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:
http://elecraft.365791.n2.nabble.com/K3-Fan-noise-cure-td7606186.html
http://elecraft.365791.n2.nabble.com/K3-K3-fan-noise-part-XXLIV-td5091127.html

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: http://elecraft.365791.n2.nabble.com/K3-Fan-Replacement-td7592075.html#a7592266


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

 
Specs:
Airflow: 10.5 cmf
Noise: 21 dB
Speed: 2800 RPM
Static Pressure: 1.5mm
Current: 75 mA http://www.farnell.com/datasheets/1600097.pdf


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

 

Specs:
Airflow: 15.4 cmf at 24.8db
Noise: 24.8
Speed: 3000 RPM (at 12v)
Static Pressure: 2.21mm Current: 100 mA
http://www.utecusa.com/products/pdffiles/pid_1-45-152_%28SPEC%29AT6015L-12L2B%20ND1%2812-22-08%29.pdf
http://usquarecorp.com/products/pdffiles/pid_1-45-152_(SPEC)AT6015L-12L2B%20ND1(12-22-08).pdf

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)

Specs:
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)
http://www.noctua.at/pdf/infosheets/noctua_nf_a6x25_flx_datasheet_en.pdf
http://www.noctua.at/pdf/manuals/noctua_nf_a6x25_flx_manual_en.pdf

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

DXSummit updated - any other solution?

Hello,

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:

http://dxlite.g7vjr.org/

More informations is available here:
http://g7vjr.org/dxlite/
https://clublog.freshdesk.com/support/solutions/articles/53364-dxlite

or

http://dxcluster.ham-radio.ch/top_50_1.8_MHz.html

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

or

http://www.sk6aw.net/cluster/

or

http://www.dxcluster.co.uk/


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

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

RX ANTs switching topology for SO2R or M/2 contesting

Hello,

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.

http://ok1rp.blogspot.com/2015/03/front-end-saver-for-lb-antennas.html

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

Front-end saver for LB antennas

Hello,

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, OK1RR


73 - Petr, OK1RP

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

RSGB Eclipse QSO Party 2015

Hello,
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

NAS - Directional Power Meter R&S in lab

Hello,

the RF power meter is very usefull in the lab and for ham radio experiments it is even most important measuring equipment...

I like the Rohde&Schwarz in general. I like their equipment for long time and last month I was lucky to find their analog precise power meter NAS in very good shape available for acceptable price.

 

Directional Power Meter R&S^®NAS is the ideal servicing unit wherever power and SWR of all kinds of radio equipment have to be measured. Insertion units for the whole field of mobile radio - including GSM applications - make the R&S^®NAS a versatile unit and an investment for the future.

Two moving-coil meters

Autoranging

Battery operation

Automatic switch-off

High EMI immunity

Wide range insertion units still available up to 1GHz

The insertion units can be connected directly to NAS RF voltmeter or it can be connected thru extending cable.

 

I grabbed the NAS voltmeter including the Insertion Unit (1 to 30MHz, 1200 W - NAS-Z2 and even the R&S carrying bag has been included. So I got complete set to measure RF power on HF up to 1kW (1.2kW max.) with 6.5% of rdg for Z2 + 1.5% of selected range of NAS uncertainty. Great value to my lab for that money.

 

As I was a bit nervous how the postal service will manage the shipping I decided to pick up it by myself from Germany re-seller. So I made quick visit the Germany by car and after 9hrs on the way and 1000kms I arrived in the late night with my NAS equipment.

 

 

New NAS power meter in the lab...

 

Automatic self procedure after turning On the meter tells "all ok". The battery inside is newly replaced (thanks to re-seller pre-sale service) so I can go to follow the auto-calibration procedure according to user manual. It will need more time so not done yet but I am confident.

 

My first measurement has been done on the old Yaesu FT-990AC which showed me the max. power of this radio 110W at 50Ohms load. (no uncertainty calculated yet)

 

So in general all seems ok and I am happy to be able to measure RF power on HF precisely up to 1GHz.

 

If You will find this unit somewhere for acceptable price then do not thinking about it so long time and grab it.

 

 

73 - Petr, OK1RP