HELP - Marc NR82F1 2nd Mixer IF Problem - Page 2 - UK Vintage Radio Repair and Restoration Discussion Forum

Phantomrose1999 · 26th Apr 2020, 12:52 pm

Mr 1936. I think you and others have clearly identified the problem. Bad design !

I was looking at circuits for low pass filters and found a great online site that calculates the components needed.

https://rf-tools.com/lc-filter/

So perhaps a low pass filter and an RF wide band amp from eBay.

Thanks to everybody, once again for sharing your extensive collective knowledge.

Phantomrose1999 · 13th May 2020, 4:55 pm

Hi All,

I took the Marc to Birbie island, which is outside Queensland to test its non-city performance. The reception on 40M band, listening to SSB HAM transmissions is beyond belief. One of the stations is 1700Kms away in Melbourne.

https://www.youtube.com/watch?v=Ghj0oZWW32U

The audio clarity is just unbelievable, in the video it's on wide band audio, if I switched it to narrow, all the hissing went away.

Shame the dual conversion is not enabled for the 80m band.

26th Apr 2020, 12:52 pm	#21
Phantomrose1999 Hexode Join Date: Mar 2008 Location: Melbourne, Victoria, Australia Posts: 289	Re: HELP - Marc NR82F1 2nd Mixer IF Problem Mr 1936. I think you and others have clearly identified the problem. Bad design ! I was looking at circuits for low pass filters and found a great online site that calculates the components needed. https://rf-tools.com/lc-filter/ So perhaps a low pass filter and an RF wide band amp from eBay. Thanks to everybody, once again for sharing your extensive collective knowledge.

13th May 2020, 4:55 pm	#22
Phantomrose1999 Hexode Join Date: Mar 2008 Location: Melbourne, Victoria, Australia Posts: 289	Re: HELP - Marc NR82F1 2nd Mixer IF Problem Hi All, I took the Marc to Birbie island, which is outside Queensland to test its non-city performance. The reception on 40M band, listening to SSB HAM transmissions is beyond belief. One of the stations is 1700Kms away in Melbourne. https://www.youtube.com/watch?v=Ghj0oZWW32U The audio clarity is just unbelievable, in the video it's on wide band audio, if I switched it to narrow, all the hissing went away. Shame the dual conversion is not enabled for the 80m band.