That isn’t reasonable, if EMCON is the reason then they won’t give APG-81 electronic attack ability. Beside, you are compare apple to orange, US F-16, A-10, AV-8B don’t have internal jammer because they don’t have to pay a lot of attention to RCS unlike stealth aircraft, and external pods are more flexible, you will also noitice that A-10, F-16, AV-8B don’t have internal forward looking infrared or missile warning system and as we know they carry missiles/bombs externally as well.

APG-81 is already there, so why not use it. For example for SEAD, to clear a path or to clear the way for attacking air defence sites.
For the rest, I don’t think it’s unreasonable to assume that back in the day, it was assumed passive reactions if picked up by air defence gives better chance of survival than trying to battle it out with jamming. Passive reactions include manoeuvring to present lowest RCS towards hostile radars. Or simply running away. Specs were defined some 2 plus decades ago, things change during that timeframe. Hell that’s basically the normal lifespan of a fighter. Not to forget cost was always an issue.
Another reason why legacy jets don’t have internal jammers is they weren’t required to have one, internal or external. Requirements change.

Every jammers contain not only TWT and transmitter but also processor, memory cards, receiver, RF converter and they are designed to protect target with RCS 1000 times bigger than F-35. We know ASQ-239 has processor, techniques generator , receivers, because it can analyze signal and generate optimum jamming pulse to be used by APG-81 and ALE-70. The difference between a hypothetical passive ASQ-239 and an active ASQ-239 is only the TWT, which add a couple of kgs at most given F-35 very low radar signature.

Wiring alone probably adds a couple of kgs.
But sure, if ASQ-239 has active elements or will get them in the future, I’m sure they weigh only a couple of kgs and have very low power output. Seriously though, it doesn’t matter. As mentioned, the issue is requirements not technical challenges.

Physics doesn’t care what you think “too good to be true”.

See that’s a perfect reason why active jamming would be unnecessary. Something like BriteCloud is all you need then.

Of course it will look “marketing-y” that the point of advertising video.
Logically, if they wanted to illustrate radar jamming then they would just make the animation the ray from the nose (like in Northrup APG-81 video), no need to super accurate angle

It’s not from the wing antennas either…

They don’t have to specifically mentioned “APG-81” but logicallyif they intended to show ASQ-239 using APG-81/ALE-70 to transmit jamming signal then they would have atleast said that ASQ-239 can perform electronic attack through radar aperture/towed decoy..etc. No such information was mentioned in the video. Animation of ASQ-239 perform jamming is the same as in EPAWSS and DEWS vid, so why the assumption and excuse that it must means something different?

Why the assumptions? Because its not clear. Why don’t they just say jamming thru ASQ-239 transmitters then if it’s so damn obvious? Maybe because it isn’t?

No, i assume that an electronic warfare system that has a threat library and can computing/create jamming waveform for radar/towed decoys to transmit, will also be able to transmit RF waves by its own antenna.

Do you think an F-16 has no threat libraries? Even Austrian Typhoons have threat libraries, yet they don’t have ECM.
Also you assume. That’s my main point. You assume because it’s unclear.

To sum up, i consider ASQ-239 to be an active system because:
1- BAE themselves said it can perform jamming and digital electronic attack.
2- BAE videos shows F-35 perform jamming in the same fashion they did with DEWS and EPAWSS videos
3- ASQ-239 have cognitive jamming technology, which is more advanced than most jamming systems.
4- ASQ-239 is able to computing/create jamming waveform for radar/towed decoys.
5- ASQ-239 has more antennas than many active ECM systems.
6- i haven’t heard of any internal electronic warfare system that can computing/create jamming waveform but at the sametime can’t transmit with their own antenna. ( Falcon edge/IDECM/Spectra/DASS/DEWS/EWPASS.. etc, none have that behavior)

None of that is clear, doesn’t give a definite answer.
5. is because it covers lots of bands and is an integrated ELS.
6. Do those systems transmitt thru their RWR antennas or do they have seperate transmitters? So what if the ASQ-239 itself is passive and others aren’t. Don’t forget it’s an evolution of the F-22s ALR-94, which is an RWR.

And? Do you consider a fuel probe on F-35B an internal or external system?

What matters is it’s not ASQ-239. So it’s not internal to Barracuda if you will.

