04 December 2015

$60 MR100 antenna analyzer - the output frequency quick test

Hi all,

I found on the internet that some of these Chinese analyzers like SARK100/MR100 have a serious problems with their DDS chip. This resulted in an output frequency being 1.5 times lower than what was displayed on the analyzer. To check if this was the problem with my analyzer I did a quick test.

Simply I connected the MR100 module to Agilent Frequency Counter in my laboratory and set the filter as same as input attenuator ON.

After I switched 160m thru 6m band range in order to check the frequency accurracy as same as stability.

The results can be seen on the pictures below:

The laboratory test conditions: T=25.5C +/-0.5C, Hum=45% +/-15%.

It looks like this module works as it should. The articles I read about this problem were all older articles so I guess it’s an old problem that doesn’t occur anymore?!

Hope it helps.

73 - Petr, OK1RP

$60 MR100 antenna analyzer - PC interface and post-analysis software test

Hi all,

after first few tests of the analyzer alone I tried to connect MR100 antenna analyzer to PC also... in order to test the post-measurement data analysing.

First of all after connecting the module to PC using USB cable you have to check if the FTDI chip adapter is already recognized by PC. I do not know if there is genuine FTDI chip implemented but I can suppose it isn't. In my case I found in Win Device Manager that FTDI chip is unknown and related driver is not installed. Luckily in my Win7 the system found automatically the proper driver and installed it in few minutes. So after finishing it the FTDI adapter is showed in Device Manager as that all is installed and it works properly.

After that you should find which COM port is assigned when the analyzer module is connected. In my case it was COM7 which will need to be added into the post-processing software.

The SARK100 Antenna Analyzer Software for Windows usable also for it's derivates is available here:
Another software for SARK100 and derivates is here:

Chinese language (partly in english) software for Mini60/SARK100/MR100 v0.9 is here:
Nice software that scans the SARK100/MR100 and plot the SWR on frequency by SM6WHY is here:

I decided to test for the first shot the software which was recommended by seller. It is the WinPCC for Mini60 and should work also with SARK100/MR100 in it's version 0.9 in Chinese language...

Run your antenna analyzer and click Config button to get PC Link, then click Down button to get Waiting Link... message.

After running the WinPCC software .exe file the main screen shows that Chinese vs english words is 50/50%...hi. The most important is left side command panel.

In the top left corner you need to select the proper assigned COM port then click on the left Chinese button which means "Connect" in english. After that you should see on the antenna analyzer itself that Waiting Link is already changed to "scanr" message which means it's connected and ready to scan upon PC software commands request.

Lowest left side command panel button means in english "Stop Scan", next button above is "Continue Scan" and next button above means "Start Scan". Screen with translated buttons to english is in improved later version WinPCC v.1.0_eng:

By clicking to the Start Scan button you should see scanning procedure and you should see the plot of SWR and other impedance parameters on the screen.

Here you can see the plot of very bad 50Ohms load measured in 6m band range including the Smith diagramm plot... nice feature.
If you will have problems with running the WinPCC then maybe the following link to Youtube will be helpful:

During my intensive testing I realized that this version of the WinPCC software has probably some bug in the code as the programm stucked many times when I tried to change some parameters like frequency range, step etc. The only solution is to quit the programm and run the .exe file again. Unfortunatelly you have to set COM port again...

Another problem is that if you want to use magnification button on the top (magnifying glass symbol) then it is always switching the plot into 3D vision... it is not possible to play with magnifition funtion in 2D only.

Well in general the basic WinPCC v0.9_ch software works. MR100 antenna analyzer PC interface is working. Connection or sync with PC is working and post-alanysis is possible. Now it will be funny to test other more sophisticated softwares... see links above.

Hope it helps.

73 - Petr, OK1RP

23 November 2015

$60 MR100 antenna analyzer toy


maybe you heard about the simple, cheap antenna analyzers which are available on different e-shops, auctions, shopping galleries etc. already.

There is one of them - $60 MR100 antenna analyzer toy - first test


I got it from our local radioclub staff last week for testing. He bought it somewhere on the internet for $60.50 fully assembled and tested. It does not look so bad for these money.

According to discussion with mentioned friend in the radioclub the cheapest way is to buy the analyzer module itself w/o BT option. The metal housing, BT, battery pack, etc. is up to you. Latest v.13 firmware should be available.

The full spec can be found in the manual here:

The toy is powered from 12V/500mA w/auto power off
Max. measured impedance/reactance (C/L mode) is 2000 Ohms
Max. measured freq. is 60MHz
Steps 100Hz to 100kHz

Mini USB port to PC

SWR, magnitude impedance, complex impedance, capacitance, inductance.
Derivate tests: ground loss, C, L, velicity factor, coax el. lenght, etc.

