FTdx3000 – Omnirig Digital Mode

Hi All,

Just a little something I’ve run in to when setting up my new FTdx3000. I had an OmniRig setup with my previous FT-450; worked like a charm, including SDR-Console tracking, etc etc. I run everything trough OmniRig as I don’t need any virtual serial ports that way, and it works pretty fast and stable. Even WSJT-X works with it.

Here’s the deal though: the supplied FTdx3000 profile for OmniRig, puts “Digital-UP”-mode in RTTY-DATA mode instead of USB-DATA mode. To fix this, I’ve created a modified profile. Just put it in the Afreet OmniRig install folder and select the profile in OmniRig. Should save you all some head-aches. Click here to download it.

Here’s my menu settings list:

  • 067 – Data Mode: Others
  • 069 – Other Disp: 1000Hz – This is needed as the FTdx3000 adds a 1000Hz shift in data mode – utmost importance for FT8!
  • 071 – Data Lcut Freq: OFF
  • 075 – Data In Select: USB
  • 077 – Data Out Level: 1

This way – you don’t have to switch any mic settings – data modes have their own profile.

73 de ON8AD

ICOM IC-910h – Preamp bias troubles

Recently I was asked to take a look at a IC-910h VHF/UHF all-mode transceiver which had developed an issue where the bias kept being enabled. Even on transmit and when the preamp wasn’t enabled. It luckily didn’t cause any havoc as the operator’s antenna wasn’t DC shorted at the time..

If you look at one of my previous posts – you’ll know how a basic bias circuit works (check it out here – SEA remote ATU bias & mods).

The problem here, was that there was no way of turning it off and on. Nothing seemed to be burnt out or shorted on first sight. So what does this look like on the schematic?…

I’ve traced some lines to show you how things work. Q702 is a PNP transistor – a Rohm 2SB1132 T100R. This is the main switching transistor. Rated 500mA. Q703 is a DTC114EUA T106. A bit of a special beast. It’s a “digital transistor”. It has built-in bias resistors to enable the configuration of an inverter circuit without connecting external input resistors.

So to troubleshoot, I first checked if VPRI was being switched from the main processor with reference to ground. It was. Pfew – no main processor issue. Next step was to check if Q703 actually did any switching: it did as well. Hmm, odd.

Checked Q702; and it wasn’t shorted when checking in diode test from Base to Collector, or Base to Emitter. Maybe C703 or R702 failed? Nope, not that either. Any thin whiskers around due to lead-free solder? Nope.

I still suspect Q702, as for some reason, it conducts, without anything applied to the Base. (Otherwise known as a “Leaky” transistor). To confirm, I replaced it temporarily with a bog standard BC560. Works like a charm. Leaky transistor confirmed. Here’s the testing bodge in all it’s glory.

I quickly ordered a couple of Rohm 2SB1132 T100R from https://www.arrow.com/ (I kind of like their fast service and clear website to be honest..). Delivery took a little longer than usual due to the fact that it was in stock in a HK warehouse and I’m in the EU.

Remember to really clean up the old pads when working with SMD components. It’s just much nicer. I used Chemtronics fluxed solder wick here. Pads clean up nicely with it.

Here’s the new part installed. Looking great.

And confirmation it works and can be switched on/off..

The UHF part is similar; so if you run into issues where bias is kept on with your IC-910h; make sure to take a look at these components. The UHF part is a bit trickier, as you need to disassemble the entire PA unit..

73 de ON3AD – Jeffrey

FT-2000 – Deaf as well?

I recently had a look under the hood of an FT-2000; and just as I’m done repairing two FT-897; I notice that the FT-2000 should be a suspect as well! Yaesu: what gives?!

You can see the same white oxide leaking out of the porous plactic of those filters.

A warning to FT-2000 users: you should check them periodically.

Yaesu FT-897 – Deaf on receive

In our local ham radio club ( UBA-ARA ) – two of our club members had a Yaesu FT-897 who seemed deaf in certain modes. I took both transceivers home with me and took a closer look.

Upon opening the transceivers, I quickly saw what looked like water damage on the IF crystal filters:

You can see some white deposit on those filters. My guess is that after re-flow/wave soldering these boards, Yaesu probably washes these PCB’s. However, the plastic used in these filter either is brittle, porous, or the bottom isn’t hermetically sealed.

