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Monday, 18 June 2018

Splashing Complete


Following my recent post back here about my bonkers SPE 1.3K-FA Amplifier, I thought I should post an update now it's back from its short vacation in Italy.

It has been back to the factory for three issues:

  • Front Panel missalignment
  • Very noisy fans
  • Attenuator fittment

So, I am please to report all three issues are sorted on the amplifier and the drive levels, whilst still somewhat bonkers, are very much more reasonable and within the range that I can actually control from the radio.

Luckily, my main radio (The TS-990) is extremely well thought out, and within the menu system you can set the granularity of the power out adjustment:

So  I can now set the output level exactly as I require on each band.

Here's a quick video of the amplifier now its back:

You can see the automatic band switching working - I have this working on both the Kenwood and my IC-7610 radios - you can also see that 5W drive now gives me 250W and 8W gives me full UK legal limit.

I haven't yet played with the in-line attenuator I made back here, but will do soon.

I've actually used the output from my MicroHam DigiKeyers to drive the CAT control from the rigs, so I can also keep the CAT line into the computer for logging and other control purposes.

All good.

Sunday, 17 June 2018

It's a Kind of Magic.....


6M AKA "The Magic Band" sometimes simply amazes me.

Today I have worked Cuba, Puerto Rico, Dominican Republic and Haiti.

Here's my all time 6M QSO log as a map:

Amazing, isn't it?

Sunday, 10 June 2018

TS-990 on 144MHz


Following some discussions at Ham Radio 2018, Friedrichshafen, I've done another example video of the TS-990 with a G4DDK transverter:

There's a document I've compiled on the transverter setup here.

Here's one of the halls full of goodies that I don't need from the rally - it really was very good:

and some of the test gear on offer:

And here is my very lovely Luna cat enjoying a snooze in the shack:

and finally, Miss Florrie Cat:

Good, egh?

Thursday, 7 June 2018

Taming the Amplifer


Following my recent purchase of an SPE Expert Amplifier I described here, I've been pondering how to keep the amplifier under control. It is currently back at the manufacturer for three issues:
  1. Extremely noisy fans;
  2. Bent front panel;
  3. Attenuation fitting.
I attended Ham Radio 2018 at Friedrichshafen this year and spoke to the owner (Dr. Gianfranco Scasciafratti I0ZY) of SPE while I was there. I tried to explain my concerns about such low drive level requirements and the reliance on ALC and associated risk of failure; the conversation concerned me because he didn't seem to want to listen to a word I said.

SPE have sent a video of my amp under test:

So hopefully it's on its way back to me now.

I've designed a thingamabob to put in-line with the amplifier as recommended by I0ZY to provide attenuation to the input drive level. Gianfranco suggested that the attenuation could be permanently in-line as on receive it "didn't matter". However, I'm not happy with that so I have come up with the following to switch the attenuation in line during TX and remove it during RX:

In reality the build looks like this:

There are quite a few bits in there, there are two coax relays (50 GBP), the connectors and the resistors in the Pi Attenuator (50 GBP) plus the case and other assorted bits and bobs (75 GBP) - so a total of 175 GBP just to tame the amplifier. Of course, I will need two of these if I want to use the amp as designed with two radios. I find it odd that they would recommend such a solution - why not just put sufficient attenuation in the amp to start with?

The gubbins has a good flat response from 0 to 50Mhz and also give us about 6.16dB of attenuation.

Throughout the build construction Florrie Cat has been assisting:

and somehow, you just know it's not going to end well:

Odd situation, don't you think?

Monday, 4 June 2018

Over the pond on 6M


After many years of trying, FT8 has given me my first QSO over the pond:

I'm rather delighted - it's quite an opening going on:

Good, egh?