.
2. Use studio quality stereo headphones (my choice: Beyerdynamic DT-770 Pro or DT-109 headset). Good isolation from room noise is essential.
3. AUDIO menu:
* turn off BinRX;
* set both RX EQ values to 0 dB.
4. RX menu:
* main AGC hang = 0.30 s (for fast contest operation decrease it later to 0.00 s)
* main AGC decay = 5 dB/s (for fast contest operation increase it later to 10-15 dB/s)
* PBT/BW STEP = 10 Hz.
5. OTHER menu:
* all five rates to FAST.
6. FILTR menu:
* XTAL FILTER = AUTO (for CW operation 1 kHz filter provides best dynamic range)
* enable optional filters that are present
* DSP FILTER LENGTH = 199 taps.
7. Set controls:
* select desired frequency
* STEP = 10
* SPOT = desired value (my choice is 600 - 700 Hz; with wide CW filters use 800-1000 Hz)
* RF GAIN = 100
* MODE = desired mode
* NB = OFF
* NR = OFF
* AN = OFF
* RIT and XIT = OFF
* MAIN AF GAIN to a comfortable listening level (disable sub RX AF GAIN)
* select CUT L, rotate the knob to set PBT = 0 Hz for CW and PBT = 150 Hz for SSB;
later in operation: use the knob to cut low-pitched interference on SSB;
* select BW, rotate the knob to set BW = 500 Hz for CW and 2100 Hz for SSB
later in operation: use the knob to adjust CW filter bandwidth or to cut high-pitched interference on SSB.
The ultimate limiting factor in receiving weak signals is noise, and not receiver's "gain".
The total noise power audible from headphones is a sum of:
* internal receiver's noise, and
* external noise coming from the antenna and being received just like any other signal.
Receiver's noise must be weaker than external noise if the receiver is not to degrade reception. It is recommended the internal noise level to be 10-12 dB below the external noise level. This way the internal noise will cause negligible increase in the total noise power. The audible signal-to-noise ratio will be determined solely by external noise. However, there is no point in making receiver's noise weaker than external noise by more than 10-12 dB. Signal-to-noise ratio cannot be improved that way, and the receiver would become more susceptible to overload. The optimum sensitivity level clearly depends on the environment - location, frequency, antenna and propagation. Therefore, a new adjustment is needed whenever the environment is changed. A common mistake is to use the as much gain as available, regardless of actual conditions. This is wrong - too much gain seriously impairs receiver's ability to receive weak signals in the presence of interfering strong signals, thus degrading the effective sensitivity.
The following procedure is specifically tailored to Orion's controls, but the method is the same with any receiver.
Connecting and disconnecting the antenna should result in noise level difference of 10-12 dB (~2 S units).
If RX AUX connector is not used, one can simply press MAIN RX/TX RX ANT key.
Strictly speaking, the antenna shall be replaced by a 50 Ohm termination (on RX AUX connector).
Anything more than 10-12 dB overloads the receiver unnecessarily.
Anything less than 10-12 dB reduces the signal to noise ratio.
Start with full sensitivity and reduce it until the above condition is satisfied.
Orion has 3 sensitivity controls which should be reduced in the following order:
* PREAMP turned off;
* ATTN increased to 6, 12 or 18 dB;
* RF GAIN reduced.
If the external noise moves the S meter sufficiently, one can use its indication which is reasonably accurate and does not depend on AGC THRESHOLD setting.
If the test is done by external instrumentation or by ear, AGC THRESHOLD must be increased slightly above the point where the external noise volume starts to decrease. This ensures that AGC will stay inactive, and what is heard (and measured) will reflects actual power ratios. The exact point is not critical and may be much higher than the minimum one. Of course, the selected setting must not be changed during the test.
The Purpose
The purpose of AGC [Automatic Gain Control] is to avoid overload of ears by reducing the gain for strong signals. Unfortunately, as implemented in Orion and most other receivers, AGC can degrade weak signal reception. AGC essentially divides the signal by a rectified and filtered version of it, creating intermodulation which is particularly bad with a weak signal near the noise level. The signal and the noise get intermodulated, significantly reducing readability. Therefore, the AGC action is undesirable with weak signals. However, AGC must stay on in order to protect ears from unexpected strong signals. The purpose of AGC adjustment is to provide the optimum tradeoff between readability and protection.
Orion's AGC Controls
Orion has four sets of AGC settings: SLOW, MED, FAST and PROG. Each set is independently adjustable with PROG providing the widest range of adjustment.
Within RX menu there are three AGC settings (with separate values for each of the sets):
* AGC HANG time,
* AGC DECAY rate,
AGC is inactive for a HANG time long period after a signal peak that determined the latest gain reduction. During that period the gain is held at a fixed level, resulting in two benefits (until the "hang" period ends):
* the job of our aural system is made easier, in part by not raising noise level between characters/words;
* the usual AGC-induced intermodulation is avoided.
When the "hang" period expires, AGC starts increasing the gain at AGC DECAY rate. Faster rate enables the receiver to recover gain in shorter time, but too fast a rate will reduce readability due to disproportionate increase of noise and interference volume.
AGC THRESHOLD determines the signal level above which the AGC starts to reduce the gain.
