Nostalgia; Radio & TV Broadcast Antennas

Current summer weather does not allow for weekend HAM projects. Being that ”radio-nerd” doesn’t mean I do not actively enjoy sunshine and outdoors activities like sports. In fact I do and I care less about the missed opportunity to HK and JY on 6m these last few days (new ones so, do I really???).

Anyway, while swimming in Bückeburg (Germany) I noticed a typical classic german Radio& Television tower in the background. This kind of view brings back early memories of our summer holiday car travel to Switzerland, Italy or Austria, during which I spotted many of those Radio/TV towers along the german highway (Autobahn).

During the trip home we passed this one more closely while taking an alternative route(B65) to the Autobahn (A2). This Radio&TV tower is situated on top of the Jakobsberg near the city of Porta Westfalica. More detailed info on the geographical site and the tower can be found on:

http://de.wikipedia.org/wiki/Fernmeldeturm_Jakobsberg#Neuer_Fernmeldeturm


According this website: http://www.senderfotos.de/nrw.htm , the site is open for public. This 135m high tower can be visited at the first level (25mtrs). The two large surroundings are at 50 and 58m height.

Before the closing down analogue TV it served:
ZDF UHF ch 26/300KW
WDR UHF ch57/330KW
NDR UHF ch54/20KW
These analogue transmitters have been shutdown since may 2006, from which DVBT was started.

Today the tower serves:
95.7MHz FM "Radio westfalica"
WDR-Bouquet 1 UHF ch26/5KW
WDR-Bouquest 2 Bielefeld UHF ch31/5KW
ZDFmobil-Bouquet UHF ch33/5KW

Getting the most out of your rig; the TS570SG modification

One is never satisfied....

Making that QSO on 50Mhz largely depends on being there at the right moment.
However, some rigs offer that tiny bit of extra performance which is sometimes needed to hear the other guy at all.

I always enjoyed the ergonomics and user interface of the TS-570SG. This medium sized rig is a joy to use and easy to carry during holidays. I use it already for two years now as my main 50Mhz rig.
In order to enhance its performance I opted for two modifications:

• Exchange the std 2400Hz SSB filter for an Inrad 2100Hz
• Add a temperature controlled crystal heater from Kühne Electronics (DB6NT)
  

Installing the SSB filter
The original Kenwood 2400 Hz (YK88S) is taken out and exchanged for the Inrad 2100Hz (#94).
The '2100' offers better sound quality thanks to a near optimal filter shape. Its bandwitdh is a perfect balance between the std. wide 2K4 and the thin sounding 1K8.

The TS-570 does have one optional filter slot, but that is already taken by a 400Hz Inrad CW filter.




The filter is installed upside down, using insulating material and hot glue.Two customized pieces of RG316 are been used to connect it to the pcb.


Installing the crystal heater

At http://www.kuhne-electronic.de/en/shop/155_Crystal_Heater
you will find all info on this 13 euro (only) product.
Just slide it on the crystal of your main LO and apply hot air to let the heath shrink tube do its job.



How does it perform?
I was able to make a qso with this S7 YU-station on 6m while another SV-station S9+20 was at only 1.5Khz above. Subjectively this is surely different from the past. But since I cannot do an A/B comparison this means ZILT. It only proves that the SV station had a clean signal.


Epilogue
I have been very active on 6m these last two weeks since Es propagation has just started.
I managed to work: I, 4X, SV, ON PA,UR,LZ, LX, DL,EA,CT,YO,LZ,YU, HA, OM, SP,4L, ES,OH,YL,EA8,ER,CU,IS,9H,EI,EA6
Inter-continental: KP4

Am I happy?

No, not entirely.
The TS570 still does not sound optimal. I know it suffers from some phase noise and this is shown by the fact that I have a hard time hearing the other station. It is buried in noise and garbage. The other stations are worked on first or second call with 100W. A soon as I can hear them I can work them easily. But on many occasions I cannot read their reply or report. Very frustrating. Changing settings on the rig does not help. Using the calibrated SSB Electronics masthead preamp doesn't help either.

