Excellent project video from start to the finishing outdoor test. Clear videography closeups and descriptions. You’ve provided an excellent tutorial for building a simple transformer for other devices that may also have severely mismatched, inexpensive antennas. Thank you!
Fantastic idea with construction tricks and beautiful performance demonstration. Congratulation, Paul. Thanks for your efforts. PP1RD- Fernando, from Brasil
Thanks for the DIY Video I just got burnt on one of these radios I ordered a complete Malachite radio case antenna etc. and they sent me an incomplete board charging cable still trying to get my $105.00 back. This antenna project would have been great I built my first radio when I was in the boy scouts in 1966. KD6TXB
A different ham posted a video showing too much noise in the Malachite, and he said adding a transformer wouldn't help the problem. I guess he was wrong. Brilliant video.
You did a great video showing simply how to make one yourself. Incredible how many hams today aren't willing to attempt for themselves such a simple project, as evident in this comment section. Thank you.
These are also a "must have" if you want to just clip a 20 ft wire to the whip antenna and string it across a room or toss it out a window. Or if you erect a simple longwire outdoor antenna you put one of these at the coax feedpoint. I already have a couple of these laying around but they are set up for BNC because that's what the Softrock and others homebrew units use. I also have some simple high pass, low pass and bandpass filters I'm going to convert to SMA. They can really help with these types of radios with their wide band front ends especially with wideband non-resonant antennas like a simple longwires
If I wanted to buy a professional made antenna that already did this, what would it be called? I love the DIY, but it might be best to buy a manufactured version.
Very much enjoyed the drill method to twist the wires for the transformer. That alone was worth the price of admission here. One note; for "windings", the English version would pronounce it "wine-dings" (or the non-alcohol version: "whine-dings"), versus "wing-dings", otherwise, your English is great. Excellent work, Paul...as usual! 73! de WX0V
@@OM0ET The other great thing about this video, instead of just complaining about the whip antenna (as others on You Tube have), you dug into WHY it was not working, and came up with a solution. Another reason why this is my favorite You Tube channel. Superb, Paul...just superb. 73! de WX0V
Hello Paul. I'm wondering why signal is better on antenna with your transformer... I mean as short antenna as 100-150cm has impedance of unity ohms on 40m band and lower on lower bands. You made transformer which usually is used to transform Hi-Z (2500ohm) end-fed half wave dipole to 50 ohms. In your example you transform 0.5ohm antenna (150cm short ground plane for 7MHz) in addition divided by 49! You got final impendance ->> 0.01 ohm
Hello both! It is an interesting technical discussion. I think the problem is the complex impedance in this case. Short antennas have a low resistive component but a huge reactive component. Paul probably considered only the absolute value of such impedance in this case. What is your opinion? 73! Michal OK1GHZ
Would it be possible to install the transformer inside the case of the receiver with some kind of selection switch so that it is possible to chose between the direct connection and the transformer or would a switch cause loses in the signal?
The reason for 49:1 is a longwire antenna generally as a rule of thumb has an impedance of 2450 ohms which is 49 times the 50 ohm input of a receiver. Unlike most portable shortwave receivers which already have a high impedance input you need to have some matching on these designed by amateur radio operator type receivers that have 50 ohm inputs to make a whip or random wire type antenna work. When connect put a high impedance antenna to a low impedance input you end up shunting most of the signal to ground much like a resistor voltage divider (Yes that's very simplified but for practical understanding it's essentially true for receive only applications)
Hi! Nice video, I build It for my portable SDR setup, It improved the reception. Would you mind a question? Some images of 49:1 balun show a optional 100pc ceramic capacitor between ground and antenna connection of the receiver part. Is this really needed? 73s de PU5TOS.
Thank you Paul for this build video, I am building two versions so I can see if they are both wound correctly which I think is the most difficult to reproduce , can you please advise on which Malahite setting to use with your Transformer, Hi- z or 50 ohm please many thanks again.
@@OM0ET If you do, it would be nice to design it in such a way, that it also works as a strain relief . Otherwise is everything too heavy for the original, board soldered SMA.
