In what areas and at what altitudes is 8.33kHz required now? Above FL195?
Practically speaking you need it now for flying around Europe. Someone else will hopefully quote the actual regs.
How often are 8.33kHz frequencies actually used?
Very rarely but there are a few around already.
Maybe I can use a handheld if it’s not too common?
The range is likely to be poor unless wired to a rooftop antenna.
Am I required to have 2 radios with 8.33 capability? Will anyone ever actually check if I have 2 radios with 8.33 spacing?
Only one 8.33 radio is required, despite what many say.
BTW a KX165A/8.33 (the -0201 option I believe is what you want, and somebody is selling one in Classifieds) is a slide-in replacement for a KX155A but not for the KX155 whose tray needs rewiring. Also it is for 28V only.
Lots of people are dumping all Honeywell/King gear due to their latest grab what money you can on your way to the graveyard.
Thank you @Peter. BTW thanks also for your trip reports. I’ve enjoyed them in the past.
Sounds pretty clear I need the 8.33 radio but I’m relieved to hear I don’t need 2. I think I actually have an antenna connector inside the plane for a handheld if it comes to that. I would prefer the KX165A, however. Fortunately my electrical system is 28V.
My COM1 is a GNS 480 so that can’t be upgraded unfortunately.
Mendelssohn are doing a TKM slide in replacement for kx155/165 this summer, not clear if rewire reqd for 155(non A)
We have a TKM thread here.
Despite it being advertised everywhere, the latest info I have is that this product doesn’t exist and is months or years away from being certified. But who knows? So much vapourware in avionics…
It’s crazy… everybody and their dog has known for at least 5 years that anybody who does an 8.33 slide-in KX155 replacement will make a lot of money. And there are a number of players who have all the technology, all certified, and could produce one in a few months.
The logical KX155A (A) replacement is the KX165A/8.33 so that market is less obvious. For example I did exactly that. Net cost about $2500. 5 minutes’ work and a Minor Alteration under FAA, no question.
The TKM replacement looks brilliant, and sounds like it will work in a 155 (non-A) panel. Recent announcements say it’s coming this summer but I guess we’ll see…
Spoke to TKM briefly today. They tell me they’re getting certification now and timeline is “late summer”. Then he said definitely before the 8.33 deadline.
How often do you guys get 8.33kHz spacing freqs assigned in practice? And before the deadline can I just tell them I can’t accept a frequency if I don’t have the radio yet? I’d like to wait for the TKM to be ready.
How often do you guys get 8.33kHz spacing freqs assigned in practice?
It is very rare to get 8.33 and seemingly almost nonexistent for VFR.
I have had it from Dutch Military which is a VFR+IFR unit although it wasn’t clear whether this was only for IFR traffic.
I have had it a few times under IFR, in Switzerland and around there.
So it doesn’t appear to be a practical issue, currently.
I’d like to wait for the TKM to be ready.
You may wish to consider the track record of new avionics 
But with a Garmin 480, you will have a second radio anyway. That is a very nice box, way ahead of its time, which many say has not been exceeded until the Avidyne IFD540 came out. However European IFR flying is a mostly simple point to point exercise… my KLN94 does everything needed.
Peter wrote:
It is very rare to get 8.33 and seemingly almost nonexistent for VFR.
Recently I talked to two guys who flew from Prague to Germany VFR without an 8.33kHz radio. They had a very hard time… at one point they had no other option but to communicate on 121.5… I am not sure if they won’t find an expensive invoice in their mailbox one of these days.
Myself I was in Ceske Budeovice (LKCS) last week (*). Both the airfield itself (which is VFR only!) and the radar frequency for the IFR pickup were 8,33kHz frequencies. So to me it seems that Czech Republic is getting inaccessible without a modern radio.
( * ) side note: Very nice airfield, very nice people, nice town, good food – and beer probably as well as it is the home of the real “Budweiser” – but I had to fly home in the evening and couldn’t find out for myself. But not the place to try and fly a selfmade GPS approach without being very familiar with the surroundings!
what_next wrote:
Recently I talked to two guys who flew from Prague to Germany VFR without an 8.33kHz radio. They had a very hard time… at one point they had no other option but to communicate on 121.5… I am not sure if they won’t find an expensive invoice in their mailbox one of these days.
Wow. So it’s required below FL195 now? Everything seemingly official that I read seems to indicate otherwise.
what_next wrote:
So to me it seems that Czech Republic is getting inaccessible without a modern radio.
Yes indeed, there has been a major revamp of the frequency allocation table here. However, I just looked at a couple of dozen random aerodromes in the VFR manual, and most 8.33 kHz frequencies coincide with the 25 kHz channels (that is, they are xxx.×05, xxx.×30, xxx.×55 or xxx.×80, for which you can tune to xxx.×00, xxx.×25, xxx.×50 and xxx.×75 and no one will notice). In particular, LKCS is 135.930 = 135.925, and Prague Information sector West is still 126.100.
Among those outside the 25 kHz grid are LKLT Letňany (important, the major GA hub of Prague), LKTC Točna (another GA airfield within the Prague city limits), LKMB Mladá Boleslav (fairly important, too), LKPS Plasy, TOWER, GROUND, DELIVERY, ATIS and one of the RADAR frequencies at LKPR Prague-Ruzyně, and ATIS at LKTB Brno-Tuřany. The regional FIS frequencies all remain on the 25 kHz grid.