On "typical" receivers, RF GAIN control can be used to superimpose DC control voltage (and move S meter) making AGC loop inoperative for signals that do not move S meter anymore. This is a very effective weak signal technique. There is an Inrad flyer recommending its use on FT1000MP. One simply turns RF GAIN counter-clockwise until the S meter stops responding to noise peaks.
Contrary to popular belief, no sensitivity is lost by reducing RF GAIN control in this way, because the actual gain would have been reduced by AGC anyway.
Orion's RF GAIN does not control the AGC threshold directly. Orion users have to activate menus and then select and change the clumsy AGC THRESHOLD setting (which does not move the S meter), instead of simply turning a knob counter-clockwise as on "less modern" receivers. Therefore, speaking ergonomically, Orion's AGC THRESHOLD control is less adequate for the purpose due to:
* lack of correlation between AGC THRESHOLD values and S meter noise readings;
* lack of dedicated knob.
Both disadvantages can be overcome, but the price in time and effort may simply be too high in contests.
Particularly cumbersome is to know "how much of it" to apply, compared to RF GAIN method where one simply looks for a non-moving S meter.
Menu readings are given in microvolts. The manual is not explicit where are these microvolts measured.
One is tempted to assume that they are measured at the antenna connector and can therefore be correlated with S meter indication on the basis of S9 = 50 uV and +1 S unit = doubling the voltage. However, such an assumption is wrong. Despite 0.01 uV resolution, indicated AGC THRESHOLD levels are grossly inaccurate. On my Orion measured AGC threshold levels are ~21 dB below set values with preamp on, and ~9 dB below set values with preamp off.
Sensitivity adjustment must be performed first, as described above.
If the external noise is kept at the same level on various bands (S 3 level is recommended), then AGC settings may also stay the same.
Adjusting AGC THRESHOLD by instrumentation or by ear:
* ensure that sensitivity is correctly adjusted, avoiding noise readings above S 8;
* starting with a low value, increase AGC THRESHOLD until the external noise volume is reduced by ~15 dB (~2.5 S units); external noise will remain comfortably audible, but not as strong as usable signals;
* adjust AF GAIN for comfortable volume.
Adjusting AGC THRESHOLD by S meter:
* ensure that sensitivity is correctly adjusted, avoiding noise readings above S 8;
* adjust AGC THRESHOLD ~2 S units above the S meter noise readings, according to the table above; external noise will remain comfortably audible, but not as strong as usable signals;
* adjust AF GAIN for comfortable volume.
AGC DECAY can be kept at 5 dB/s (slightly faster in contests), with AGC HANG time at 0.30 - 1.00 seconds.
Roofing Filters
The purpose of roofing filters is to protect stages after the first mixer from strong adjacent signals.
Orion repeats the mistake of earlier receivers by overloading the weak stages after the first mixer and then attempting to escape from IM problems by putting in narrow roofing filters, which works down to 1 kHz, but then breaks up after amplification is added with 500 Hz and 250 Hz filters.
The filters work very well, in spite of not being shielded.
Both 500 Hz and 250 Hz filters should be centered. The procedure given in the manual suggests positioning the peak gain point on the spot frequency. This will not work with slightly asymmetric pass bands. It is better to use an audio analysis program and position -3 dB or -6 dB points symmetrically around spot frequency.
Measured Roofing Filter Performance using 200 Ohm termination
insertion loss
-3 dB -60 dB
0.18 - 0.34
0.43 - 0.75
1.10 - 3.15
0.98 - 1.68
3.30 - 5.50
4.90 - 7.00
Interested parties should email me for bandwidth and group delay sweeps in JPG format.
DSP Filters
DSP filters provide Orion's ultimate selectivity. Recommended use of filters knobs is described at the end of "Initial Adjustments" section. Particularly valuable is the ability to change filter bandwidth and to shift the pass band without causing any disturbance to received audio, unlike so many other receivers. It is a widespread myth that a narrow CW filter enables the operator to hear weak signals buried in white noise and not audible with wider filters. This simply doesn't happen, at least not before the bandwidth is reduced very much below ~50 Hz (with slow telegraphy). This comes from the fact that our aural system performs a very good signal processing, effectively narrowing the bandwidth around a CW signal to about 50 Hz. But when the reception is limited by adjacent transmissions (not by white noise), a narrow CW filter can help a lot.
When using a narrow CW filter, it is most important to center the signal inside the filter pass band. Simply switching to a narrow filter may not help, and the desired signal may actually disappear if it is not centered. The centering is usually done using a VFO knob or RIT, aiming for the signal tone equal to the keying side tone. The SPOT key may be pressed to produce a beat note, but that will disturb the reception. A much better method is to use an audio analysis program and center the signal visually using the audio spectrum display. The spectrum display is also very useful for selecting an optimum filter bandwidth according to current conditions, and for adjusting low and high cutoff frequencies during SSB operation in order to optimally separate the signal from interference. It is also useful with the manual notch filter.
Well, it is the recommendation in an excellent article by Sinisa, YT1NT. In the next article I will post also some comments made by Sinisa regarding the AGC threshold values...
As I tested it on the Orion 565 the AGC is quite sensitive on Topband and in my case I had to use threshold values around 63 uV and even sometimes more than 90 uV.
73, Petr OK1RP

