Why wasn't the RADAR ever updated?

[PhantomHans]

So, I just have to ask, why wasn't the radar ever updated by most end users?

If I understand correctly, the F-4J and S got a pulse doppler radar.  But the F-4B,C,D,E,F,G, and N, other than those few later updated with modern radar by foreign users, did not get any updates.

 

As a side note, I understand the B,C,D, and N had a different radar than the APQ-120 but other than perhaps longer range due to the bigger dish I understand it to be quite similar?

I have no idea what the British F-4K/M had.

Seems kinda odd to me though as the radar is the one part of the jet that, at times, really seems to be lacking and hasn't been improved by the time of our E model.

[Ivandrov]

I'll talk mostly within the scope of the F-4E. But, usually the primary reason is money.

 

To be clear. The APQ-120 was actually upgraded, up to a v9, I believe.

But, given a certain budget, you can spend that money upgrading old airframes to fit the new radars (It's not just a matter of swapping dishes, often the radar is designed to fit the airframe not only in terms of size but things like power draw, and the weapons control systems) or you can just shove the new tech into a new airframe.

 

Of course, you have to realize that these are old airframes that might be reaching retirement anyway, with increasing maintenance costs.

 

The ones who continued to update the old airframes are usually the ones that can't really confidently meet the upfront cost of new ones. So, you're only left with the option of upgrade.

Edited Monday at 01:47 AM by Ivandrov

[PhantomHans]

I figured a large part of it had to be cost.  Thing is, with the F-4 still being a major component of western air forces until 1990 (or even beyond) it seems like an APQ-120 replacement to give modern pulse doppler capabilities, even if at the cost of reduced range or horizontal scan volume for example, would have been a huge hit.

[Ivandrov]

4 hours ago, PhantomHans said:

I figured a large part of it had to be cost.  Thing is, with the F-4 still being a major component of western air forces until 1990 (or even beyond) it seems like an APQ-120 replacement to give modern pulse doppler capabilities, even if at the cost of reduced range or horizontal scan volume for example, would have been a huge hit.

Huge hit to money spent elsewhere, probably. Especially if we're talking post cold-war where the mindset became reducing the sizes and budgeting to military. There's certainly a priority list when it comes to this stuff and trying to convince people to upgrade old airframes when their first thought in their heads is, "Man, this thing is old, gotta find a replacement." Is extremely difficult.

[Cytarabine]

Several users who held onto their F-4’s into the 90’s and early 2000’s did modernise the radar with a new set, however by then in US service the Phantom was on the way out.

I guess it would be cool to have one of those variants, though to be honest we would end up destroying some of the charm of the current module with how challenging the radar is compared to more modern jets. 

[PhantomHans]

4 hours ago, Ivandrov said:

Especially if we're talking post cold-war

Ahhh see I was thinking during the cold war.  Like a late 1970s or early 1980s update just to get pulse doppler retrofitted.  Even if the set couldn't do TWS, had a shorter range, or smaller scan volume, pulse doppler seems like it would be so much more capable particularly in the low level ground attack role the F-4 found itself in.  Make it more able to defend itself.

By 1991 it doesn't make sense to me to upgrade it unless you just can't afford anything else.

But yes I guess money isn't unlimited.

[SuperKermit]

vor 6 Stunden schrieb PhantomHans:

Ahhh see I was thinking during the cold war.  Like a late 1970s or early 1980s update just to get pulse doppler retrofitted. 

Keep in mind that the F-15A started being implemented already in 1976 taking over the A2A role of the F-4 in US service. So why spend money on something you don’t need?

Edited 32 minutes ago by SuperKermit