From Jack Detsch at Russia Insider:

The Pentagon’s in-house tech incubator is trying to stop Russia from scrambling US battlefield signals in Syria, federal contract documents show…

In April, NBC News reported that the Russian military had jammed GPS signals to US drones in Syria, a technique first honed in Ukraine…

Since entering the conflict in 2015, Russia has rotated “everybody who’s anybody” in the military through Syria, said CNA’s Bendett. Valery Gerasimov, who leads Moscow’s armed forces, has described the Syrian battlefield as a preview for future wars. That includes ingraining electronic warfare (EW) into military training.

From the comments:

As an electronics professional, I will state the U.S. will deal with this problem about the time Russia has arrived with new techniques, based on entirely new principles, and we will be left short again.
We had traitors turn over our secure communications system, from control box to computer, and the same with the Interrogation, Friend or Foe, IFF, also encrypted, and completely turned over, in about 68, yet I was teaching both systems in 94 and 95, along with the “replacement” system which was probably not beyond Russia’s reach, by my estimation, not knowledge.
The great difficulty is one generally learns from current technology, improves it, and having done enough “upgrades”, builds a new system, with the best features, many not on upgrades, but based on same design theory and the like, and are easily followed by an enemy who has come to understand your old system.
Now I’ve been retired for twenty odd years, so I don’t know what they’re using today, but if they haven’t changed their ways, they are using what I left, because the cost of fighting wars has kept us from building aircraft for lack of money, we can’t train pilots, except when an aircraft is repaired, and can be used for a short time, to keep pilots qualified.
When a Nation is doing as Russia is, and doing its utmost to stay out of war, be diplomatic, and is fighting only when absolutely necessary, they have money to keep current, and they know they must stay ahead, so invest in new technology. We established “mag-lev rail”, but we’ve never used it to any significant degree because we’ve been at constant war, and can’t even afford to make them work on the newest carrier, where “steam isn’t an option”, and they still don’t have the “mag-lev rail launchers” fully functional, able to even fulfill war games, much less war.
I’d much rather the U.S. return home and focus on learning our constitution, (not the soldiers, they know it well), learn how to be citizens, learn how to tell lies from truth, and maybe learn how to work again, we seem to have a problem with that. Maybe doing away with food stamps and all the other illegal government largess would allow us to have a budget, pay back our debt, and become a rational reasonable Nation for a change.
Semper Fidelis,
John McClain
GySgt, USMC, ret.
Vanceboro, NC, USA

We developed a system for “Identification, Friend or Foe” in the forties, using special mixed frequencies, at radar bands, and were fairly successful. We developed a system using algorithms to produce a “factor” which could change twice a day, and provide an infinite variety of “factors”, and this concept was used for scrambling voice, and for providing a digital radar signature to identify.
When two Navy brothers, and their respective sons, gave the secrets to the Soviets, in 68 time frame, the Soviets had recovered downed systems from the Vietnamese, and given full schematics, wiring diagrams for aircraft, and having recorded every electronic emission we put out, they were able to passively watch our every effort, and know specific identity of aircraft and pilots, and translate every word of coordination. From this they filled in the blanks on our weapons and tactics, and our next generation communications security and Identification, Friend or Foe, had been designed off the principles of the previous, so it was obsolete before production. We operated from 70, to the late nineties, with no com security, and no means of using IFF, with any confidence at all, and given the fact, we were totally prepared to launch next generation when we discovered how deeply we’d been exposed, we lived essentially without such systems for two decades.
The original idea that established our actual security, was a “epiphany”, an idea straight out of the blue, and thus almost impossible to reverse engineer solely from signal interception. Unless the system now in place is equally “epiphany generated”, it is likely there is sufficient connection to other electronics means, it could be compromised already.