Ogasawara 2008 by JD1BLY, JD1BMO and JD1BMP

26. února 2008 v 19:43 | Petr, OK1RP |  Band reports
Ogasawara 2008
小笠原2008プロジェクト - 2008/2/13-28
IOTA: AS-031 / G.Loc: QL17cc (27°5' 2"N , 142°12' 34"E) / JCG#10007


- 小笠原初の144MHz帯500W免許によるEME
JD1BLYとJD1BMPは,すでに,関東総合通信局から変更許可をいただいております.期間中に,変更検査が行われ 144MHz帯500Wおよび50MHz帯1kWの免許を予定しています.EMEは主に2mのWSJTモードで,可能な限りEMEに時間をさきます.EMEへのQRVは,検査後の2/19からを予定しています.
- 160mや80mなどローバンドをメインにQRV
There I prepared short overview in English...
Operators JD1BLY, JD1BMO and JD1BMP organized the DX-pedition to Ogasawara Isl. from 13.-28.Feb 2008.
The main goal is operation on low bands 160/80m, CW so its good opportunity to work JD1 on Topband now.

Sunrise / Sunset time at Ogasawara

Feb. 1321:0908:21
Feb. 1421:0808:22
Feb. 1521:0808:23
Feb. 1621:0708:23
Feb. 1721:0608:24
Feb. 1821:0508:25
Feb. 1921:0408:25
Feb. 2021:0308:26
Feb. 2121:0308:27
Feb. 2221:0208:27
Feb. 2321:0108:28
Feb. 2421:0008:29
Feb. 2520:5908:29
Feb. 2620:5808:30
Feb. 2720:5708:31
Feb. 2820:5608:31
Feb. 2920:5508:32