Picked up an IC-746 with Inrad filters from a friend who does not use it. I have had such a rig in the past too; they are very very nice to operate at 50Mhz and 144. Within minutes during a hectic Es bandopening I'm on a roll; this is just wat is needed.
The Icom is in a different league. Both on reception quality and ergonomics it does for me what it takes on 6m; quick and versatile operating options. RX is better, now I can hear into the noise layers and hear dx at sub-consious level.

Wkd: V4, 8P9, TA, EA9, T9 (again 2 new countries :)

RX Audio Interface to your PC

Whenever doing AF analysis with help of any audio spectrum analysing software at your pc, you're probably facing several interfacing issues:

• 50Hz hum
• RF interference from various sources
  
• Bad ground/ ground loops
• gain/impedance mismatching

The first 3 are referred to as 'pin 1' issues in the world of professional audio. In one word, proper grounding architecture & shielding, or the lack of.
Mind you, the audio input on your sound card is usually already a disaster having bad or failing ground contacts. Next the pc has analogue and digital circuitry, there's a cable to your TRX and there it is susceptible to RF. Not to mention the many ground loops etc..

I have been successfully using Spectran, a freeware audio analyser programm by I2PHD and IK2CZL.
When the audio is directly linked to my sound card input you get the below result (volume settings at zero):



My sound card is an old 16bit Soundblaster compatible type. Any current 192KHz/24bit High-End sound card will lower the noise floor by some additional 10 -15db. For the required measurements this old 16bit card has proven to bemore than adequate.

How to get a 'clean picture'

• Use properly shielded cable
• Install an audio isolation transformer

To conquer the 'pin-1' issues I opted for an audio isolation transformer. These usually are 600 Ohm, which might introduce small mismatches. I terminated its output, added some RF filtering on the output and finally put it in a box with both 3.5mm Jack as well as std RCA in-/outputs:



With the RX Audio Interface inserted (as near at the sound card input as possible), you get the following result:

SteppIR @PI4TUE- part 1

Last weekend we started building the SteppIR 3el yagi for our clubstation PI4TUE at the University of Eindhoven. On the above pic: on the right front Aurelio, PC5A, on the right back Rens, PA3FGA and me in the left corner.


First all parts are checked.


Glass fibre tubes are treated with rough sandpaper in order to create a better grip.



Boom and motor sections are ready & tested.

Next action:

• Remove current Fritzel FB33 yagi from the roof (220ft AGL)
• Install new SteppIR 3el yagi
• Install new coax cable

That 'other' radio hobby...

"FIRATO" at the RAI exposition in Amsterdam

From 1950 till 1998 the Amsterdam RAI exposition centre hosted the Firato every two years. This was a consumer electronics show, mainly focussing on Hi-Fi and TV&Video.
Several new introductions took place at the Firato, like:

• 1963: The second national Television Channel (NED 2)
• 1963: The Philips Compact Audio Cassette
  
• 1967: Colour television by Philips
• 1978: Text view by the BBC
  
• 1982: Compact Disc by Philips

From the 90's onwards, people slowly lost interest in Hi-Fi and TV/Video. Home computer slowly took over...
During the period 1978 till 1985 I had a great interest for Hi-Fi. Every show I dragged tons of folders and stuff :)
I have been drooling at the top models of Philips Hi-Fi equipment, which at that time were accordingly high priced. Definitely not in my league, not even with my saturday-job at the local gas-station. It was mainly Akai I could afford and which suited me very well.



From early 2006 onwards I have slowly started collecting some of those legacy Philips products.
Local Flea markets and internet are superb for this. Even E-bay is useful, as I have collected rare Philips products for only 25 euro. These beautiful products did cost some 700 euro, back in 1979.



Philips AM/FM tuner type 22AH105 and Amplifier type 22AH308








The second CD-player ever: CD300, a second '105'tuner and a receiver 22AH306.
There is more; like a record player and , and.....etc.

Short note: this is all in my shack. Not the living-room.






Dating from 1978; the 22AH794 receiver, accompanied by the '541' Motional Feedback active loudspeakers (1976).
I own several 'Philips MFB' loudspeakers. What makes these special is that the typical non-wanted woofer cone movements (in and out-swing ) on bass impulses, are monitored by a small element and feed back into its internal amps. The result is a very clean and low base performance.

Is there some HAM related stuff involved here??