Removing these filters is a pain in the ass. And I’m not overreacting here. The ground plane in this PCB is quite good and you can really struggle to get the solder out. (lead-free as well!). Here’s the PCB with the filters removed:

Looking at the flux in other places on this board, I suppose this transceivers has had work done before…

I opened up one of these filters to get an idea of the damage done. A sharp blade does the trick:

You can clearly see the copper oxide. No wonder this thing was deaf!

Anyway, it’s worth opening up your transceiver if you have an FT-897 to check and see if there’s any of that white “powder” on those filters. Big red flag if you see it.
Here’s a picture with already one new filter in place. Make sure to put the right filter in the right place…

Yaesu FT-450 – deaf on higher bands

I’ve always wondered why my FT-450 I bought second hand had a lower RX level on the higher bands, starting around the 20m band. I took a look at the schematic, and the input on the RX side is very classic: a DC blocking cap and protection diodes.

Protection diodes, wait – those aren’t RF protection diodes; they are bog standard SMD red LED’s! What was Yaesu thinking here? (“Let’s save 2 cents?”). Only reason they might have used these (and the only reason I can think of) – is that they maybe have a low capacitance. But seriously, Yaesu.. ?

Anyway, I set my multimeter to the diode setting and quickly realized that one of them was shorted. Really, who tries to use LED’s as protection diodes? Really not up to the task. Here’s one that was still working. The picture gives a good indication where you can find them on the PCB (underside of the transceiver).

The diodes are placed anti-parallel to clamp any over-voltage/ESD. But there are better parts to be found. I came across the Infineon ESD0P4RFL. It’s quite a bit smaller, but we can move the part a bit. It’s actually made for these purposes:

  • Very low line capacitance: 0.4 pF @ 1 GHz ( 0.2 pF per diode)
  • Very low clamping voltage
  • ESD protection of RF antenna / interfaces or ultra high speed data lines acc. to:
    • IEC61000-4-2 (ESD): ± 15 KV (air / contact)
    • IEC61000-4-4 (EPT): 40 A (5/50 ns)
    • IEC61000-4-5 (surge): 5 A (8/20 μs)
  • Ultra small leadless package:1.2 x 0.8 x 0.39 mm³

Read that last line, yes – THAT small

I cleaned up the original location of the LED’s with some solder wick; also cleaning any flux residue on the board with IPA as flux does have a capacitive effect. I removed a bit of solder mask up the trace a bit as to fit the component correctly and applied some solder paste before re-flowing the part. Measures like a standard diode with a voltage drop of about 0.6 V – so easy to verify. It’s really small compared to the original LED’s – check it out at the bottom right of the trace.

Overall if you have a FT-450 – check that these aren’t already blown. I see *some* complaints about bad RX on these transceivers, but that’s really not the case *if* these diodes aren’t blown. So check up front, and replace “just in case” would be my advice.

Sea 1612c Remote ATU – bias & mods

So I acquired a SEA 1612C remote ATU for cheap, but without an enclosure. I figured I’d buy my own enclosure anyway, so no big deal.

As I didn’t want to use any remote cable at all, I had a little challenge:

  • I need to give it power. Okay, that can be done via a bias-tee. The tuner isn’t made for it, but can be modified.
  • I need some way to be able to “tune-on-demand”. I settled on a small Arduino Nano, but will eventually do this via a ESP8266 (I can remote control it via WiFi then)

So what is a bias tee? It’s actually no more than a handful of components: a couple capacitors, some ferrite to make a choke, and some nuts, bolts, sockets.. and a fuse. You double up these components to make one for the other side as well.

So what’s it look like? Well, see below. C1 in my case is 2x 10nF – 3kV capacitors (in parallel – so 20nF in total). F1 is a Ferroxcube 4C65 ferrite, wound with about 30 turn of magnet wire. It makes a nice 3-30MHz choke when testing it with a Vector Network Analyzer. F2 is a 3A fuse.

So how does it work? Well – RF in to the left – the capacitor blocks any DC; the choke blocks any RF going back into the DC supply. Build the same thing twice, and you can run DC over the same coax. Easy, nice, elegant. Great!

Alright, that’s one solution. Now we need to be able to “tune on demand”. There’s a pin called “DTN” on the connector block of the SEA 1612c – “Demand Tune”. The thing is:

  • This only works when it already has a stored tuning
  • Keeping this permanently low (instead of the usual “high” impulse when triggering something) locks the microcontroller up, as it’s on an interrupt pin. So no easy fixes.