PLEASE I NEDD ONE OF THOSE TRANSFORMERS.... !!!!!!!! There's a Huge difference in gain. Thanks for the video my friend, very helpful and interesting. 73s from KJ4BGW
I discovered a gap (Out of range) at the military band. 262.6250 MHz (Dutch AOCS NM QRA primary). Is it true this receiver has gaps and frequencies that cannot be set? I have a full band receiver exactly like yours but (-Rev Espe).
There used to be made an antenna called Miracle Whip that was adjustable and on Ebay is one now made in China, do you think it might work for that unit?
If it’s the same miracle whip as the original, probably will work. Inside the miracle whip unit there’s a toroid with multitaps on it. By adjusting the rotary adjuster you select a different tap. At VHF/UHF the toroid is effectively removed and the antenna length is adjusted for best results.
Thank you for this project. I tried using this on a tinySA spectrum analyzer to see if it would improve the reception at 300 MHz. I actually got a reduction in the signal. Is there a reason why it wouldn't work on the tinySa?
Ebay has all kinds of connectors, search for "SMA male solder" and "F connector female solder" and you should find them easy. Dont buy the other kind of SMA connector.. the RP-SMA.. i did buy some cables with that format once lol :) I dont know what RP-SMA is for but they did not fit the SDRplay :) But good there is SMA to RP-SMA converters to buy so i can get some use for the cables. I just bought the cheapest cables searching for SMA and found out that way that there was something called RP-SMA too :) To build a docking station box with antenna mount and the transformer inbuilt in the box and a screw-on SMA cable to the antenna could be a good way to get strain relief on this handheld Malachite SDR i guess and could perhaps make it more comfortable to hold a larger box too :) But perhaps not as small to put in the pocket... hmm :)
Hello from YO5OUY. Perdona si escribo en Español,se hablar mejor spanish como en Ingles! Muchas gracias,muy educativo y divertido en el mismo tiempo,me gusta tus explicaciones y tu gran paciencia, gracias para tus trabajos! Lástima para tus arañas de tus manos ! "Setenta y tres!" Thanks and 73!
Hi, I was wondering if you sell these, or know of a similar design that is for sale? Unfortunately I am not good at DIY crafts and wish to buy something that works out of the box so to speak.
Original Malachite has filters on short waves, adjustable attenuator and "high Impedance" mode when you selecting Telescopic antenna by menu. Clone is clone. Not all functions are added.
that may be so, but the russians havent taken the western market serious yet. I would always prefer russian tech over chinese tech, but the russians dont seem to care too much about non-slavic customers. So far...
@@zoolkhan Russian Malachite is made by hands. They do not have robotic lines as china do. I have ordered one. (price near 140eur) But they are making it two month. After half a year I will have it!!!
I can't figure out where the idea of twisting the wires will increase coupling. Coupling occurs because the flux in the toroid is common to both coils which provides the coupling.
Thank you for this vid. Is it worth buying this receiver? I’m a shortwave DX listener, I own a PL660 and I reckon it has a good performance, but I’d like to have a more compact receiver. 73’s.
Question the socket for headphone which I have a Attachment to my computer will that work on my PSK 31 software secondly I orders a 25m long wire HF with BNC I have a attachment for the BNC will this work Look forward to hearing from you paul In Kent
Q: "socket for headphone which I have..." sorry I don't know to answer to this question. Q: "I orders a 25m long wire HF with BNC..." yes, all antennas with impedance near 50ohms will work with this receiver.