Yes some, because for receiving FM stereo in good quality you need an outdoors antenna nowadays.
For our 2007 holiday we built a 5el yagi (K6STI design:http://www.ham-radio.com/k6sti/small.htm).
It is now on my roof and serves me well for receiving distant FM radio stations in the range from NNE to South. Its clean pattern and a stone roof on its back does help as it ignores all the local commercial stuff and brings out stations from 150km distance and beyond.
While enjoying the flexibility of a good directional antenna it does have its disadvantages too.
Switching direction to the other favourite station, needs digging out that old rotor control unit and takes ages of time. Now I also have several tuners, which I want to feed as well.

An old VHF vertical was found on a flea market. Its a typical fibreglass version of 1mtr length. Inside I found a small burned ceramic cap. That's also 'typical', as some operators never read the specs.
I tuned this one into a FM radio GP with only 1 radial, made from some brass length.
In my collection of more flea-market stuff I found a small aluminium side mount. Neat !
Last weekend offered lovely sunny weather. I mounted the new omni-vertical to the existing FM antenna setup. Two different coaxes enter my house just at the point where both tuners are located in my shack.





This K6STI type FM radio antenna was made from alum and 40mm PVC pipe. A true home made 1:1 balun is installed to keep the pattern clean. This antenna is easy to build and does a wonderful job.
It was used during our 2007 holiday activities in HB0 .

The new vertical is just parallel to the mast, on the right side.







The vertical was painted black with some 'green spots'.
The radial and mounting bracket were painted too, all just to lower the visual impact.






Does it work?
Yes, the vertical offers my favourite local stations (e.g. Classic Arrow Rock radio) in a range of max 50km. It does not offer the 'FM-DX' like the yagi does. Very, very few stations can be heard and those have S1 and R2-3 only...
But on domestic reception of FM stereo radio stations it performs as expected.

You can never have too many antennas.

.

Receiving Phasing System / Noise Cancelling Controller

DX-Engineering NCC-1

Finally the phasing control box has arrived !
Very surprised to see this unit is 4 times larger than I expected; it measures 24x24x11.5 cm ( or something like a foot x foot x a quarter of a foot, for that matter).
This is the size of a medium HF rig.


Specifications:

• 300 kHz to 30 MHz (Switchable in two ranges; <5-10mhz>5-10 MHz)
• 3rd order output intercept: 32dBm each input, +38dBm both outputs combined
• Available phase rotation >360 degrees (between 500kHz and 15MHz)

Go check their website for the rest

Features:

Or better said, in what respect does this unit differ from its MFJ 1025/1026 counterpart?

• Phase adjustable through more than 360 degrees (MFJ does much less)
• Exceptional dynamic range (30dB more)
• Low noise floor (that is usuallly not much of a problem on the Low-bands)
• Provisions for optional high pass and band pass filters (see pics)
• DC controls with smooth action. Expandable for remote or external control
• Provides power and transmit muting for external active antennas

In a nutshell; after some years this is the natural follow-up of the MFJ.
The MFJ is definitely not bad, but it has some drawbacks in practise. Adjusting both input gain setings and finding the right phase are a bit tricky.
The new NCC-1 has no seperate input gain seetings per channel, but a 'balance pot' instead.
Next it has a switch for swapping the antenna inputs (changing receiving direction on the spot !).

Looking at its internals, especially the transformers, this smells like W8JI design:




Looks like 2N5109's under those heatsinks.


Extra options:

• Provisions for the high pass and/or band filters
• Accessory entry slot for future remote control etc.
  

So?

You can use it for (local) noise cancelling or, produce a steerable 2 element phased vertical RX array.
And there are some more applications.


What will I do with this unit?

First test this unit at a friends location to get a feel how it compares to its MFJ 'predecessor'.

Next I will start building a second 160m reference vertical in my front yard.
This will be >0.10 wavelength away from the backyard version which allows for a very good steerable phased vertical system (sort of very poor mens 4-square). PA3FGA has proven again and again that his double 160m reference phased vertical system works very well, expecially during contesting.