As it is using AD9851 DDS chip (Nyquist at 90MHz w/internal x6 multiplier clocks the DDS at 180MHz), the practical maximum output frequency from AD9851 is however about 70MHz. In my opinion as a third of the maximum DDS clock frequency for the AD9851 chip I prefer the maximum of 60MHz output frequency (lot spurs/aliases above). It is corresponding to the analyzer module spec.

After getting it from our local radioclub staff for testing I browsed on the net and I found that there is several clones and derivates from genuine SARK-100 like MR100, Mini60, GA-60 and many others. All of them are using the same generic EA4FRB f/w...

The genuine SARK-100 has been retired already. More information you can find here:

It is now replaced by new and much more sophisticated SARK-110.
More information can be found here:

I do not like the illegal chineese copies and MR100 unit is definitely one of them. 

Once I have it in hands I am planning to compare it with AA-200, MFJ-259 and even more I will try to make some comparison with professional Agilent E5061 network analyzers which I have available in my shack and lab.

I do not know more about MR100 analyzer as I have not schematic yet but I will try to make another video with functions and options available incl. calibration and some measurement.

The SARK100 Antenna Analyzer Software for Windows usable also for it's derivates is available here:
Another software for SARK100 and derivates is here:

Chinesse language (partly in english) software for SARK100/MR100 v0.9 is here:
More information can be found here:

Battery pack solution to power the MR100 or SARK100 by Ham Source:

Hope it helps,

73 - Petr, OK1RP

23 October 2015

A corrected version of QST's KSYN3A in K3 review


there is the link for corrected version of QST's KSYN3A board review which is replacing the erroneous TX phase noise plot in their last QST article:


Figures 10 and 11 have been updated by the ARRL to show the KSYN3A's actual transmit phase noise. As you can see, relative to the original synth, the KSYN3A has far lower noise at close offsets (toward the left end of the graph), and nearly identical noise at wider offsets (toward the right).

As Wayne, N6KR mentioned previously, this is a *transmit* phase noise plot. Phase noise is even lower right at the output of the synth module itself, accounting for the KSYN3A's outstanding RMDR (reciprocal mixing dynamic range, which applies to receive mode).

There is also explanation of their mistake in LF bands performance (500kHz/137kHz) measurement due to lack of proper modification on tested K3!

Thanks to Wayne, N6KR for sharing the link...

Hope it helps,

73 - Petr, OK1RP

20 October 2015

TMP-K01X-A1 connectors and cables for Elecraft K3


as it was hard to find the TMP connectors for making the calibration  of K3 in Czech even in nearest Europe in the past I tried to looking for distributor world-wide. I realized that some sales contacts does not work or links fails so I sumarized the actual links and informations again. 

BTW: What is the TMP connector or even TMP cable in K3 transceiver...?

It is one of the cables used for the second receiver module KRX3.
If you have the receiver module then you can start reading at page 22 of the installation and operation manual (assuming Rev. B of manual). Also it is used for KSYN3A, KAT3 to AUX and other modules inside of K3. You are not aware if you ordered K3-F (factory assembled) unit :) but for all those assembled their K3s by themself it is very known...
The TMP cable 12" is the Elecraft part: #E850339.

For all who would like to make coaxial cable for calibration of K3 instead of some temporary solution there are useful informations I guess:

Type: TMP-K01X-A1 connector 50ohms for RG-174/U coaxial cable type

Assembly Standard:


Quick assembly reference:

Sales links:

on eBay:




or here:


Hand-crimp-tool to buy:

The tips and hints discussed here:

The most important is to be ensured that the center pin is in it's socket properly, not bended, not misaligned during installation and as Guy, K2AV is saying..."The outer shell of the TMP plug can be connected without being fully inserted into the TMP connector. This can result in an intermittent on the center conductor that comes and goes with temperature change, or breathing hard, or changes in phases of the moon. The little flanges on the TMP plug should be nearly up to the TMP connector shell when fully inserted."

When it is in use I am recommending to check time to time (you do not need to do it before "each flight" :) the connectors if all of them are correctly inserted and if there is no rust, corrosion or silver coated TMP connectors are not becoming black...

Hope it helps.

73 - Petr, OK1RP

QST Review of KSYN3A synth in K3 has erroneous TX phase noise plot

Hi all,

although I am not re-posting the articles from the other sources to my blog over here in that case I am doing it as it is very important for many of Elecraft K3 users.