ICOM IC-756Pro2
YAESU VL-1000(HF + 6m) 1kW
SD1477 x 4 (For 2m EME) 500W
CD 4x211H (4x11elements) (for 2m EME)
CD 7elements YAGI (for 6m EME)
Aki Special (for 160m)
Vertical antenna (for 80m)
2 elements vertical antenna (for 40m)
2 elements Tri-band HB9CV (for 20m to 10m)
DP (for 40m-10m)
GP (for Satellites



QSL Information

We will be able to send our QSL for all QSOs via the Bureau except for your direct request of QSL.
JD1BLY via JI5RPT / Bureau or CBA(Please see
JD1BMO via JE1EKS / Bureau or CBA(Please see
JD1BMP via JM1WBB / Bureau or CBA(Please see

QSL policy

  • SAE (self addressed envelop) + enough postage -> by Direct
  • No SAE or not enough postage -> via bureau
  • QSL request via bureau -> via bureau
  • "Enough postage" means ... (Jan. 2007)
  • AS(HL, BY, HS, VU, YB...etc) = Japanese 90 yen stamps or 1$ or 1IRC
  • NA, EU and OC = Japanese 110 yen stamps or 2$ or 1IRC
  • SA and AF = Japanese 130 yen stamps or 2$ or 1IRC
Good luck on the air.
73, Petr OK1RP

