Tuesday, March 31, 2015

Feature upgrades for the 432MHz Solidstate Amplifier

Having upgraded the 2m solidstate amplifier I decided I should do the same upgrade to the 432MHz Amplifier.  The original writeup is here The Two same features were needed:-

1. There is no bypass position, so one cannot test the antenna SWR before letting the amplifier use it. This cost of the lack of this feature was learnt the hard way on my 70MHz amplifier
2. Currently the Elecraft K3 keys the DEMI transverter which keys the amplifier which sequences the antenna relays and preamplifier. There is no output for the Amplifier to properly sequence the DEMI Transverter along with the antenna relays and preamplifier, this needs to be added.

A bypass switch was added to the front panel along with a bypass LED. A phono socket was added to the back panel for the Transverter output. An hour was spent adjusting the PIC code and all feature additions were accommodated.




Monday, March 30, 2015

Feature upgrades for the 144MHz Solidstate Amplifier

Having got the 2m Anglian up and running it was time to  interface it to the 400W solidstate Amplifier.  Two features were needed:-

1. There is no bypass position, so one cannot test the antenna SWR before letting the amplifier use it. This cost of the lack of this feature was learnt the hard way on my 70MHz amplifier
2. Currently the Elecraft K3 keys the amplifier which sequences the antenna relays and preamplifier. There is no output to properly sequence the Anglian Transverter along with the antenna relays and preamplifier.

A bypass switch was added to the front panel along with a bypass LED. A phono socket was added to the back panel for the Transverter output. An hour was spent adjusting the PIC code and all feature additions were accommodated. Also incorporated was the LCD showing the alarm trigger levels at amplifier startup


Thursday, March 19, 2015

Locking the 2m Anglian Transverter to an external reference

G4DDK had mentioned it was possible to Injection lock the 116MHz oscialltor of the Anglian Transverter by Injecting 116MHz into the LO port of the Transverter module. In my parts collection I found an early 116MHz DFS module, similar to the design used on 96MHz described at  at http://g4fre.com/dfs9096.pdf  except it used (10MHz * 11)+(3 * (10MHz/5)) and three 116MHz crystals. The output level was ideal at +3dBm While monitoring GB3VHF it was found to put the transverter onto the correct frequency as opposed to the free running frequency.

Having proved it worked, I then mounted the DFS116 inside the box. A slider switch (less likely to get damaged portable) was used to remove the 13V from the DFS when there is no external 10MHz applied. The output from the DFS did not need disconnecting from the transverter LO input when powered off.

Sunday, March 15, 2015

Using the Anglian 4m Transverter with ANAN-10 and N1MM logger+

This morning I decided using the K3 with the new Anglian 4m xverter for the 70MHz contest would be too easy, so I decided to try hooking it up to the ANAN-10 and trying to use it with the N1MM Logger+ software.

Its easier to use the TX port output with a 20db attenuator than the xverter port output. If you do use the XVERTER output, the TX port has to be terminated, as it still produces 0.5W output and Powersdr will complain of SWR alarms. As previously determined, a 30MHz LPF is always needed on the output.  I used the EOT output pin 25 of J16 to key the transverter. The Mic input had previously been wired for the KX3 PTT microphone

Powersdr makes the ANAN-10 look like a TS2000 to the N1MM software so N1MM could track the frequency through a com0com virtual serial connector.  I used a COM4<>COM5 pair.

Tuning Powersdr through the beacons was a challenge, so, having remembered I had a Griffin powermate USB knob I Installed that on the windows 7 64 bit machine (the driver/software on the griffin site for Vista worked fine). I configured it to tune the rig up and down. This worked fine BUT ONLY if Powersdr had focus. When N1MM had focus the tuning knob did very strange things to the frequency.  This was overcome by deleting the default setting entries in the Griffin setup software. I then discovered (after reading the N1MM documentation) it was possible to tune the radio (only in run mode) from the keyboard. This scheme worked well.