Great video as always! On my Malahit FW 1.10a I have a High Z/50 ohm impedance option. I think ? that does the same thing. Was that option not available when you did this video? I also happen to have a Miracle Antenna with a small onboard tuner that gives me similar results. Hope this helps. ve3bwp
2m is useless as inteferance from the internal circuit, but its great on HF exept for powerfull stations swamping the band , half of the memory slots do not work. The freq steps are a REAL pain on the touch screen to touch correctly and selecting a station from the touch screen is bad as you end up with tiny frequency steps to correct as frequency step changes., once on a station it is pleasing.The sound is really full and detailed on FM and great on hf. I On mine the Pre amp setting is wrong ie off is ON, and on is OFF, leave it activated ie OFF on the rod antenna and dont activate it on a 20m wire or similiar. Setup I find 75db on AGC as recomended by the Russian designer "George". RF gain 20 to 25 on rod with activated preamp, 10-15 setting on 20m wire with preamp not activated (with 9:1 balun).The screen was not flush with the case a gap of about 3mil at one edge, I opened the front and found the edge of the circuit board snapped of at 2 corners,thats why it would not hold down. If you open the case it will be a pain as the other side of the visible case screws is a nut which will drop off inside! It is an incomplete radio, but it receives way better than my techsun 660 and sounds better and picks up more than my Icom pro due in part to having no mains borne inteferance which renders my HF radios useless at times thats what was apparent straight away on battery power. Some time it does not want to come out of hard setting and a restart is required. No speaker grill is not a good idea, its been thrown together, not Chinas best offering, shame.
Even clone Malachite receivers with full Russian software are showing a button (under HARD), where you can select between Hi-Imp input and 50 Ohms input. How does this comply with your external device ?
Hello all, I have built this, using the Toroid from Mauser (as per one of the comments below), the recommended wire etc. - and it does not work at all. The signal is the same (or maybe a bit weaker) vs. when I just use the telescopic antenna on my Malachite radio. I must have messed something up - but what is it? I followed the video to the letter - and I have built two of these transformers: both do not seem to work. Thank you for any ideas! (My test was on AM radio broadcast)
You might have the wrong type of toroid material. Some are optimized for under 1MHz and do not work at all well on shortwave. Also kinda obvious but you need to use INSULATED wire. The video shows a copper wire with clear insulation which might lead you to think that plain old dorbell wire, stripped, will work. It won't!
Great demonstration! Have you tried with some other toroid type, for example type 2 (red) type 6 (yellow) or those cheap green ones? 43's are really hard to find.
Excellent project video from start to the finishing outdoor test. Clear videography closeups and descriptions. You’ve provided an excellent tutorial for building a simple transformer for other devices that may also have severely mismatched, inexpensive antennas. Thank you!
Thank you so much for very kind comment! :)
It's a pity that it is not for sale commercially because it is nice and small
I love small things that are so simple but have a very big effect.
That was a very good thought, Paul!
Thank you and 73
Bernd
You should build and sell those impedance adapters, surely lots of SDR users like me, will buy it.
Brilliant Idea ,matching the impedence.And the nice construction ..Thamks Paul..
Wow, Paul this is very impressive improvement. Excellent work! Thank you very much for the information!
Thanks Paul great video. We forget how important impedance matching is when just receiving. Your video production is great, easy to follow .... Thanks
Thank you so much for watching and nice comment! 🙂
Just finished to build it! What a improvement! Thanks for sharing it. 73 de PT2JR.
Fantastic idea with construction tricks and beautiful performance demonstration.
Congratulation, Paul. Thanks for your efforts.
PP1RD- Fernando, from
Brasil
Thank you Fernando 😉👍
Thank you Paul for this very informative video, I am going to build this right away.
Thanks for the DIY Video I just got burnt on one of these radios I ordered a complete Malachite radio case antenna etc. and they sent me an incomplete board charging cable still trying to get my $105.00 back. This antenna project would have been great I built my first radio when I was in the boy scouts in 1966. KD6TXB
Sounds Like You Got Scammed Bad :(
Nice !!!!!! Great idea Paul !! I will be doing the same antenna enhancement on my home made portable DSP receiver.
Well done PAUL and the 49/1 and the 64/1 are my favorite UNUN, they just seem to always work. 73. KV5P
Nice to see someone that can solder Nice project Thanks
For anyone that doesn't want to build their own unun, there's one you can buy that works very well called "Magic Whip" available from Greece on Ebay.
A different ham posted a video showing too much noise in the Malachite, and he said adding a transformer wouldn't help the problem. I guess he was wrong. Brilliant video.