VP6DX - Ducie Isl. on 160m band - News #21

25. února 2008 v 21:56 | Petr, OK1RP |  Band reports
News #21- 2008 Feb 25
Long path contacts on 160m with Ducie Island
Earlier, we reported that a contact on the 160m band had been made with A45XR in Oman, at the opposite side of the planet from Ducie Island. This contact occurred on Feb 18 near Ducie Island sunrise. All of the stations contacted in Europe were in their late afternoon, with the sunset terminator approaching.
On Feb 21 a series of long path 160m contacts were made between Ducie Island and stations in Ukraine and southern European Russia. Eleven stations were worked during 1345-1430z. Signals were best on the 225 (Ukraine) or 195 degree (Russia) beverages and inaudible in other directions, confirming a long path route with very little or no skew.
Contacts with southern European Russia used a path from Ducie Island south-southwest over Antarctica, then north across the southern Indian Ocean (Heard Island, Mauritius), across the Persian Gulf and Iran into Russia. These paths are 23000 to 24000 km long.
For the Ukraine, signals followed a south Pacific Ocean path into the Southern Ocean below New Zealand and Australia, then near the Maldives, the Persian Gulf, and finally towards the Ukraine.
During the same time period, a station in the Moscow City oblast was also contacted. This signal clearly arrived on the short path, crossing over Scandinavia.... Signals were loud on 015 degree beverage antenna and was barely audible on the 195 antenna.
Scandinavia and northwest Russia stations looking for a 160m contact with Ducie Island should check this time for a short path opening. Stations in Ukraine and southwest Russia should look for the long path.
During the hours leading up to and including this long/short path opening to Europe, Oman, Mongolia, and Tajik stations were also contacted on their short path directions.
Of course, we looked for the same opening the following morning, but without success. The 160m operator team will keep checking through the final day of operations. Departure from Ducie Island, now scheduled for February 28 Thursday at 2000z, has been delayed by 1-2 hours so that a final attempt can be made to work more eastern and northern European stations during this unique opening.
Description of stations
We have received inquiries about the equipment and antennas used on Ducie Island.
Each operating position uses:
  • Elecraft K3 radio. The outstanding receiver and transmitter characteristics allow us to run two positions simultaneously on any band -- even the very narrow 30m band -- with absolutely no interference. Good design makes the complex appear simple: the ins and outs of this sophisticated radio were quickly mastered by the operator team, none of whom had seen a K3 before the expedition.
  • Microham microKeyer II computer interfaces: plug in, turn on, call CQ and get to work.
  • Acom 2000, 1000 or 1010 amplifiers: quietly getting the job done without trouble. The position used on 160m includes an OM 2500 HF amplifier.
  • 200 W W3NQN bandpass filters from Array Solutions and 2 kW bandpass filters from 4O3A.
  • WinTest logging software runs on Durabook ruggedized laptops.
  • Honda EM65is and EM30is inverter supply, gasoline generators -- 100% reliability to date. The inverter system has been very tolerant of the widely varying loads presented to the generators as multiple operating positions switch between transmit (high power consumption) and receive (low power consumption), a vast improvement over previous gasoline generator designs.
The seven operating positions are divided into two sites: east (four positions) and west (three positions). The operating sites stand about 1km apart, a 15 minute walk over a coral shelf bordering the island's inner lagoon. Each site has its own WiFi network, and a microwave link ties the two sites together. Sleeping tents and meals are located at the east camp.
The antennas include:
  • 160m: Titanex vertical. (west)
  • 80m/30m CW: Titanex vertical. (west)
  • 75m SSB: SpiderBeam 4-square. (east)
  • 40m: two SpiderBeam 4-squares. (one at each site)
  • 30m: Spiderbeam 4-square. (east)
  • 20 thru 10m: two Spiderbeam 2-element vertical Yagi arrays on each band, one located at each site.
  • 6m: 5-element Yagi
An array of beverage receiving antennas sits mid-way between the two sites. Each beverage is constructed using DX Engineering two-wire beverage kits, providing two directions for each installed antenna. At present four beverages (eight directions) are in available to the 160m, 80m CW and 75m operator. Each operator has independent choice of his receiving antenna. The receive antenna distribution system includes DX Engineering pre-amps, packaged with custom filter, switching, and protection hardware designed and built by K3NA and W2VJN. On-site construction was done under the hot sun by Robin WA6CDR and Milt N5IA (who sacrificed most of their operating time to date to make this happen!)
Receive antenna directions available to the operators are:
  • 015 - western USA, eastern Europe short path. (about 200m in length)
  • 045 - eastern USA, western Europe (two parallel 200m beverages, combined)
  • 085 - Caribbean, northern South America, Africa. (about 350m length)
  • 125 - southern South America (about 200m in length)
  • 195 - long path eastern Europe & Scandinavia (reverse direction of 015)
  • 225 - long path eastern Europe & Scandinavia, Australia, New Zealand. (reverse of 045)
  • 265 - southeast Asia, western Pacific, northern Australia (reverse of 085)
  • 305 - Japan, China, northern Asia. (reverse of 125)
This beverage system came on-line on Feb 16 and has been an outstanding success in reducing tropical thunderstorm static, improving our ability to copy weak signals and look for unusual propagation paths.
All this hardware is here on Ducie Island to help make it easy for you to contact us. No matter how simple your antenna, or distant your location, please check our transmit frequencies. If you can hear us, we can probably hear you -- so give us a call! Even a make-shift temporary antenna should yield some surprising results. But hurry! On-air operations will shut down soon as we prepare to return home.
New pictures online
We would be delighted if DX editors would publish this information as widely as possible and DXers bring it to the attention of their clubs and fellow DXers.
Small test for Topbanders -> WHO IS AT THE KEY ON THE PICTURE IN THE BEGINNING OF THAT ARTICLE ? Your tips You can put to comment below the article...
73, Petr OK1RP

VP6DX - Ducie Isl. on 160m band - News #18

25. února 2008 v 21:53 | Petr, OK1RP |  Band reports
Hello all,
here I am posting some of latest news about VP6DX operation on Topband which I sumarized from their web. Originaly I arranged these informations ownself but Bill, W4ZV was faster so with thanks to him I am using over here his sumary report published originaly on Topband mailing list...
News #18- 2008 Feb 19

m contact made with opposite side of the planet
At Feb 18 Mon 1252z, the
Ducie Island 160m operator was called by, and
completed a contact with, A45XR in
Oman. A45XR is located less than 300 km from the antipode (exact opposite location on the planet) of Ducie Island essentially the most distant location from Ducie Island.

This contact took place during the late afternoon,
Oman time, 1 hour 10 minutes before sunset. At the time of the contact, the terminator was 2000 km from Oman, approaching from the east northeast.

All directions between antipodes are of equal distance. Over what path was this contact made?

At Ducie Island, A45XR's signals were heard best on the 305° beverage antenna. This suggests the signal path traveled over Japan, northern China, and Pakistan... exiting perpendicular from the twilight zone. It is possible a single E-skip hop between Oman and northeast Pakistan completed the path through the 2000 km daylight sector.

