HE'S the Jekyll and Hyde of Irish radio and no doubt. There was Joe Duffy Tuesday morning (The Gay Byrne Show, RTE Radio 1, Monday to Friday) in the studio, doing his best i.e. most cringe inducing and soporific Gaybo imitation. Then there he was 48 hours later, out the road a piece, re cast as Hero of the Hour.

First the bad news. When people complain to me as they are occasionally wont to do about that Joe Duffy and the way he's trying to be Gay, I tend to go all Irish Timesy, on the one hand on the other hand it's more complex than that.

I slipped from the old lofty perch, however, when Tuesday's Studio Joe started into a "comic" turn about why in God's name, merciful hour, etc, anyone would want to hear a Sex Pistols reunion. Yes, okay, I might have been missing some biting irony, but it seemed the joke was premised on the old it's just a lot of noise critique and Duffy's line about a few seconds of Pretty Vacant driving his listeners out to Mass cut close to the bone given the unwelcome age profile of the audience.

You'd be hard pressed to think of a dozen songs in the last 20 years with more power and vitality than Pretty Vacant. Mine is not an especially unique opinion and if he keeps up this geriatric humour, Duffy himself will be the only under 45 left listening. This one certainly switched over to Gerry Ryan.

Thus missed hearing, live, one of the most dramatic pieces of radio in yonks. This was OBU Duffy on Thursday (with the Real Gay in studio), returning to the scene of one of his finest recent hours. Duffy was in Mulhuddart, where last year he spoke memorably with the families of teenagers killed in a "joy riding" accident this time he was looking into the potential eviction of one of those mothers and in the course of the programme the potential changed starkly into actuality.

Most readers will have heard or read by now of the three vehicles pulling up outside (presumably with their passengers listening to Gerry Ryan on the car radios) and the burly lads from the Corpo making an unceremonious entrance.

While doing the necessary in terms of radio drama (Don't push me! Don't push me!"), Duffy was earnest, humane and insistent about the real life consequences of these men just doing their jobs.

And he was all these things safe in the knowledge that his unflinching stance would be dramatically countered by Gaybo's conservatism. This was great radio partly because, as has happened before, Byrne's apology for the status quo and the bootstrap ethic clash with Duffy's sympathy for the distressed and downtrodden.

And all the time, it was calling attention to an awful situation for many tenants. Well done, OBU Joe - now could you just get Gay - (or anyone!) back in the studio on Mondays and Tuesdays and kill off that doppelganger?

A funny sort of sympathy seems to have driven George Catlin. This week, Booktime (RTE Radio 1, Monday to Friday) features Roger Gregg reading his own excellent, ethnographically correct adaptation of Catlin's letters from the American west in the 1830s, Medicine White Man.

Catlin decided to uproot himself, from Pennsylvania when he saw native Americans in Philadelphia and realised that a noble people was being exterminated. His vocation? To paint them before they died out altogether.

You might say: fat lot of good that did the Mandan people of what is now North Dakota. You'd be right: and as you'll learn if you hear out the series until Friday - a recommended activity - it didn't do Catlin the world of good either. However, Catlin observed the Mandans quite astutely, and Gregg has done a fine job of bringing the best of these insights to the fore - while, leaving us to mull over the position of the observer himself.

Catlin's seemingly casual acceptance of the genocide implicit in America's manifest destiny had curious echoes in Tokyo's Burning (RTE Radio 1, repeated last Wednesday), a chilling Australian documentary about US firebombing of the Japanese capital.

It's the sort of thing we've heard about the A bomb Manhattan Project before. But there was if this is possible, something more horrible about the US military plotting the use of this protonapalm, these glorified petrol bombs. The planners carefully researched, for instance, the construction of Japanese homes to ensure the maximum destruction of civilian lives and property. The programme made heart rending listening - as the fate of Vietnam made a mockery of the post war cries of "Never again".

In the Patrick's Day fuss last week this column overlooked a terrific March 16th programme of Not So Different (RTE Radio 1, Saturdays). Even by the show's usual high standard, this was a fine piece of advocacy radio, advancing without sentiment the position of the families of mentally handicapped people. No euphemisms here: these people are put through the horrors, while 2,700 wait on lists for care services. The 85 year old mother who wonders what will become of her 52 year old son was sadly typical.