Wow. Nice work. Great video again Paul - cheers!
1 of my favourite 49.1 great video.
You did a great video showing simply how to make one yourself. Incredible how many hams today aren't willing to attempt for themselves such a simple project, as evident in this comment section. Thank you.
I didn't a multitude of projects on your channel kemosabi.
These are also a "must have" if you want to just clip a 20 ft wire to the whip antenna and string it across a room or toss it out a window. Or if you erect a simple longwire outdoor antenna you put one of these at the coax feedpoint. I already have a couple of these laying around but they are set up for BNC because that's what the Softrock and others homebrew units use. I also have some simple high pass, low pass and bandpass filters I'm going to convert to SMA. They can really help with these types of radios with their wide band front ends especially with wideband non-resonant antennas like a simple longwires
Brilliant! Thanks for this. Excellent video. I'm waiting for my Malakit to arrive but it could be useful for my RSPdx de M0SNR
If I wanted to buy a professional made antenna that already did this, what would it be called? I love the DIY, but it might be best to buy a manufactured version.
Thanks for sharing your technical skills , concerning this unit!! Fantastic presentation on antenna mod!!
Thank you so much! :)
Outstanding Paul.....I wish a pre-made version (I'm not very handy with such gear) was available. 73s
Thank you so much. Now I know how improve the reception when mine arrives!
Well done, very practical improvement.... 👍🏼
Great video, I am new to SDRs and your video was great to make a better mobile antenna. Thanks for posting it.
Very good demonstration. Good language skills. 73 and happy trails to you. Thank you. JR
Thank you so much!
Nice video. Perfect description
You did not show the settings of the receiver. Was it set to 50 ohms or hiZ?
it doesn't matter what settings are set, because in clones without additional board will never work ;) it's for original Malachite only.
Brilliant! Now I have to get one of those radios.
Good tip and build Paul 👌
👍👏👏
Very interesting, big difference!👍
This is brilliant and easy to build. :0)
Thanks for the valuable information!
Very much enjoyed the drill method to twist the wires for the transformer. That alone was worth the price of admission here. One note; for "windings", the English version would pronounce it "wine-dings" (or the non-alcohol version: "whine-dings"), versus "wing-dings", otherwise, your English is great. Excellent work, Paul...as usual! 73! de WX0V
Thank you Scott for advise :) I am just a self learner so it helps me to learn that way ;) hihi 73 and thanks for watching as usual :D
@@OM0ET The other great thing about this video, instead of just complaining about the whip antenna (as others on You Tube have), you dug into WHY it was not working, and came up with a solution. Another reason why this is my favorite You Tube channel. Superb, Paul...just superb. 73! de WX0V
Hello Paul. I'm wondering why signal is better on antenna with your transformer... I mean as short antenna as 100-150cm has impedance of unity ohms on 40m band and lower on lower bands. You made transformer which usually is used to transform Hi-Z (2500ohm) end-fed half wave dipole to 50 ohms. In your example you transform 0.5ohm antenna (150cm short ground plane for 7MHz) in addition divided by 49! You got final impendance ->> 0.01 ohm
I measured impedance of this telescopic whip. On 160m = 5000ohms, 80m 2450ohms atc. higher frq, lower Z
@@OM0ET So looks like antenna is not simple whip connected to hot pin. It has some matching circuit itself. Interesting...
@@lucjann.577 no, i measured it straight trough the reductions
Could you try it the same with simple wire with the same lenght? It's very strange for me
Hello both! It is an interesting technical discussion. I think the problem is the complex impedance in this case. Short antennas have a low resistive component but a huge reactive component. Paul probably considered only the absolute value of such impedance in this case. What is your opinion? 73! Michal OK1GHZ
Would it be possible to install the transformer inside the case of the receiver with some kind of selection switch so that it is possible to chose between the direct connection and the transformer or would a switch cause loses in the signal?