We entered the second world war with a “war department”, and a mindset of defending Nation by war. Liberal thinking chose to come out of that war and make it a “defense department”, not because it would be, but because top leadership had already decided it would proactively prevent war with war, and renaming the department would fool many into believing the stories that would proceed.
Those who choose “preemptive war” for defense, seldom count the cost of “using up munitions” as taking away funding from actual defense spending on research and development, and when they run into a wall, they alter the fiscal system, not the cause. Those who might have pursued careers for actual defense, delving deep in science, are often dissuaded, and go into peaceable careers, and many inventions are never patented because principles belong to individual people, who live or die by them, and they won’t give their work to evil purpose.
Russia has had the best available testing grounds for all their systems, in our never ending wars, watching their weapons used in other hands, and seeing weak spots, or areas of improvement, available. They know none of their systems are perfect, but they don’t appear to wish to rule the world, and so they are very careful who they support, who they stand with, morally, and who isn’t trustworthy, and while they lost an IL-20 out of trust this time, it has changed the paradigm, and caused the advent of much more challenging field of battle.
We, on the other hand, have our hands full trying to reach any conclusion to Iraq or Afghanistan, we have nothing but bombs and military units, and neither will change the fact we’ve ensured we are hated by all parties, yet our politics won’t let us just walk away.

We can’t build F-35’s, except with other people’s money, we can’t maintain F-18’s, too many hours in half their intended lifespan, same with 15’s and 16’s, we never built anywhere near enough F-22’s, war is more expensive than aircraft, and they cost like ships. We’ve gotten lots of experience flying in “the most hostile electronics environment ever”, with two generation back aircraft, pilots with far less time in flight than should have, and at the same time, Russia watches others fly their birds, and learn, they both live in this “hostile electronics environment”, and are in large, a cause of much of the deliberate jamming, honing their skills, seeing weak points in their systems, taking note, and what they build, bring profit, because they are selling to our enemies, for defense.
We sat in that chair, sort of, during the first post-war years, but our leaders chose to control the world’s war future by preemptive war tactics, rather than bother with diplomacy and reason, so we shortly lost the advantage of watching our equipment used, without expending our own monies, replacing downed and destroyed materiel.
When the Soviet Union broke up, took a break, and began pillaging Russia, and enticing former soviet states to western allies, and to do so, we had to fall into war, and preemptive war means expending the munitions.
We had scheduled the V-22 Osprey to replace the CH-46 by 84, and stopped funding 46 maintenance and repair of aircraft specific parts. It was two decades later before the first V-22 squadron was up, and in the mean time, we stripped every usable part from every 46 to be found, world wide, just to keep up our duties, with the last of them all having at least one “body panel” with patched holes from Vietnam bullets, having been rescued from the bone yard.
Our fascist form of government can’t operate rationally, and it can’t be economical, because it’s not assembled from the “best of the best”, but from “the worst of the worst”, in ideology, and such people don’t want the details, “don’t come to me again till you have succeeded” is their mentality.
Russian equipment is built and designed to serve its purpose, and they don’t have 1000 bases around the world, a military they can’t afford, yet keep it occupied expending money despite not having any.

Lots of people have denigrated “capitalism” as a decadent western venture, but we’ve taught the world, its a natural law, it can’t be evaded, and it controls what one can do. We did so by having capitalized everything, we turned to fiat currency “for the depression”, never turned back, and have increased our spending as we’ve reduced our income, and we stopped capitalizing business, and now, fifty years later, we have to import the things we invented. We flew our “last shuttle mission” because the infrastructure left over that was used to build shuttles, finally wore out. We stopped sending rockets, really big ones up, because we let that industry die, for lack of capital.
Nations come into being because people take raw material, add labor, and make something desirable to others, and get paid for the work. This is capitalism, and when it made spears, bows and arrows, and shields, one still needed to husband resources, needed to decide whether this fight need be fought, or could be avoided by diplomatic effort, and because we realized cost, by the fatigue in our muscles, we did so.
Governments are so far removed from real cost, it is easy for them to lose any ability to accurately assess situations at any level, when they’ve been without cause long enough to forget the complexities of “compound interest”, and the down side.
Semper Fidelis,
John McClain

From Wikipedia:

Walker began spying for the Soviets in late 1967,^[8][9] when, distraught over his financial difficulties, he walked into the old Soviet embassy in Washington, D.C., sold a top secret document (a radio cipher card) for several thousand dollars, and negotiated an ongoing salary of $500 to $1,000 a week…

In 1990, The New York Times journalist John J. O’Connor reported, “It’s been estimated by some intelligence experts that Mr. Walker provided enough code-data information to alter significantly the balance of power between Russia and the United States”.