John, My uncle is a ham and likes to work 80m SSB running 100w. He has a problem staying connected to his ISP using a Garnet 56K flex internal modem whenever he keys his radio. He never had this problem using a US Robotics 33.6K Sportster internal modem.
Do you think any filters would help?

He's tried a number of ideas including those snap-together powdered iron cores from Radio Shack, but he hasn't tried ferrite beads.... All his efforts have been external to the puter (he has an internal modem)

Do you think that the change from 33.6K (analog) to 56K (digital) is the issue?

Any ideas are appreciated, including a willingness to try your filters.
Thank you.


John, I spoke with my uncle today - filter arrived on Friday and IT WORKS!! His check is in mail. He also mentioned it on air today and at least one of his buddies is also placing an order.
Thank you again - you've made us both happy.
Best Regards Jim

John, I got the filter yesterday and installed it into my modem line. It works great. I can now run a full kilowatt output when transmitting SSTV and I still remain connected to the internet.
It has completely solved my problem.
I still connect at 48kbps with my 56K modem so no degrading of performance.
Thank you very much for sending the filter. I really appreciate it.
Best regards,
Jim's uncle.

Click on the picture for RFI filter construction.


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