1. The same period when people thought F-35 didn’t have a fiber optic towed decoy
2.That pod will affect RCS. It called a multi mission pod because you can put many things inside such as 25 mm cannon, dedicated EO sensor similar to DB-110, GaN SUPPORT jammer similar to NGJ. We are talking about self-defense jamming systems.

So maybe in the future we will learn more. My point.
Of course the pod will affect RCS but not like any bolt on pod. The multi mission pod is not the same as the gun pod. It’s based on the outer mold line of the gun pod.

The F-35 Multi Mission Pod is partly based on the OML of
the F-35 Gun Pod and will provide real estate on the F-35,
which can be used to expand the F-35 Special Mission
functionality, by allowing the F-35 to fly Next Generation EW
and ISR systems, such as jammers and EO sensors.

No need to duplicate NGJ, no need to duplicate internal self defense jammer, if you have it.

No they don’t, they didn’t list antennas and transmitters in DEWS brochure and video.

How do you know they don’t, legacy systems wouldn’t be part of any new kit and not from BAE, so it’s unlikely they would include it in their brochure.
https://image.slidesharecdn.com/silenteaglemediabrief-doc-090317134958-phpapp02/95/silent-eagle-media-briefdoc-15-728.jpg

The illustration is the same between ASQ-239, EPAWSS and DEWS. So where is the evidence/indication that they refer to towed decoy and radar in ASQ-239 video but airframe aperture in EWPASS and DEWS video?

There is no evidence for nothing, my point.

Actually, how is that relevant?. If i understand correctly, you quote the original article to shows that because F-35 may not have aft jamming => ASQ-239 is a passive system. But that argument doesn’t hold ground because ALE-70 itself can operate as aft jammer.

If ALE-70 covers 360°, you have 360° coverage afterall, without using ASQ-239.

F-35B didn’t have gun because the lift fan already taken valuable space intended for fuel.
F-35C didn’t have gun because range is more important for carrier aircraft.
what is the benefit of not having transmitters that weight only 0.3-0.4 kg but give you broad band protection, active ECM when pulling high G.

Exactly my point, they don’t have an internal gun because requirements were different. Not because it would be difficult or expensive to have one.
There’s probably a bit more kit required than some transmitter antennas. F.e. AN/ALQ-131 is round about 300 kg. Of course a good part of that comes from it being an external pod. But cerainly a couple of kgs won’t do it.

Is it safe to assume Spectra, DASS and similar EW will make radar and RWR of mother platform near-useless while they are transmitting because of interference ?

Jamming your own systems – is known to have occured. Manufactures probably don’t like to talk about it. Less of a problem of course if your not transmitting. :very_drunk:

This is such a no brain discussion. If they can put a receiver, a transmitter and a signal analyzer inside ALE-50 decoy then they can put the same electronic parts inside the F-35 airframe without any trouble. We aren’t in the 60s anymore
Note: two decoy inside the launcher

The question is not if they can. Sure they can. They also could have included an internal gun in B/C models. Yet they didn’t.
The question is if they wanted ASQ-239 to be an active system (outside of APG-81/ALE-70).

Truth is Eagle, IDAS in modern aircraft are about the most classified components in regards to capabilities, algorithms, and modes.

Sure, I agree.

AN/ASQ-239 supports jamming functions, that we know. It uses the APG-81 to perform EW functions (as all sensors on the aircraft are fused in the ICP modules), the brochure does suggest jamming functions independent of the radar. It does make sense, the entire aircraft has embedded apertures to support ID and location of emitters. Compare the size of the arrays to praetorian system, or spectra.

In the end, your asking for definitive proof for capabilities that are classified, the best your going to get is the statements from BaE, and they seem pretty cut and dry “jamming without interfering with radar”.

In the absence of definitve proof, I simply assume it doesn’t have the capabilities, rather than assuming it does this and that in addition to what’s known. 😉

They literally shows adversary radar sweeping, then the ray from F-35 wing aperture neutralize that. What else could that be if not to illustrate jamming?. Unless you think it illustrate some sort of EMP, there is really no other “thing”.

APG-81 has a FoV of 120 degrees has it not. Never mind the rays coming from the center of the aircraft, neither system’s antennas are located there. APG-81 in the nose obviously, ASQ-239 in the wing leading edges.

They didn’t say any where in their brochure that jamming must be perform through APG-81. It safe to assume that it can operate like any other internal jamming system that came before, can transmit from its own apertures.