There is a requirement when using a short whip on frequencies below 20Mhz to impedance match the low
I prefer passive solutions over active solutions
The reason for 49:1 is a longwire antenna generally as a rule of thumb has an impedance of 2450 ohms which is 49 times the 50 ohm input of a receiver. Unlike most portable shortwave receivers which already have a high impedance input you need to have some matching on these designed by amateur radio operator type receivers that have 50 ohm inputs to make a whip or random wire type antenna work. When connect put a high impedance antenna to a low impedance input you end up shunting most of the signal to ground much like a resistor voltage divider (Yes that's very simplified but for practical understanding it's essentially true for receive only applications)
Really interesting video, very demonstrative. Thank you!
Always perfect Paul 😜👍📡
Genius, thank you.
Hi! Nice video, I build It for my portable SDR setup, It improved the reception. Would you mind a question? Some images of 49:1 balun show a optional 100pc ceramic capacitor between ground and antenna connection of the receiver part. Is this really needed? 73s de PU5TOS.
It mainly used for better performance on a higher bands, especially for TX
Thank you Paul for this build video, I am building two versions so I can see if they are both wound correctly which I think is the most difficult to reproduce , can you please advise on which Malahite setting to use with your Transformer, Hi- z or 50 ohm please many thanks again.
The Hi-Z and 50ohm features doesn't work on chinese clones. That's why I made this transformer ;)
@@OM0ET Thank you Paul.
What is the purpose of twisting the wire together for two turns?
finally someone with some common sense
Very informative video, thank you for shearing.
Thank you very much!
I am very interested how you calculate or measured to come to the result of the toroid size and windings.
here for example, but smaller version: elginradio.wordpress.com/2017/10/17/end-fed-half-wave-antennas/
Can transformer be mounted inside radio and add second antenna jack for it?
Actually yes, but this jack will be useful for shortwaves only.
Please put these for sale on your website! PLEASE!
Yes please.
hmm I have to think about it ;)
@@OM0ET Cover it with some thick heat shrink and you've got a product. And please put a BNC or SMA on top and not an type F connector.
@@OM0ET If you do, it would be nice to design it in such a way, that it also works as a strain relief . Otherwise is everything too heavy for the original, board soldered SMA.
Parts are available here:
www.mouser.com
623-5943000301
5943000301
43 Toroid
$0.29
RoHS1538-73251-3130
73251-3130
SMA RA PCB RECPT
$6.14
RoHS2523-132135
132135
SMA R/A PCB PLUg
$11.02
Paul, did you happen to check the frequency response of your little transformer? I wonder which bands we can expect it to work the best on?
PLEASE I NEDD ONE OF THOSE TRANSFORMERS.... !!!!!!!! There's a Huge difference in gain. Thanks for the video my friend, very helpful and interesting. 73s from KJ4BGW
question is there available in the market telescopic antena with buikt in transformer. thank you and stay safe all.
Love the "grin ding" of the "win ding" ;)
OK, then let's you try to say correctly "srdiečko" 😉👍
@@OM0ET He obviously didn't have the heart to even try! ♥ ☺️
"Serdietchko!" 😉
@@michaelfuchs1467 😃 yes, exactly!
I discovered a gap (Out of range) at the military band. 262.6250 MHz (Dutch AOCS NM QRA primary). Is it true this receiver has gaps and frequencies that cannot be set? I have a full band receiver exactly like yours but (-Rev Espe).
nice transformer it works ! well done !
So they put wrong antenna?
Very interesting. On mine if I press Hard then the Attn button it goes from Hi Z to 50ohms. Cheers from George
Excellent 👌 I was planning to buy this RADIO.
very good project, what is the inductance of the inductor you have built?
There used to be made an antenna called Miracle Whip that was adjustable and on Ebay is one now made in China, do you think it might work for that unit?
Hard to say, I never tryed that antenna :)
If it’s the same miracle whip as the original, probably will work. Inside the miracle whip unit there’s a toroid with multitaps on it. By adjusting the rotary adjuster you select a different tap. At VHF/UHF the toroid is effectively removed and the antenna length is adjusted for best results.
Do you sell these either as a kit or preassembled?