In order to better understaning the situation about the KSYN3A boards and parameters after the upgrade and for explaining the QST Review results there is the latest statement from Wayne, N6KR...

"Hi all,

You may have noticed that QST recently reviewed the K3's performance before/after swapping in a new KSYN3A synthesizer. While the review text was accurate (and complimentary), there was a significant error in the KSYN3A TX phase noise plot (Figure 10). This error made it appear as if the original synthesizer had lower (better) wide-spaced phase noise than the KSYN3A (starting where the plot lines cross), which is not the case.

We should have caught this ourselves before the article went to print. We greatly appreciated the League's efforts to determine the source of error -- equipment setup -- and re-test. The digital-print version of QST will be corrected, and a correction will also appear in the December QST.

The ARRL sent us the revised TX phase noise plot for the K3+KSYN3A that they tested. You can see it here: 

In addition they're testing a K3S. Its TX phase noise plot looks as good or slightly better: 

These plots (used with permission) were for 20 meters, and are also representative of the other bands, including 6 meters. The bottom line is that the K3S, or a K3 with a KSYN3A, has extremely low phase noise at both close and narrow spacings. In the case of narrow spacings, the new synth also significantly improves the RMDR (reciprocal mixing dynamic range) over the original, as described in the article.

Note that the above plots show *transmit* phase noise. In receive mode, phase noise with the new synth is even lower, especially at close spacings (under 3 kHz from the carrier).

There's one other measurement in the QST review that needs a disclaimer. As you may know, the KSYN3A allows the K3 (or K3S) to be tuned down to as low as 100 kHz, thus including the 137 kHz band. The review showed an MDS of -44 dBm at this frequency, while in fact it is more like -115 dBm. It appears that the K3 under test didn't have the RF board modification required, or the modified KBPF3A filter module.


I hope it helps and it will clarify more the results and measurement done by labs reviewed in QST magazine.

73 - Petr, OK1RP

13 August 2015

Elecraft K3 fans noise & FP high temp cure - Part I. (Intro)

Hi all,

after 7 yrs of daily operation of my K3 the fans sounds noisy. Even the rattling on low speeds (FAN1 mode) is noticeable and its getting me bothered. I asked Elecraft service for their kind help and they immediately offered me the replacement. So it was an excellent after sale service support, no complaint at all and I am waiting for arrival of the new fans to be replaced. 

The links for fans noise threats on Elecraft list:

At the same time I realized that my K3 after huge upgrade and now fully loaded is quite hot even in idle (RX mode). The temperature sensors in machine does not reporting any oddities and the PA/FP temp is stabilized between 38-40C in RX idle when the FAN1 speed is selected but...

When I am touching the cabinet's side it is quite hot as same as the right side of the front panel. The main reason is that 5V and 8V voltage stabilizators located on the right side close to FP are using the cabinet as heatsink! So I started to thinking about more CFM powerfull and even quieter fan which looks like very good upgrade option solving both issues together.

The link for Noctua fans replacement threat on Elecraft list:

An early K3 machines fans version was an Elina HDF6015L-12LB by Inaba Denki Sangyo, Japan. 

Airflow: 10.5 cmf
Noise: 21 dB
Speed: 2800 RPM
Static Pressure: 1.5mm
Current: 75 mA

Later K3 machines are equipped with fans UTEC AT6015L-12L2B-ND2 or ND5 by United Thermal Engineering Corp., Japan/Taiwan/China.

Airflow: 15.4 cmf at 24.8db
Noise: 24.8
Speed: 3000 RPM (at 12v)
Static Pressure: 2.21mm
Current: 100 mA

According to informations collected by Joe, KB8AP it looks like the Elina fans were used on earlier K3 machines with serial numbers <900 or so which is my case also (#778).

New possible replacement fan type is Noctua NF-A6x25 FLX by Noctua, Austria (probably it's not EU production also)

Airflow: 17CFM (29.2 m3h converted to cfm)
Noise: 19.3db
Speed: 3000 RPM (at 12 v)
Static Pressure: 2.18 mm
Cutent: 120 mA (.12 A)

The "6" number means 60mm size, "25" means 25mm tickness and FLX means Flexibility as fan can be fine-tuned for superior airflow or maximum quietness.

The link for Noctua supplier: http://www.newegg.com/Product/Product.aspx?Item=N82E16835608032

The link for Noctua manufacturer: http://www.noctua.at/main.php?show=productview&products_id=48&lng=en

I am thinking about the replacement and I am collecting as much as possible reviews or experiences from current users.

