Category: SAR32M

SAR32M – Portable antenna from Greece

By 25 July 2021 Antennas, Malahit DSP2, SAR32M 4 Comments

The radio amateur SV2CZF makes some very interesting antennas and sells them on his website for a small fee: https://www.sv2czf.com

For a long time I had been tempted by the MWA30 (https://www.sv2czf.com/mwa30.html), which is a very small portable mini-whip that runs on battery power. Unfortunately, mini-whips must be well grounded, so I decided to use his latest antenna, the SAR32M. This one works even without good grounding and you can connect an antenna via a whip antenna like a telescopic or a loop.

Features

  • Reception from 50 KHz to 175 MHz
  • Built-in rechargeable battery which can be charged via Micro USB port (approx. 10 hours battery power)
  • A normal whip antenna, like a telescopic antenna, can be connected
  • A loop can be connected
  • A loop and a telescopic antenna can be connected in parallel
  • Impedance adjustment for shortwave
  • Built-in Pre Amp for amplification
  • Only suitable for receiving, when transmitting the SAR32M will be damaged directly

How to order

The SARM32M is already shown on the homepage, but cannot be ordered through it yet.

  • Write a e mail in english to this adress: info@sv2czf.com
  • By default, the SARM32M is delivered with BNC connectors. But you can also ask SV2CZF to install SMA connectors
  • Antenna 94,99 € and shipping 6,99 €. The antenna is shipped in a bubble envelope and passed customs without any problems for me
  • The shipping took for me from Greece to Germany only 5 days.

Experience in practice

I use the SAR32M mainly with my Malahit DSP2. Here, the SMA32M with the same 70 cm telescopic antenna, depending on the frequency range, can get out again about the 3 S-stages (for example, in the 40 m band). Unfortunately, the reception breaks in from about 50 MHz, so that e.g. 2 m works better without the SAR32M in between.

On the other hand, if you connect a loop, the SAR32M shows its potential. You can compare it well with the MLA 30 +, which also provides very good reception results. The loop made of wire, which is supplied with the MLA 30 +, also fits optimally to the SAR32M. However, any piece of wire or cable can also be used.

The battery life is about 3 times longer than the Malahits DSP2 with a 3400 mah cell. The great thing is that this makes the SAR32M perfect for portable use.

Here are two examples on the 40m band, received with the SARM32M and a 70 cm telescopic antenna. First CW:

Again with SSB with only a 70 cm telescopic antenna:

The performance is very very good.

From inside

On Facebook I found the following picture of the inside view. The legs are firmly glued and usually break off when you try to open the lid (yes, I tried 😉 )

Malahit DPS2 – SDR Receiver from Russia

By 22 July 2021 Malahit DSP2, SAR32M, SDR 1 Comment

The Malahit DSP2 can be purchased directly from the developers in Russia. Since about May 2021, the version Malahit DSP2 is now sold.

Procedure of purchase:

  • Contact Georgiy per e mail in english: malahit_sdr@rambler.ru
  • Get on the waiting list and wait 😉
  • As soon as the Malahit DSP2 is ready, you will receive an email from Georgiy
  • Now you have to send the money via Paypal (via friends / family) to Georgiy
  • 19,500 rubles with shipping and 21,500 rubles with expess shipping

I was on the waiting list for about a month and the shipping with express, then took another 5 business days to Germany.

Features of the Malahit DSP2

  • Reception from 50 kHz to 380 MHz and from 400 MHz to 2 GHz
  • Modulations AM, CW, LSB, USB, DSB, FM, W-FM with CW decoder
  • The optional board is integrated, which you had to buy with the DSP1.
  • Hi Z and Pre Amp, which makes it possible to receive on shortwave even with a normal telescopic antenna of e.g. 70 cm (see videos)
  • Waterfall bandwith between 40 khz, 80 khz and 160 khz (in newer firmware 48 khz, 96 khz and 192 khz)
  • W-FM for radio reception with RDS support and stereo
  • Dynamic Retro Scale for W-FM visualisation
  • Extremely good noise blocker
  • Very good firmware support, there are many new firmware versions the last weeks

Additional Informations

Of course I tested the Malahit with the SAR32M antenna / 70cm telescopic antenna directly on the balcony and was positively surprised what I can receive everything, with a simple 70 cm telescopic antenna.

Here I show you the reception with a 70 cm telescopic antenna, which is adjusted with Hi Z and amplified with the Pre Amp of the Malahit. The reception is really amazingly good!

Here you can see the SSB reception with the SAR32M and a 70 cm telescopic antenna. In the 40 m band, the SAR32M, provides about 2-3 S-stages better reception. Amazing is also the extremely good noise blocker.

2 x 18650 mod

First I tested if the Malahit DSP2 can also be converted to two 18650 cells and it is possible. But on some boards standing capacitors were installed. Here you have to make sure that you push the speaker to the edge to create space to the left.

In addition, a small and deep 2 x 18650 holder should be used, as can also be seen in the picture. Here you have to be careful to shorten the soldering lugs to the housing.

BMS proctection for the 18650 cell and the Malahit DSP2

The Malahit DSP2 has no protection functions, like a BMS but it´s using the TP5056 charging controller. The charging controller has some protections functions while and after charging.

I added a cheap BMS to be safe, that my 18650 cell have a long life and is protected against a short circuit or things like this.

Bias Tee function, e.g. to supply an external Pre Amp

Then I tested the Bias Tee option and found that always the battery voltage is output. So from 4V – 3,3V (if the VBAT Standard options is activated). This could be problematic, because the cell voltage is to low for most devices.

SMA connector

Please note: The SMA socket problems are solved, because the developers are using a new SMA socket.

The only problems I had were related to the SMA connector: The included SMA telescope antenna had a too thick inner conductor and then apparently broke the SMA connector.

I then installed a U.FL to SMA adapter, which I still had at home, in the Malahit DSP2 and since then everything is fine again. Strangely, I had to try several of these adapters, until then one worked. With the others I only had reception when I connected the respective antenna to the SMA connector.

The U.FL to SMA cable used by the developers is extremely short and was installed in a sharp bend. So all the time there was a lot of voltage on the U.FL connector. As you can see on the picture, I used an adapter with longer RG316 cable. I also secured the cable to the relay with a small blob of hot glue to prevent the port from being live.

Better buttons

Nikolay makes very good and high quality knobs, e.g. for the Malahit DSP1 / DSP2. With shipping both knobs cost 13 € and can be ordered from him by e-mail: nickstrannik@gmail.com

More informations you can get here: http://mini-whip.de/2021/08/11/malahit-dsp-better-buttons/

Malahit DSP1 / Malahit DSP2 holder

Serhii is making a very nice holder for all orginal Malahits. More Informations you can get here: http://mini-whip.de/2021/08/04/malahit-dsp2-holder-from-serhii/

Bluetooth Mod

Currently I am working on a Bluetooth mod: I will install a Bluetooth board in the housing of the Malahit DSP2, that I will solder to the 3.5 jack output. So I can then use a Bluetooth headphones or speakers, without an adapter to the 3.5 jack socket, to plug from the outside. I soldered together a small housing for the bluetooth board to avoid possible interference.

The board on the picture can work with the 18650 voltage from 3,0V to 5,5V. I can receive and sent sound, but for the Malahit, only the sending part in needed.

Problems with the Malahit DSP2

The software problems like a wrong voltage are already fixed in the new 2,10 test firmwares. The biggest hardware problem for me was the bad SMA socket, but this problem is also already fixed at newer Malahits DSP2.