Thank you for this project. I tried using this on a tinySA spectrum analyzer to see if it would improve the reception at 300 MHz. I actually got a reduction in the signal. Is there a reason why it wouldn't work on the tinySa?
WHERE CAN YOU FIND THE ANTENA CONNECTORS AS SHOWN IN THE VIDEO.....the two connectors soldered to the PC Board ????
Ebay has all kinds of connectors, search for "SMA male solder" and "F connector female solder" and you should find them easy.
Dont buy the other kind of SMA connector.. the RP-SMA.. i did buy some cables with that format once lol :) I dont know what RP-SMA is for but they did not fit the SDRplay :)
But good there is SMA to RP-SMA converters to buy so i can get some use for the cables. I just bought the cheapest cables searching for SMA and found out that way that there was something called RP-SMA too :)
To build a docking station box with antenna mount and the transformer inbuilt in the box and a screw-on SMA cable to the antenna could be a good way to get strain relief on this handheld Malachite SDR i guess and could perhaps make it more comfortable to hold a larger box too :) But perhaps not as small to put in the pocket... hmm :)
Hello from YO5OUY.
Perdona si escribo en Español,se hablar mejor spanish como en Ingles!
Muchas gracias,muy educativo y divertido en el mismo tiempo,me gusta tus explicaciones y tu gran paciencia, gracias para tus trabajos!
Lástima para tus arañas de tus manos !
"Setenta y tres!"
Thanks and 73!
Is there an antenna similar to this custom one that's already pre-build for the Malahit?
自藕阻抗变换及双绕成电容式？
可否用电视300Ω/75Ω
天线匹配器改绕成这非平衡式？
你设计的小巧！👍！
Is there another option to just buy the correct antenna? If so which one? Thanks for the interesting video.
The original Harris tape style HT antennas have a small unun under their rubber base as well.
Not so sure about the knock-offs.
Hi, I was wondering if you sell these, or know of a similar design that is for sale? Unfortunately I am not good at DIY crafts and wish to buy something that works out of the box so to speak.
I think that the HIGH -Z function in the menu is there to take care of this problem.
Yes, but this feature work only with aditional board for original Malachites. There is no space for such a board in this chinese clones.
Don't the clones have a thicker case?
Hello would FPV RC rx aerials be useful for eg clover leaf and shotgun?
Pure genius. Will build one for my malachite sdr radio
where did you source the pcb board
Original Malachite has filters on short waves, adjustable attenuator and "high Impedance" mode when you selecting Telescopic antenna by menu. Clone is clone. Not all functions are added.
that may be so, but the russians havent taken the western market serious yet. I would always prefer russian tech over chinese tech, but the russians dont seem to care too much about non-slavic customers. So far...
@@zoolkhan Russian Malachite is made by hands. They do not have robotic lines as china do. I have ordered one. (price near 140eur) But they are making it two month. After half a year I will have it!!!
I can't figure out where the idea of twisting the wires will increase coupling. Coupling occurs because the flux in the toroid is common to both coils which provides the coupling.
elginradio.wordpress.com/2017/10/17/end-fed-half-wave-antennas/
Thank you for this vid. Is it worth buying this receiver? I’m a shortwave DX listener, I own a PL660 and I reckon it has a good performance, but I’d like to have a more compact receiver. 73’s.
Me too! PL600 and Sony ICF-SW7600G.. do these type of RXs also have a 50ohm front-end? anyone knows?
Question the socket for headphone which I have a Attachment to my computer will that work on my PSK 31 software secondly I orders a 25m long wire HF with BNC I have a attachment for the BNC will this work
Look forward to hearing from you paul
In Kent
Q: "socket for headphone which I have..." sorry I don't know to answer to this question. Q: "I orders a 25m long wire HF with BNC..." yes, all antennas with impedance near 50ohms will work with this receiver.
Can these tiny SDR receivers actually get good dx stations like Short- wave?
Of course yes 👍
Why not enable the preamp on the radio?
