Sunday, December 30, 2012

Output detected on 472khz from the IC706

I mentioned a few days ago that I had measured a couple of watts output from the IC706 on 479khz although I'd not yet detected it on a receiver.

This morning I did some better experiments and set the IC706 up on a dummy load and placed the ICF-2001 receiver close by to the dummy load. I was easily able to detect the keying on the receiver, so that was excellent news.

The next challenge will be to find some sort of antenna matching arrangement. I have ordered a ferrite rod from eBay (despite trawling through my junk boxes in the loft, I couldn't find one). My first attempt at an ATU will, I think be similar to Roger G3XBM's - although more of a bodge I expect!

However, I was speaking to Adrian G4GDR yesterday on 2m. Adrian has been one of the 500khz permit holders and mentioned that he had made a variometer out of a carpet roll and some rods. He very kindly invited me to inspect it, which I will certainly do.

I'm not sure how viable the IC706 will be for 472khz, but perhaps it will be possible to scrape a local contact or two.


PE4BAS, Bas said...

I do follow this post with interest as I use a Icom 706 myself. I even got that Sony SW receiver ;-). Didn't know the Icom is able to produce a signal on 472 KHz. 73, Bas

Tim said...

Hi Bas. It's definitely worth a go! Probably best to keep the power quite low, but I can see 2W into a dummy load at the lowest power setting.

I don't yet know how good the receiver is!

73, Tim

Unknown said...

A receive convertor with an IF at 160 or 80 meters would be helpful
You can manually switch the radio between receive and transmit modes.


Daniele in3fci said...

Hi. I am in3fci Dani from Bolzano
I have tested ic706 on 472 khz power out 5 watt with power setting on 3 of the radio tested wit listning antenna, 110 meter wire with16:1 home made balun for lf e mw. Work great i tune with home made preselctor and the signal cam out perfectly reception is fantastic ,any question....... i thik !
Is possible to damage the radio with increasing power out or is possible to modify the lowpass filter of the radio.
An external PA is better in this case ? I work prettly qrp .
So that is all
Best 73

Tim said...

Hi Dani,

Great to hear from you. I am very interested to hear you have been using the IC706 too. I would be interested in the matching that you built for your antenna.

Like you, I was thinking it was best to keep power low, in case there was a problem with the low pass filter!

Vy 73, Tim G4VXE

Daniele in3fci said...

Hi Tim
Now i have work of the antenna. Now is tuning perfectly on472 with coil and capacitor .. A simple parallel resonant circuit. My antenna is big but no high a good ground help a lot.IC 706 work great i put power to 1 max 2 in the power setting menu. I have see the schematic from 706 this has a low pass filter from 2 mhz the problem is the trasformer from pa circuit. So a external pa is better in all case. With 3 watt listning me M0 G4 DK PA I7 ......
This is for me a great result
Low low power ..hihihi
A question . Can anader rtx work in472 like ic 706?and is possible to find modify for commercial rtx to work on this band?.i will find a kit for pa i dont have time to build from zero. . For the moment that is all . Hope hot hear you in472khz. Sorry for my maccheroni english!!!!hi!!
Daniele de in3fci/qrp

Tim said...

Hi Dani,

When you posted your question about modified commercial transmitter, I didn't know. But apparently there is a Marconi OceanSpan unit. I don't know much more than it was mentioned the other day.

How are you doing with the IC706 now?

73, Tim


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