The transverter produced 7W into my loop antenna in the loft. A few QSOS were made on SSB with locals then my thoughts turned to CW. Initially I used the Powersdr CW keying facility as I failed setting up the N1MM keyer to send cw through the CAT connection. Unfortunately the paddle connections were swapped over so G4BRK got to suffer my cw with the paddle operated upside down ( you can swap the paddles over in Powersdr I later found out, but its in the <DSP><CW> tab!) I then worked G4BWP (my best dx) then G4RFR on CW.

After the contest I went back to looking at the N1MM keying. I discovered, (also in the <DSP><CW> tab) that, whilst leaving the primary cw connection as "radio", (ie its key jack) a secondary connection may be set as a com port (COM6 in my case) and the RTS and DTR set to convey the cw and PTT signals from N1MM. Another com0com virtual port pair was set up (COM6<>COM7). In N1MM in the <configurer><hardware> Tab,  COM6 was set up as a "CW/other" connection with RTS and DTR appropriately assigned. This then worked fine




Friday, February 27, 2015

Anglian 4m Transverter

Having had success with the 2m Anglian I decided it was time to finish its cousin the 4m Anglian Transverter . I also put the tinplate box module  in a cabinet along with the 7W power module mounted on a heatsink on the back panel, using the same metal box from makerbase.co.uk.  A metal chassis plate was needed for the inside of the box to mount the modules on, I found some ali sheet on ebay that could be supplied cut to size. Note that as supplied there is a lot of "paint to paint" contact between the metal box parts, so a lot of scraping was done to get "metal to metal" contact to help screening. To further help, a piece of ali angle was mounted between the back panel and the chassis plate (as can be seen in the lower picture:-





The transverter was setup so that 0.5mW from the K3 on 10m produced 5W on 70MHz, which is the ideal drive level for my amplifier

Thursday, February 26, 2015

Anglian 2m Transverter

A while ago I populated the pcb for my G4DDK 144MHz Anglian transverter. I finally got round to putting it in the tinplate box and tuned it up. All was well, so I decided to put it in a cabinet along with the 8W power module mounted on a heatsink on the back panel. I found a couple of cheap Metal boxes off makerbase.co.uk A metal plate would be needed for the inside of the box to mount the modules on, I found one off ebay that could be cut to size. Note that as supplied there is a lot of "paint to paint" contact between the metal box parts, so a lot of scraping was done to get "metal to metal" contact to help screening. To further help, a piece of ali angle was mounted between the back panel and the chassis plate (as can be seen in the lower picture:-

To add heat transfer, I wanted to mount the power module directly on the heatsink rather than mount it on the back panel then on the heatsink. To do this i would need to make a rectangular hole in the back panel. Discussing this at the Malvern Radio Club, it was recommended I used a nibbling tool. I found one on the internet for 9.00 shipped. It is a brilliant tool; I can see a lot of use in its future!



As there is no conductivity between the metal parts of the case due to the paint a lot of time was spent removing paint to allow good electrical contact between metal surfaces. I also add a piece of ali angle between the back panel and the cahssis plate.

The transverter was setup so that 0.5mW from the K3 on 10m produced 5W on 144MHz, which is the ideal drive level for my amplifier

The 144MHz connetors were spaced to allow an external coaxial relay to be attached with a pair of BNC to BNC male adapters. This allows use with a sngle antenna feeder. Normally when using a masthead preamp the two connectors are used, eliminating the prospect of transmitting up the back end of the preamp


Friday, January 23, 2015

K3 remotehams software with N1MM

Now being able to control the K3 remotely, I next wanted to integrate It into the N1MM contest software. To do this I would need a virtual com port setup on the client PC that would allow the serial data to be seen from the remote K3. Fortunately the remotehams client software under "options" has  "Elecraft K3 emulation" To install the drivers for this,  one needs to tick the install virtual port when installing the client software, then when that has successfully installed, under "options" "Elecraft K3 emulation" I chose com2 as the port to create under the "create virtual port" tab.. Note the data rate is fixed at 38400bd.


After this was done I chose "com2"  "k3" 38400" under "config" "config ports...." "hardware" in the N1mm software and the remote K3 acted exactly as if it was local


Note this same technique can be used in any software requiring to see the K3 on a serial port. Fldigi, WSPR v2.12 and logger32 have all been successfully tried