Great video as always! On my Malahit FW 1.10a I have a High Z/50 ohm impedance option. I think ? that does the same thing. Was that option not available when you did this video? I also happen to have a Miracle Antenna with a small onboard tuner that gives me similar results. Hope this helps. ve3bwp
He has a clone and that option works only in original Malahit (you hear "click" of a relay inside when hi-z enabled/disabled). In clones its useless..
Great Video
Why did you use a twisted pair of wires for the low impedance winding?
elginradio.wordpress.com/2017/10/17/end-fed-half-wave-antennas/
OM Paul can you provide URL for this clone? It is attractive!
Sure, the link is in video description of this video here: ua-cam.com/video/7oduM0ISWRI/v-deo.html
Any chance could make one of these and make it sale?
Question, would it be affected it, if you put wax on the loops you made on the ferrite ring to hold the loops in place?
No, it shouldn't be the problem. I did it with melting glue and covered heatshrink. All works fine.
@@OM0ET thanks forgot about a glue gun, saves me using a candle 😆
@@GhostCallparanormal 😄👍
why a 49:1 transformer when your malachite receiver has a hight impedance setting antenna,when you use the whip antenna 75 cm long ???
This clone hasn't hi-Z circuit built-in
@@OM0ET ok
2m is useless as inteferance from the internal circuit, but its great on HF exept for powerfull stations swamping the band , half of the memory slots do not work. The freq steps are a REAL pain on the touch screen to touch correctly and selecting a station from the touch screen is bad as you end up with tiny frequency steps to correct as frequency step changes., once on a station it is pleasing.The sound is really full and detailed on FM and great on hf. I On mine the Pre amp setting is wrong ie off is ON, and on is OFF, leave it activated ie OFF on the rod antenna and dont activate it on a 20m wire or similiar. Setup I find 75db on AGC as recomended by the Russian designer "George". RF gain 20 to 25 on rod with activated preamp, 10-15 setting on 20m wire with preamp not activated (with 9:1 balun).The screen was not flush with the case a gap of about 3mil at one edge, I opened the front and found the edge of the circuit board snapped of at 2 corners,thats why it would not hold down. If you open the case it will be a pain as the other side of the visible case screws is a nut which will drop off inside! It is an incomplete radio, but it receives way better than my techsun 660 and sounds better and picks up more than my Icom pro due in part to having no mains borne inteferance which renders my HF radios useless at times thats what was apparent straight away on battery power. Some time it does not want to come out of hard setting and a restart is required. No speaker grill is not a good idea, its been thrown together, not Chinas best offering, shame.
Still using the TEST firmware?
Very good. Congratulation 👍👍
Even clone Malachite receivers with full Russian software are showing a button (under HARD), where you can select between Hi-Imp input and 50 Ohms input.
How does this comply with your external device ?
clones don't have an additional boards, this feature do not work
Did you try to change antenna input impedance from 50 Ohms to Hi Z in the HARD firmware option?
Chinese copies doesn't include required hardware
Hi Paul I am registered blind but I would like to have that type of antenna is it possible for you to make me one would be much appreciated
What surpose for this you can hear them
But they can't hear you
What torroid did you use?
Hello gibt es in Deutschland zu kaufen.can the device be bought in Germany or where?
Did you buy the PCB as-is, or did you make it?
I did this PCB :)
That’s great!
Can you buy this some were. if so were can i get one.
Hello all, I have built this, using the Toroid from Mauser (as per one of the comments below), the recommended wire etc. - and it does not work at all. The signal is the same (or maybe a bit weaker) vs. when I just use the telescopic antenna on my Malachite radio. I must have messed something up - but what is it? I followed the video to the letter - and I have built two of these transformers: both do not seem to work. Thank you for any ideas! (My test was on AM radio broadcast)
You might have the wrong type of toroid material. Some are optimized for under 1MHz and do not work at all well on shortwave.
Also kinda obvious but you need to use INSULATED wire. The video shows a copper wire with clear insulation which might lead you to think that plain old dorbell wire, stripped, will work. It won't!
Great demonstration! Have you tried with some other toroid type, for example type 2 (red) type 6 (yellow) or those cheap green ones? 43's are really hard to find.
No, I did with toroids I had currently on stock :)
great job..