Friday, February 25, 2022

The new loop experiment

 Much long after designing an experimenting with wire antennas i decided to experiment with a Moebius antenna  design similar to the the home made youloop design as shown in the swling page 

Instead of the R58  types of cable I used RG6  the standard cable used for TV and satellite antenna lead that was very  handful together with some wire benders zip ties and cable terminals I used also the soldering probe and solder for any required joints but proved unnecessary as  the zip tie was quite tight over the cabe for all the time i was experimenting

d

I made a mini change in the design :  I cut the cable in the middle, changed the poles in the middle of the wire while for the remain end i turned the cable so that the middle core could be in parallel and connected with a terminal block

 

and here is on how the mid points were connected:  It was much easier to jeep that quite safe and steady instead to use the solder. Its more than 15 years since i stopped using solder for making some basic electrical engineering . I also know a few technicians nearby my house who stopped soldering as most work  is just plug and play with mother boards!

 


this si the inversion part ..

Together with  joining the antenna parts I added a 'cloth hanger' . an idea seen in a antenna building This retains the shape of the cable.  Face-group Some short self bent wire tights the cable  soflty over the hanger


For more experimenting i used two different  lead cables to connect in the SDR or in the radio:
- a twin wire as used for electricity connections of 0.75 m2
-a 1.5  meter RG6 cable as in the photo 

The results were poor : Using the PL330 radio seen no  significant change in terms of noise caneling as far as i tested.


Putting the antenna over the railings (ie the metallic fence) raised the SNR to more than 10 db  Seen also a minimal level noise deletion as the antenna was turned


Testing with the spectrum analyzer as above shows many ghost carriers across the bands As you can see there are some relatively strong signals in the lower two bands there is also a huge noise level 


Instead of the band to be in the clear the SDR shown highly numerous unwanted carriers .someone called that close proximity but i think that most of them are unwanted spurs coming from the SDR or PC

step 2 

Something was  wrong for sure . Testing once again all connections i understood that the cables shields ends were  not connected each other . I removed  the plastic cover of shield ends by 1.5 cm and again used a new zip tie to keep them connected


the shielded part is shown in black


Results were quite better in terns of noise canceling. Signals were again the same with better reception above the railings but the spurious signals insisted  to exist 

step3


Finally days after , I have found a  toroid that is around 1,5 cm in diameter.This is the only available in the city. the balun designed was 1:1 using appliance twin cable . This was my fist time making a balun. Really a relatively easy job!

Again the problem with  the unwanted carriers existed  in  the SDR.  Tested not only with the RSP1a but also with the Aisrpy Discovery which made both SDR and program getting mad from the unwanted carriers


I was strikingly disappointed and dismantled the antenna and  immediately ordered the Youloop from RTLSDR blog via ebay ata cost of 40Eu . I was quite hurried to end these tests with this antenna but no sellers in Europe have been found in ebay or any other platform  for faster delivery


In the mean time :this is the  spectrum analysis of the 10 m antenna when is connected via the cable to BNC connector to the SDR (any SDR )

hmm it was a mistake: the  antenna wire was connected in the ground wire if he wire to BNC adaptor. the fault ws made by the person who soldered all the ends and connected the ground wire on the positive

 


By using connecting the ground cable in the BNC adaptor it adds many spurious . if using the ground to the the SDR case the curve is quite different and reduces the noise level! 


This is what happens when using a VHF whip , in the HF bands ...

update : the original antenna  has been received much earlier than i could expect that is in just two weeks . the report is the next in my blog and works very well

https://zachs-radiopage.blogspot.com/2022/03/short-review-for-youloop-antenna.html

update2: I m also expecting a clone model for test for testing their boxes that seems bigger and possible harder than their youloop counterparts at least by view This is 10 euros cheaper than the youloop



Difference between Airpsy and RSP1a

The time i tested the loop antenna  i was also listening with the standard existing 10 m antenna was was above the balcony fence

Below are two screenshots with my two SDRs . To which receiver you think these  screenshots correspond?

(A) receiver

 
(B) receiver
 

 
 

Friday, February 4, 2022

DX Ideas for 2022

..... after reading an article a email based DX forum  under the title
'What is/are your personal DX'ing challenge(s) for 2022?'
i posted a  minimal text in the email group hat was the v1 This is the v2 with some more analysis


For MW /SW ( I m mostly a SW listener )
Try to listen to some hard to listen stations as possible .As I know most stations on the band  I prefer also to listen  via remote SDRs in Europe and the SEA. Sounth east asia  is my main music  interest very long ago with interest in Thai Malay Indo and Taiwan. I  prefer  older Chinese pops before 90s whid for the remain three countries my interest is since the 80s and then
My holy grail on MW  is listening to Lyca Radio on 1458 , In my area in Thessaloniki the signal is very low ,even if checked  with the Tescun mini loop or the invert 16 m antenna. It is too bad that the remain country can receive it much better . See also below 


Listening to Greek pirate radio stations on MW is ranked 3-4  in my intereest  Many times I call them for some mini report via telephone The most interesting station is a 'friends’  CQAM  transmitter  that airs music in much better ‘quality’  than the local FM!
Many times i report in a related Facebook group with SDR screenshots from my RSP1a or the PL330

Semi-pirate or pirate  radio from Europe on SW is a different question The last two years was my only source of QSLs

There was a poor interest of enhancing  my basketenna. It is a  55x35 cm a former vegie plastic frame that was used 10 yeas ago and then stopped to use it abruptly after 2019. The idea  was simply  to tripled the turns so that the antenna can tune also on LW. As a MW Loop  it has more than 25 db higher signal than the Tecsun antenna. Its a design by a ham radio fan.