73 - Petr, OK1RP

29 July 2015

DXSummit updated - any other solution?


are you also disgusted with an updated DXSummit cluster? Even although I do not using the cluster so often I am really bothered with flashing banners, advertisement and complicated filters etc. So I looked for another solution months ago and found several different but nice options.

If you have the same feeling and you are looking for another way then try following solutions:


More informations is available here:



In that case just replace the band MHz value in between the underscore characters directly in the link... that's all.





I like the DXLite because of it's FOC filter feature and it works perfectly on the mobile devices and also UK cluster because of it's simplicity and clarity...

Hope it helps.

73 - Petr, OK1RP

24 July 2015

I am back on the air with K3 upgraded...

Hello all,
my K3 just arrived back from the Elecraft service where it was repaired and mainly completely upgraded. As I purchased my K3 early in 2008 and radio has never been upgraded or modified from that time so it was really neccessary. Now it is up to date with current production release, some strange issues are repaired and even more...
Second receiver KRX3A is installed with additional CW filters, new KBPF3A is installed too, KTCXO3-1 and K3EXREF is added also and mainly the newest KSYN3A synthesizers are installed. All is installed in both receivers, all is fully adjusted, tweaked and tested by Elecraft service guy. So I am able to come back on the air after months with somethink like the new K3S...!?
The shipping and repairing story is long and could be bothering so I will not talk so much about it over here. Shipping overseas is always nightmare and very dangerous. So I used double packaging. Inside of really big hard card box filled with huge foam padding was inserted the suitcase. The K3 was inside again loaded with foam padding.
The K3 luckily survived both overseas ways (sounds like that after turning radio ON...) even although the suitcase is ready to be scrapped after arrival!
The most important information and hint for readers! If You are looking for suitcase for Your radio then be very careful. Most of cheap suitcases are made just from pressed/moulded paper and covered by tiny (believe me... really tiny) aluminium foil. It looks like rugged box but it isn't!
My K3 had hard life on the way overseas...

Even also the padding inside of the cheap Chineese's "Alu boxes" are really tiny. Just few milimetres of the foam on the pressed/moulded paper cover can not provide enough protection for Your radio.

My K3 after arrival from the Elecraft, unboxed and removed from paddings. Still protected in plastic bag as the production released new radios.  

Well finally the radio survived it and I am going to testing all of the new h/w, features, functions and tools. I decided to install K3EXREF because I have working Rubidium FE5680A unit. So I am planning to put my K3 on that clock refference in the future. Also I decided to install the KBPF3A general coverage BPF into both receivers as I like lowbands and I would like to play with 500/137kHz bands using my K3. In my case I have external antenna BNC antenna input used for second KRX3A receiver as I really like to have all receiving pathes separated on the BNC connctors.

Fully loaded K3 rear panel looks nice, isn't it? :)

I would like to thanks a lot to Rene, K6XW from Elecraft for his exceptional effort and personal attitude in order to repair and upgrade my K3. Also I would like to thanks to Martin, OK1RR for his help with latest fw/sw release and personal macros uploading to my K3.

I will post my experiences with "quite new" K3 radio after huge upgrade soon. I have to learn all of the features and functionalities a bit...

73 - Petr, OK1RP

21 April 2015

RX ANTs switching topology for SO2R or M/2 contesting


as I was asked by several friends how I am handling more receiving antennas for lowbands in my setup I decided to share first version of my solution which I used last year.(now under reworking)

              The RX antennas switching topology layout ver.1.1

The very first version of the switching solution was developed for OK5T contesting team and it used blue SO-239 CX-xxx serie manual antenna's switches. The home made bandpass filters were simple 5-poles or 7-poles elyptic filters in aluminium boxes.

The most famous part of this solution were KD9SV front-end savers which I used in this solution with Martin's, OK1RR modification and worked like champ.


In general this solution allowed operator(s) to use any kind of 2-RX antennas on one of three lowbands 160/80/40m.

After some time I realized that I need to improve several things in this solution so now it is under reworking state. There is too many manual switches which is not so comfortable for operator during the contest. It is the 2-antennas solution only. There is no enough separation for SO2R operation etc.

...but maybe it will help to someone as it is so simple and cheap solution.

73 - Petr, OK1RP

24 March 2015

Front-end saver for LB antennas


If You are using a separate receive antennas, then you need a good protection circuit to eliminate the possibility of blowing out Your receiver's front-end while using these auxiliary receive antennas specially on low bands.

The protective circuit should be designed to disconnect the receive antenna during transmit, ground the receiver input when transmitting thus keeping RF out of your radio and eliminating the chance of blowing your radio's front end.