Congratulations to both operators!

Now that we have shown Ducie Island's topband operating team can contact even the farthest points on the planet, what's stopping you from trying a top band contact with VP6DX? If you think your antenna is inferior, or you are running limited transmitter power, don't give up! Look at the comments in the guestbook section of the website: lots of stations are now in the VP6DX logbook with very simple antennas and low heights -- event on top band.

So give every band and mode a try. We are waiting for your call!

We will also be listening on 160m for contacts on this path (or some variant). It would be a thrill to put long path contacts on top band in the log. Let's see how far we can push propagation!

Please submit any reception reports for unusual openings, including openings on other bands, via the VP6DX website.

North American 160m schedule
Most 160m operators in North America recognize that, when sun sets at Ducie Island (0300z), it is dark in North America and most of Europe.

Between this time and European sunrise is the only propagation window for contacts between Ducie Island and Europe. Many years will pass before another expedition arrives at Ducie Island at the bottom of the sunspot cycle. As a result, one of our expedition goals is to give as many stations in Europe and Asia a 160m contact with Ducie Island.

To accomplish this goal, North American stations (with much shorter path to Ducie) will need to wait.

Our top band operating team proposes that, on every evening, we will begin making contacts with North America no later than 08z. There is no need for North America top band operators to wait until their local sunrise to contact Ducie Island. 160m is staffed with an operator throughout the night.

As described elsewhere, the team has invested considerable work in an effective receiving antenna system to help us pull weak signals out from the static. Please give 160m a try! We are waiting for your call.
Thank You to Bill, W4ZV for editing the flash news.
73, Petr OK1RP

Telescoping Fiberglass Masts - part IX.

23. února 2008 v 20:51 | Petr, OK1RP |  Antennas
as I promised in last article about fiberglass masts (part VIII.) I should talk about poles from local manufacturers or local distributors in Czech. I did not changed plans to talk about them but not now. The reason is that we have another source available in Europe. Its WiMo antennas distributor who offering his poles here
Let go to see what they have and if its possible to use it as support for our Topband antennas.

Glas fibre mast

Bild Fiberglasmast 10m
Length is 10m, packed in a neat canvas transport bag. Don't compare with the cheap fishing rods! Significantly better and more stable version specially developed for antenna applications. Very firm by using 3-tier lamination, virtually resistant against ultra violet light by means of blackened coloring.
Excellent vertical stability by means of individually cut friction areas. An 8-9 meter high mast supports one 2m HB9CV or a lightweight short wave dipole. Extend or collapse within a few seconds.
This is an ideally suited quick-mast for use on a balcony, in the garden, in vacation or for the field day and in case your landlord doesn't like fixed antenna installations. The set-up time of a wire vertical is typically 1 minute or 5 minutes for a light weight dipole, break-down time 30 seconds!
No foundation is required. Affix on the balcony with a rope or by using tape to fix on the car mirror or attach to a wooden support during field day - that's it! Very easy transport and fits in every car trunk. No problem for air transport carry-on.
Total length 10m, retracted 1.15m. Weight 1.5 kg. Base diameter ca.50 mm, in 9m height ca.10mm.
Order No.

Extension for glass fibre mast

Extension tubes, one meter long with whcih the a.m. mast can be extended at the lower end. Just remove the cap, insert the extension, done. Up to three extensions are possible without guying, beyond that guy ropes are recommended.
Order No.

Spare tubes for fibre glass mast

Single spare tubes for fibre glass mast, please state the lower and upper diameter required when ordering.
Order No.

