AN612 Balanced Modulator - Page 2 - UK Vintage Radio Repair and Restoration Discussion Forum

Wendymott · 1st Apr 2020, 11:26 pm

Thanks Andrew.... If I am making anything.. I usually make pcb's.. as I want to make it as near the final layout.. with minor tweeks if necessary.. Most of my projects start out as modules.. then I integrate if necessary. OK the unbalanced modulator.
My intention is to go 6m, 4m and 2m... I was going to inject the LO on the low side, but the AN612 seems to cope within 1db..on the high side.

Andrew2 · 2nd Apr 2020, 9:21 am

A small update. I began to wonder if it needed those balancing pots, after all the NE602 seems to do quite OK without them.
So off they came, and in this state I got only about 30dB of carrier suppression.
With the pots connected and carefully twizzed, 70dB of suppression is fairly easy to achieve. Any more and it gets tricky, but that's quite enough anyway.

Wendymott · 2nd Apr 2020, 7:50 pm

Hi Andrew. For the price of a couple of trimmers..another -40 db is no contest. For some reason Im getting about -60 db, but Im happy with that.
I made a 4 pole 6 metre filter today, after the "lashup" and its not performing as well as the lashup.. but it will.

1st Apr 2020, 11:26 pm	#21
Wendymott Octode Join Date: Jun 2013 Location: Huddersfield, West Yorkshire, UK. Posts: 1,795	Re: AN612 Balanced Modulator Thanks Andrew.... If I am making anything.. I usually make pcb's.. as I want to make it as near the final layout.. with minor tweeks if necessary.. Most of my projects start out as modules.. then I integrate if necessary. OK the unbalanced modulator. My intention is to go 6m, 4m and 2m... I was going to inject the LO on the low side, but the AN612 seems to cope within 1db..on the high side. __________________ Should get out more. Regards Wendy G8BZY

2nd Apr 2020, 9:21 am	#22
Andrew2 Nonode Join Date: Mar 2010 Location: Dukinfield, Cheshire, UK. Posts: 2,037	Re: AN612 Balanced Modulator A small update. I began to wonder if it needed those balancing pots, after all the NE602 seems to do quite OK without them. So off they came, and in this state I got only about 30dB of carrier suppression. With the pots connected and carefully twizzed, 70dB of suppression is fairly easy to achieve. Any more and it gets tricky, but that's quite enough anyway. Attached Thumbnails __________________ Andy G1HBE.

2nd Apr 2020, 7:50 pm	#23
Wendymott Octode Join Date: Jun 2013 Location: Huddersfield, West Yorkshire, UK. Posts: 1,795	Re: AN612 Balanced Modulator Hi Andrew. For the price of a couple of trimmers..another -40 db is no contest. For some reason Im getting about -60 db, but Im happy with that. I made a 4 pole 6 metre filter today, after the "lashup" and its not performing as well as the lashup.. but it will. __________________ Should get out more. Regards Wendy G8BZY