Living in Litohoron nearby the mountain Olympus (the  Gods home per Greek mythology)   the MW situation is much  better  but I have to be outdoors. I many times do my jogging and take my PL330 in a nearby jogging/spazieren  alley where many people do the same as I. I keep this radio  at hands while use mini  earbuds  to listen to several favorites radio stions in shortwaves while walking One of them is the infamous CNR13 /Xinjiang with funny program on 12-14 at includes music At 15 there is a Chinese subprogram. tested once Lyca with very good signal while on 17z and after and also Sawa from Djibuti. 

Instead of older times around  the 2000 period when there was  no noise inside the city, the last 3-4  years were very different even outside the city. In a power outage in the end of January 22  and using a installed 32 m wire fir shortwaves , reception was still noisy even if there is no electricity.  readout indicator shown a 30/00 signal form unknown noise that is possibly from the nearby mobile telecoms tower.  Its distance is around 100 m long. This noise was tested also in a few more points far from the village


For FM – using Tecsun PL radios is as like DXing .  its bandwidth is very narrow
The aim is only one: to update the FM listing in both areas  : Thessaloniki and Mount Olymp There are standard cases to listen several to stations from the Skopje borders (we in N.Grece or Macedonia call the country as Skopje,  you others call them N Macedonia) and also Blagoevgrad Bulgaria.  

My aim for this year is to test a few more antennas  starting with a home made Youloop , first without balun. Finding these accessories is quite difficult in this city 

 

Unrelated: last year i have ordered a few things from China via ebay with a total cost of around 15 Eu. the local post was quite slow to deliver the things:the
The first parcel was posted on Oct18 and delivered in around 120  days
The second parcel delivered via Athens then stopped updating the system and finally was  received after 110 days
The third parcel has been ...landed to the local distribution service on Jan 8. After that the parcel is possibly lost or stolen.



 






Wednesday, February 2, 2022

The Xmission storiof R Cairo on 1/2/2022

It was really a very fascinating day on 1/2 when Cairo was the most time transmitting on shortwaves. Together with that i had part of their complete listing of their transmission schedule for checking

Cairo at 1520 was with open carrier but nearly before the 1530 with music then BoH (exact +30) pips hymn then talks A sper list the program was in Albanian Signal 43/10 in my PL330 with 10+3 m external antenna wire Nothing on 1715 on both radio and local SDR  Their frequency is 9440 with programs in Albanian and Turkish respectively I was using only my PL330 radio that time listening the station. 

Audio in QAM mode  is here  
Also this also on QAM can show on how distorted audio ca be heard
Its  beter to hear that with headphones! 

 
this is screenshot from the transmission on 3/2 as noticed below this is th silent transmiter


 
The next program is in 1800-1900 with program in Italian  Here is part of the screenshot with their waterfall on 1842 .Please click on the picture to see the  picture in full in a new tab. it ea slao interesting that even with this string disortion

This is the centered signal in the waterfall . As you can see   the tace is totay different die to these main features:
-distorted signal ,,seemingly overmodulated
-FM ish like, but not  exactly signal Changing the decoder to NFM there is nearly nothing heard except a very poor hum  


It is also worth to show that this signal can also cause wide band splatter It is shown wit the quite wide lines in the spectrum. the  range can be more than +/-50 kHz as per the photo


 
Here is the full picture that shows all my necessary receiving information. waterfall plus signal hitory or better to call  fading graphic The signal has quite deep fading that is of the 30+db  for 10 minutes of tracing. i can suppose this is some propagation effects than fading . Standard multi path can be shown in very sort timed intervals of around 1-10 seconds from my practical experience 
 
From my log : 

9900 Cairo again 1839  in Italian quite distorted but quite comprehensible if headphones are used. I ALWAYS listen with ear- or headphones. Using a BLON03 for tthat time  if you know that.   55/20 in my PL330 and -57dbm in the nearby SDR

 
 
 
In less than 30 seconds before 1900 they seem to switch off and QSY  to 9510 for the next transmission that follows exactly to their schedule with program in German. you can see that in the  left side of the window above
 

There is another carrier on 9510 with program in Russian om the same time  with buzz and low modulation  with 52/24in the PL330 It is heard much better than the other frequency after you pump up the volume . System marked as under the thick line above   


At 2000 Cairo changed to 9885 with program in French and the
buzzing carrier with rather no audio up to S9+20 -57 dbm 

 

 


 

9900 at 2115 carrier with poor mod and disturbed, supposed in Portuguese  per listing. Poor in Hungary is good on Carlow Eire as checked - didn't make any screenshot 

After 2150  Cairo left the frequency with no more transmissions as checked in the band leaving only echoed CNR in the frequency  ,that is a double  CNR jammer against RFA 

----

ON 2.2 Cairo was active  till 1905 using the low modulated transmitter on 9900.





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