Low-Cost Fibre glass masts

Our simpler fibre glass masts have the same rigidity as the original, but no friction zones and not reinforcements at the end of each tube, no cloth bag as with the original. Length retracted 1m, extended 4, 6 or 10m.
Order No.
18338.04 4m length
18338.06 6m length
18338.10 10m length
Well regarding the first fiberglass pole 18330 it sounds very nice and 1cm of the diammeter at 10m height could be ok. The main parameter -> material tickness is missing so its hard to say if its possible to use it permanently.
The cost effective second pole 18338.xx seems to be standard fishing pole which is offered by lot of sellers not only in EU. So the question is where the buyer comes from to decide for nearest seller cause of lowest shipping cost.
Also it will be very nice to hear from some of You the experiences with these WiMo poles in the field.
73, Petr OK1RP

VP6DX - Ducie Isl. on 160m band

15. února 2008 v 18:15 | Petr, OK1RP |  Band reports
The DXpedition to Ducie Island
VP6DX, is well underway now and the DXpedition crew has now posted its logs online. Have you worked VP6DX yet? Check and make sure you are listed in their log. There are 21 band slots in three modes (CW, Phone and RTTY) that can be worked. Their Web page also provides the optimum times for working . Depending on weather and other considerations, VP6DX will go off the air on or around February 27.
How to work them on Topband ? Lets go to check available informations about acitvity, frequencies, operation practice etc. on 160m to have chance work them as easy as possible...
160m1827.3 (1)1843.3 +15---
80m3502.5 +253781 (2)---
40m7002.5 +257095 (3)---
30m10106.5 +7---10149 -7
20m14002.5 +2514190 +5514089 -7
17m18072.5 +718165 -15---
15m21002.5 +2521295 +15---
12m24892.5 +724987 -15---
10m28002.5 +2528470 +15---
6m50105 +750145 +15---

(1) RX: JA -10 kHz; Rest of the world: +7 kHz
(2) RX: Americas: 3853 and above; Rest of the world: 3799 and below
(3) RX: Americas: 7228 and above; Australia: 7103 and above; Rest of the world: -15

160m Operations
The goal of the VP6DX 160m operation is to provide DXCC credit for the largest number of DXers. When conditions permit SSB contacts (lower noise levels, stronger signals), conditions also permit contacts with many weaker stations on CW who would not otherwise be able to contact us.
Therefore, 160m SSB operations will be limited as follows:
SSB operations will begin at the start of each clock hour, but only if fewer than 5 QSOS were worked on CW during the previous 10 minutes. SSB operations will continue for 30 minutes, or until the rate falls below 10 contacts in 10 minutes, whichever occurs first.
Reminder: There will be no RTTY or PSK operation on 160m.
Reminder: When 160m is open to Europe, stations in North and South America are asked to QRX. European signals on 160m are much weaker (especially for eastern Europe) and the band will close to Europe a little after 0800z. We do not plan to start working the Americas until after 0800z. After 0800z, we must balance operating time between North America and Asia until the band closes for us.
During our second weekend on Ducie, the CQ 160m SSB contest will be in operation. We hope to take advantage of the extra activity to expand our 160m SSB QSO total.
We will participate in the CQ 160m contest, giving a contest exchange and should be on SSB on 160m during that 48 hour period.
160m26m tall vertical (if we get too bored, we might set up a second one ;-))
Finaly read the comment from Jarda, OK1RD as he already worked them on Topband ...
Hello Topbanders,
let me say a few sentences which the VP6DX topband operation are concerned. Just a couple of day of Dxpedition operation on 160m band, you all would agree with me that, the low band operation of the VP6DX came up to expectations. Their signals from the first day on 160m was excellent, operators know when to go on the air, when to ask for EU only and fully play upon topband opening window towards EU. The operator knows how to pick up station and takes notice of qso confirmation from both sides to make correct 2-way qso. I worked them on all my 3 callsigns and it was really joy to make this type of contacts.
I tested my antennas system of course and confirmed myself again that the 8 Circle has never been overcome by 450m long Beverage, the signals from one were in wee bit weaker compare to Beverage but absolutely clean like on higher bands, at much longer period of opening and listen on loudspeaker.
Thanks to Dietmar DL3DXX is low band VP6DX operation enjoyment to follow. I would end up my report by saying " Who knows he knows ".
Good luck in the pile up..
73 Jarda, OK1RD, OK7XX, OL5R
OK, that's syntesis of available informations I have at this moment. If anybody will have any experiences or tips how to work them on 160m or when etc. then I will be appreciated for emails or put it directly to comments window below an article by clicking to "Přidat komentář"...
73, Petr OK1RP