Not only APG-81 but also ALE-70. Note they don’t say jamming must performed with -239 either, but “give pilots the option to evade, engage, counter or jam threats.”
The reason it can’t operate like any other internal jammer might be because it isn’t an internal jammer.

The question is why. There is liteally no reason for USAF to limit the FoV of ASQ-239

FoV is 360 degrees. Using the radar as a jammer is an afterthought imho, not part of the original requirements.
As to why, same reason the AN/ALR-94 (on which the -239 is based) is passive, active ECM was deemed unnecessary for stealth aircraft.

You are really just reading what you want to believe now. It is literally right there

My bad, don’t know how I missed that…
Anyway, jamming without interfering can be done with ALE-70 or multitasking with AGP-81.

I don’t understand the logic here.For example Rafale spectra have about 8 antennas and thought to be fully capable of receive and transmit jamming, yet ASQ-239 with 10 aperture is inadequate for the same task.

I was referring to LRUs/black boxes (though they are actually light gray). The EPAWSS video shows the components at 1:15, among them active stuff like transmitters. Maybe that stuff is all integrated into fewer boxes (Rack 2A/2B) for the -239, but maybe it doesn’t have transmitting components at all.

Firstly, he said may-may not. That what people say when they don’t want to disclose much information. Most people weren’t aware that F-35 can carry fiber optic towed decoy until ALE-70 showed up.
Secondly, ASQ-239 is self defense system. The out put when it transmit from its own aperture won’t reach that of ALQ-99. So may be in aft sector, ASQ-239 is only a defensive electronic system. But in front sector, with the much bigger APG-81 aperture, it can also operate as standoff surpress escort jamming

May = aircraft with 360° jammers, now or in the future (could include F-35)
May not = aircraft without 360° jammers (like F-22, F-35, B-2?)
Boeing is probably aware about what systems were required and are therefore included. Unless requirements were added after they lost?

Here’s a nice graphic:
[ATTACH=CONFIG]260923[/ATTACH]
Note how it says Radar Warnign System – 360° coverage and refers to the 10 ASQ-239 antennas as radar warning or emitter locating antennas. Both sound passive to me.
Whereas the ESM beacon is coming from the radar with its 120° FoV.

About the AN/ASQ-239. It was SpudmanWP himself who mentioned it’s passive only but with growth potential for active components. I think here but also on f-16.net
Of course later in the thread the speculations began, but those are just that… speculations.

It says here:

…the AN/ASQ-239 Barracuda Passive Radar System (PRS), developed by BAE Systems that provides sensor fusion of RF and IR tracking functions and includes data links that form part of the Northrop Grumman-developed Communications, Navigation and Intelligence (CNI) suite.

The PRS provides basic radar warning, and multispectral countermeasures for self-defense against threat missiles, situational awareness and high-sensitivity electronic surveillance. Sensors are placed at 10 locations: on the wings’ leading edges (6), trailing edges (2), and on the horizontal stabilizer’s trailing edges (2).

Future development of the EW suite is expected to address an integrated network and exploitation functions.

From here, original source no longer available?

The F-35 EW system provides radar warning [enhanced to provide analysis, identification and tracing of emitting radars] and multispectral countermeasures for self-defence against both radar and infrared guided threats. In addition to these capabilities, it is also capable of electronic surveillance, including geo-location of radars. This allows the F-35 to evade, jam, or attack them, either autonomously or as part of a networked effort. The enhanced capabilities of the ASQ-239 [and integration with the F-35’s other systems] allow it to perform SIGINT [signals intelligence] electronic collection. The aircraft‘s stealth capabilities make it possible for an F-35 to undertake passive detection and SIGINT while operating closer to an emitter with less vulnerability. For the use of active deception jamming, the F-35‘s stealth design also allows false target generation and range-gate stealing with less use of power.

The EW system also sends and receives data and status and warning information from other onboard systems through the MADL data link.

The ASQ-239 has ten dedicated apertures, six on the wing leading edge, two on the trailing edge, and two on the horizontal stabilizer trailing edge. The system also has the potential to use the F-35’s other apertures, most notably that associated with its APG-81 AESA [active electronically scanned array] radar. In addition to functioning with the radar, this array, transmitting only at high-power, could function as a stand-off jammer

It’s called Passive Radar System for a reason I guess…
Without a source clearly stating ASQ-239 has active components besides towed decoys and APG-81, I think we should assume it doesn’t have them.