K9AY in my backyard

Picture: K9AY in a field day setup during CQWW-CW-2003

The K9AY has clearly proved to be an ideal backyard lowband receive antenna.
With its small footprint of just 9mtr (30ft) and a height of only 7.5mtr (25ft), it will fit about anywhere. Although this is a directional antenna, its horizontal opening angle in the forward direction is e-x-t-r-e-m-e-l-y wide.
Its merit lies in how well it will attenuate local and medium distance signals from the backside.

Exactly what is the K9AY capable of ?
When switching to one of its four directions, you are focussing on finding the best s/n of the DX by choosing which other direction needs to be attenuated.
So in short; you steer the backside pattern to cancel out the interference.

The K9AY has been in many of our contest and/or fieldday setups. Compared to phased verticals and beverages the K9AY has one big advantage; its high angle front-lobe brings you 'little pistols' in the short to medium distance.

Building the K9AY double loop RX antenna
See ON4UN's Lowband Dx'ing about how to build this simple antenna.
Or visit Gary's website at : http://www.aytechnologies.com/
So far I have build several versions of the K9AY steering box, using different (scrap)parts, transformers etc.
There is nothing critical in the design.
However make sure your vertical TX antenna is at a distance of about 0.3 wavelength.
If not, the pattern might be such distorted that you end up with no F/B.

Grounding
A single ground rod about 1m (3ft) into the ground is ok.

We have successfully used a K9AY setup on a mountaintop 2013mtrs asl (6000ft) during our HB0-dxpeditions. As grounding was not possible at this rocky area, we simply used 4 radials under each horzontal loop. That antenna worked extremely well; even the smallest stations within the European area from 160mtrs up to 20mtrs could be heard on the K9AY. Other local antenna's were dipoles, verticals and two Spiderbeams.


Optimal termination
This can be useful if you have the time to adjust to the optimal F/B on a single situation. But at contesting this is not practical. The standard value per band delivers enough F/B already.

For a fixed direction single loop K9AY setup, I reworked the 4 position steering box to choose from 4 different resistance values. Each are optimized for 160/80/40mtrs and it works very well.


The K9AY in my backyard
Having 2 crossed loops in your backyard, taking up all available space is not feasible. Tripping over the horizontal loop wires is another turn-off, especially when fetching a cold beer from the barn during the dark hours !

During my last Christmas holidays I re-measured the backyard and finally found a single hot spot where I could install the K9AY. I just had to try it; it did only just fit.




The 10m length/50mm dia/5mm wall thickness DJ6NI type fibreglass pole was placed in a large bucket, filled with cement sand. I used the ground connection of my "160m Reference Vertical"which I had temporally removed. The same coax and according heavy common-mode filtering was used.

That is me on the picture. It was pretty cold as you can see some thin snow.

How did the K9AY perform in my backyard?
Directivity was all there; I could easily eliminate some known 160mtr european beacons switching front/back.
But the total "F/B behavior" was not as good as I was used to. Perhaps being so close to the house the pattern wasn't optimal. But then again, almost any antenna out in the field works better.

My biggest concern was the large amount of close-in signals at night. All europeans were MUCH louder compared to the 160m Reference Vertical I was using for so many months now.
Since the vertical has a low-angle "doughnut" radiation pattern, its high angle signals are all attenuated. The K9AY however, does have high angle reception at max gain.
I could hear DX, but the band was constantly filled with strong EU signals :(
I should have realized that up-front.

After 3 days of trying and some further experimenting on fine-tuning the termination etc. I removed the K9AY from my backyard. It did not deliver the improvement I needed.

It is good to have a reference antenna.

Removal of the groud rods (part 2)

And the final one is removed from the lawn at PA3FGA's QTH.
This time a lager hole was tried, not showing any improvement though. It actually made the whole process more difficult.
On the right picture you see Rens and the big lever.


Conclusion:
If you ever decide to install a ground rod, make sure it's final.

K3 add-on

Rens/ PA3FGA just found a great solution for this socket on his K3 :)

I see a DL7KM Double Quad

My colleague just returned from his ski-holidays and handed me these pictures.
I clearly see a DL7KM type "Double Quad" on the lower left side of the mast.

From this distance it is difficult to see for what frequency it is used . One thing is for sure; its polarisation is horizontal.

This is in France in the ski resort "Les menuires". The mast location is called "Pointe de la Masse".

So far I have not been able to find any specific details on this professional (?) application.