Simple solution: slap on an Arduino which pulls DTN down, only once, after being powered on 3 seconds. Just an NPN and an Arduino, collector to DTN; gate to the Arduino output pin and emitter to ground.

I piggybacked the Arduino on the 5V regulator on the board (7805 regulator) so in terms of power: no issue.

To force a re-tune, I press a normal-close momentary switch which breaks power to the tuner. Upon release power is fed back to the tuner. I press PTT which recalls the previous setting. After 3 seconds, the Arduino pulls the DTN line low, causing the tuner to clear the memory setting. I can then put some RF on the tuner and it’ll force re-tune for that frequency.

I found a nice enclosure for the tuner at Arli24.de, a German web store. The enclosure is IP65 rated, well priced, has a window, and comes with all locks and mounting hardware.

I used two aluminium “L”-profiles to securely place the enclosure in the ground. Here’s the end result feeding my 40m long multiband half-wave end-fed antenna.

Yaesu FT-450 – SDR Panadapter & SDR-Console

I was recently gifted a SDRPlay RSP1 (thanks again ON3HVP!) and have wanted to install an RF-tap for a long time in my FT-450.

Now, there’s a couple of ways you can do this:

  • Get an extra RX antenna (duh..)
  • Tap at the antenna port (but you’ll need to disconnect on TX)
  • Tap at the RX circuitry
  • Tap at the IF (in case you’re using an RTL-SDR which doesn’t handle HF too well..)

In our case, we’ll tap at the RX circuitry. It doesn’t see any TX power, so it’s all safe. There’s one caveat: you can’t just solder an extra wire and be done with it. If you connect an extra cable and receiver; you’ll load this stage down, causing your receiver to be less sensitive. Not something we want on HF!

Enter a great little board by G4HUP (who is sadly an SK at the time of writing…). The board Dave designed is essentially a high-impedance buffer. So it avoids loading down the RX section, while making sure it has adequate power to drive the input of the RSP1.

Seeing we want the full spectrum delivered to the RSP1 – I chose the “PAT V”-board: no filtering, straight from RX on the transceiver; to the RSP1.

Here’s how it’s all connected (click the image for a large version):

FT-450 Panadapter

FT-450 Panadapter

Basically, we’re tapping at the little BalUn next to the white relay; and we’re powering the buffer from a regulator providing 12V – but only at RX (it mutes the adapter on TX by not providing any tension).

You might ask: “Why aren’t you using a thin coax?” – It’s a recommendation from G4HUP himself: it adds less capacitance which would in turn load down the RX and thus decreasing the signal.

OK – so we got the adapter installed, we have the RSP1 connected and OmniRig is working like it should. (See other post..)

Enter SDR-Console V3 with… External radio support (you can see where this is heading… HI). If you have OmniRig set up; you can enable external radio support in the SDR-Console options. You’ll have to restart the program once you do that.

You’ll notice an extra window in the DSP setting. Enable the “play” button and the “tracking” button. That’s it. You PC (and thus RSP1) is tracking your radio, but also the other way around: If you see a signal in the waterfall: click it and you’re QRV on the other station’s frequency.

Even better, my logging program (Log4OM) uses OmniRig as well. So I could even click an entry on the cluster, Log4OM sends a CAT command; the transceiver tunes to the frequency; and so does SDR-Console V3.

Awesome!

sdr-console V3

SDR-Console V3

Yaesu FT-450 and Omnirig

Lately I’ve been having issues where my CAT commands from Omnirig would time-out or vice-versa. (Notably the dreaded “Rig is not responding”) I had been looking high and low why or who was to blame. Factory resetting didn’t change a thing, nor did changing the serial cable. The settings in Omnirig didn’t matter – nor did serial speed. Hmm, maybe RFI is to blame? – Nope.

Turns out – the issue is in the driver for the CP210x dongle! If you use the latest version (at the time of writing – v6.7.5) then you’ll experience these mishaps. (I’m betting other rigs using this chipset will be affected too!).

In short – you want to revert to a previous version. I got hold of v6.7.3 and the time-outs are 100% gone. Seeing it’s hard to find this version – here’s a link to it.

Edit 2018-apr-27: It’s better to select the FT-450D model, even if you’re using the FT-450 (original..). The “D”-profile will return the TX/RX status as well.