Legacy AV with RF expansion board

[marqs]

A small number of Legacy AV boards with RF support is now available from me directly, 50€/piece. Depending on the reception they might be available from VGP later. Despite best efforts I was not able to fully mitigate EMI caused by OSSC Pro itself which gets coupled to the RF signal in certain degree (despite cable shielding and metal enclosure for sensitive parts). See the linked videos below and PM me if you’re interested purchasing a board.

Video1 (Dreamcast menu with default scaler settings)

Video2 (CVBS from RF chip hooked from on-board jumper to capture card directly. OSSC Pro in test pattern mode where interference caused by it is minimal)

UPDATE 20251121: most of the interference is avoided when using double-shielded antenna extension cable. Even better results were achieved with additional antenna amp (in which case cable quality between amp and Pro becomes less important).

Video3 (Connection to legacy_av_in via HQ cable, Dreamcast+RFU 1.5m away from Pro)

• This topic was modified 5 days, 14 hours ago by marqs.

[Zacabeb]

I’ve done some basic testing using the RF modulator in an old Philips VCR (VR 710) fed with composite video from a PS2, outputting PAL-G. The VCR was connected to the expansion board over a 2.5 meter (8 ft) cable with F plugs and an F to Belling-Lee adapter on the VCR end. The tests were made at a few frequencies in the range of 500-600 MHz with default and custom comb filtering settings.

I’m very happy with the picture over RF in this case. There was no visible interference with the above setup. Unfortunately the VCR I used has a problem with its audio input, so I couldn’t test sound demodulation there.

With a less well shielded cable, a weaker and/or worse quality signal (RF modulators in home computers and consoles tend to be worse than those in VCRs) and at other frequencies there may be issues, but I haven’t been able to test that so far.

[marqs]

Added a new video which shows results with double-shielded antenna cable. For legacy systems with built-in RF modulator with RCA/F-type output, I’d recommend using the following or similar accessories:

Quad-shielded RG6 cable
RCA – Type F adapter

There are now plans to bring the board available to purchase from VGP as I’ve sold out all of mine and have not received major complaints.

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