The perfect solution designed years ago Gary, KD9SV and I am using this genuine design in the alu-box for years without any problems.
Now I need more of these circuits because of more radios is planned in the ham-shack (SO2R etc.) and also the contest team OK5T need to improve the low bands setup...

Thanks to Martin's (OK1RR) great work I was able to use his slightly redesigned Front-end Saver based on KD9SV design using his PCB layout.

Very well-designed PCB with one-side bus wiring is easy to assemble and it will work for the first shot if you will not make the mistake...

The suggested PRMA 1A12 relays > molded rugged construction with internal protection diodes are used.

Steel painted box from local electronics shop is used in order to save building time and it does not look so bad.

Update 17July2017
There is not necessary to use the 2N2222A in metal TO-18 package! It is possible to use plastic TO-92 package as the most of parameters are same and there is not impact for that application. Most important is to identify the correct pin-out of your device!

There are several manufacturers producing several different versions like 2N2222A, P2N2222A, PN2222A etc. and the pin-out is NOT the same or standardized!

Check carefully your purchased version of transistors and identify the correct pin-out before you will assembly in order to avoid FES malfunction!

On picture above is an example of correct orientation of KSP2222A-E19 transistors TO-92 package on PCB...

After the final assembly I highly recommending testing the device for its correct functionality. It is much better to spend few minutes more instead of damaging your transceiver front-end stage because of non-working Front-end saver...

The short theory of relays operation in this circuit is here:

State nr. 1
(QSK T/R is floating)
Re1 - closed
Re2 - open
Re3 - open

In this case ANT port is connected to RCVR input port and AMP KEY port is floating.

State nr. 2

(QSK T/R is grounded)
Re1 - open
Re2 - closed
Re3 - closed

In this case ANT port is disconnected/floating, RCVR input port is grounded, and AMP KEY port is grounded too.

According to the theory of operation described above you can make easy and quick test using DMM before you will connect it to your radio and antenna.

1. Apply the 12V DC power to the circuit.

2. Check with DMM that ANT port hot pin is connected to RCVR IN port hot pin and that AMP KEY port hot pin is floating.

3. Using the tweezers or any similar tool short the hot pin of the QSK T/R port to ground.

4. Check that you are able to hear switching clicks of the relays when you are shorting the hot pin of the QSK T/R port to ground. Be very attentive as the chattering of relays is very quiet and fast so it is hard to hear in noisy environment. 

5. Check with DMM that in that state the ANT port hot pin is disconnected from the RCVR IN port (refer to point 2.) and it is floating. Then check that RCVR IN port hot pin is grounded. Finally check that AMP KEY port hot pin is grounded too. 

Update 18Sep2017
Some of the people asked me how to implement this FES into the Icom radios setup. So here is the layout example for wiring it together with Icom transceivers. (just quick pencil drawing...)

The "PTT output" port on the drawing means port on your transceiver where hot pin goes to ground while transmitting to control external equipment. In our case the FES. On the Icom radios this port is labeled as "SEND"!

See port 10 marked as SEND. This is your PTT for wiring it with FES.

The "Ext RX ant IN" on the drawing means port dedicated to connecting an external receiving antenna to your transceiver. On the Icom radios this port is marked as "RX ANT"! See port 1 marked as RX ANT on the Icom rear panel picture above.

Do not hesitate to ask for details if you need but all is clear from the pictures and circuit is pretty simple. Also let me know if you want to help with PCB or even with PRMA 1A12 relays for building your own FES...

With courtesy permission from Martin,

73 - Petr, OK1RP

Building document done by P. Ourednik, 20-Dec-2017. Document 12-17, rev.4.0

18 March 2015

RSGB Eclipse QSO Party 2015

good time to remind, because it is this Friday, March 20th...

The RSGB Contest Committee announces an "Eclipse QSO Party" in cooperation with the Propagation Studies Committee during the partial eclipse on the 20th March. Information about the experiments being carried out and links to other relevant sites are here

This is not a contest, but some of the RSGB Contest Committee software and web facilities will be used to collect and display activity reports.

The D layer of the ionosphere may not be as strong due to the eclipse, and stations on the lower bands – 1.8 MHz, 3.5 MHz and perhaps 7 MHz may be heard that would otherwise be inaudible during the day.
All available radio amateurs are invited to participate -- this is an opportunity to contribute to our knowledge of propagation and the ionosphere.
Those who wish to participate but cannot operate on the day of the eclipse may contribute if they have automatic skimmer / wideband RX (e.g. SDR) facilities. Please record the QSO Party and contact the Contest Committee to submit your recording.

See You on the air,
73 - Petr, OK1RP