Stryker SR-94HPC Noise Blanker and AMC

[Shockwave]

The pictures below show the 19.2 MHz crystal that was in question.

I've also included the block diagram, which confirms the NB circuit I sent earlier was from the SR-94HPC.

As mentioned before, the schematic is not our intellectual property, and we can't share what we do not own.

Since Stryker Radios has decided to become unresponsive with respect to their non functional NB, that was quietly replaced with a working ANL, this may be the last email sent before formal complaints of false advertising are filed against the company:

Hello Shawn,

It’s been a full week since Stryker Radios was asked to provide any evidence that a noise blanker has been installed in the SR-94HPC. We’ve been told that the company cannot release the schematic because it’s not your property. Yet, 3 days ago you sent me the full schematic for the NB circuit but have been completely unable to provide any follow up information as to where the key part, Q6 is located on the PC board??? Something you said you were going to do. Part of my being somewhat persistent and even rude about this, is the fact I’ve already tried to get Stryker to address defects in this radio years ago and the company didn’t even respond.

So, this time more pressure was applied in a place where other customers who purchased this falsely advertised radio, would see it. When Stryker was incorrectly accused of X1 not being on the PC board, you simply took a picture of the board showing X1 with a red arrow. When it came to the real issue of the missing, functional noise blanker, not so much! What we did learn from that schematic, is confirmation that the falsely advertised NB switch and function, was deceptively and secretly connected to an ANL circuit, with no mention of that fact in any advertising, or the radios incorrectly labeled front panel controls.

When I was wrong about X1 and you asked me to correct that issue in the WWDX forum, you didn’t even give me a chance. For the first time in 14 years, you logged into the forum and did what you should have done with Q6, in the first place. Eager to prove me wrong on something insignificant with respect to the NB problem, you posted the picture with the red arrow pointing to X1 while completely avoiding the fact that you can’t point out a working NB circuit on that PC board and have consistently failed to point out the defective one, you claim is in place. Which, just so happens to be “covered up”, by an unadvertised ANL. That fact alone, screams of intentional deception through false advertising!

Your companies choice to go totally silent after being called out on that in such a way, that you could not explain your actions any longer, speaks more to your intentions, than anything I could say or add at this point. Show us any test that Stryker can use to confirm NB function, or get that falsely advertised function out of your advertising and make the switch say ANL, rather than something you’ve failed to provide paying customers for years. Failure to follow either of these honest solutions to your ongoing problem, is likely to result in a formal complaint of false advertising, being filed against Stryker Radios.

Regards,
Donald.

 

[Shockwave]

Since this radio was purchased for mobile use and totally failed without the advertised NB circuit working, I carelessly put it through some other tests to help explain why it toasted the FQP13N10 finals, with just a quick hot switch of the antenna selector. The radio does "appear" to have High SWR protection to save those finals so, why did it also fail to work as designed? Incidentally, another forum member questioned why his SR-94HPC was displaying "TX ERR", in the chat window a few days ago. I learned last year, that is the symptom the radio displays once the finals short. Yes, "short" and not "open".

To start, lets consider what the manufacturers datasheet has to say about their FQP13N10 MOSFET. They state that it was specifically designed for "DC to DC converter applications". What that means is this part is intended for low frequency use that would usually be measured in Khz. Not High frequency RF measured in MHz. The part was not designed to handle the added stress of being biased into or near class AB, much less being driven by a waveform that transitions between any point, other than a full on or full off condition. Like for example, the pulse width generator that would normally be found driving this part.

Now let's consider what happens when you abuse a power supply transistor by using it as an RF amplifier, in a radio that has near useless VSWR protection. My radio is already on its second pair of finals and they were replaced with the ERF2030+ transistors. They make more power in this radio and draw less current in the process which, automatically equals less heat, through improved efficiency. They also handle the abuse noticeably better, even though they are still likely to be another power supply part.

For VSWR protection to be effective in a radio, it needs to work within microseconds. To get some sense of the maximum amount of time the transistor can handle an overload condition without failure, we can look at the maximum pulse width on the datasheet, provided for the most stressful operating condition. In the case of the FQP13N10, that figure is an absolute maximum of 300 microseconds. Double or triple that time and the chances of failure are likely. What do you think would happen if it were subjected to that overload for more than 3,000 times longer?

While testing the output of the SR-94HPC into both an open and a short condition, guess how long it takes for the microprocessor, to react to the line sections extreme reflected power signal? In every case, I timed just about a full second! Plenty of time to measure reflected power on the analog Bird, see the current spike on the bench supply and the radios digital volt meter drop from 12.6, to 11.0 volts! By the way, all of that voltage drop is in the internal light gauge wiring and light duty DC power cord, permanently attached to this radio.

The microprocessor senses the voltage drop and displays it on the front panel digital meter, long before it inhibits the dangerous operating condition. It literally provides enough time to burn up the stock finals, thousands of times over. While my manual rotary coax switch is slower than your average relay, it does beg the question of, how close does using any external amplifier that hot switches a relay, take these finals towards a failure condition?

Since the VSWR protection is not fast enough to save the finals when they are actually placed into a situation where you need it to work (it's an antenna warning indicator), you may want to upgrade your rig or at least do so if the finals fail in the future. Don't waste your time with any Max Mod series pass modulator transistor. Just change both finals to EFR2030+. DO NOT change the driver or you will have too much stage gain and defeat the added headroom.

 

[Shockwave]

Your request (57015) has been updated. To add additional comments, reply to this email.

This board isn't exclusive to Stryker, nor do we have any reason to mislead anyone. Unlike our other radios, this isn't a board we designed.

Thank you for your time!
Stryker Radio Support

------------------------------------------------------------------------

Shawn,

You say “This board isn't exclusive to Stryker”. That just shows Stryker is comfortable reselling Anytone's falsely advertised product. You go on to say: “nor do we have any reason to mislead anyone”. However, it doesn’t take a rocket scientist to determine that you have been forced to adopt the same reason Anytone had to LIE about this missing and deceptively replaced feature. What you’ve done is called “bait and switch”! By claiming “this isn't a board we designed”, it appears you think Stryker has no responsibility (or has been instructed to avoid it) to every customer they cheated out of an NB circuit and deceptively replaced with ANL, in the Stryker SR-94HPC.

You put your company name on that radio and still continue to sell it under false advertisement! Furthermore, it appears your company is determined to leave their dishonest tactics in place. If you believe your companies lies, do what you can’t and show us where Q6 is on your PC board??? On the other hand, if you’ve learned that your employer has been dishonest by replacing NB with nearly useless ANL, you’ll avoid all responsibility (for now) as though it were China virus. Since both the radio and your company have shown no ability to demonstrate working NB function, your problem will not go away until the falsely advertised NB button, is corrected to reflect the ANL circuit, that has been hidden in its place!

Regards,
Donald.

 

[Shockwave]

The pictures below show the 19.2 MHz crystal that was in question.

I've also included the block diagram, which confirms the NB circuit I sent earlier was from the SR-94HPC.

As mentioned before, the schematic is not our intellectual property, and we can't share what we do not own.

Emailed to Stryker this morning:

Hey Shawn,

After a month of burying your head in the sand regarding your companies noise blanker "Bait", being sold with the ANL "Switch" (bait and switch), you do understand Stryker is not only reaffirming deception through false advertising but, that it's willfully so? You're unable to claim Stryker is unaware of this false advertising now so, you hide. Sorry, I just had to give you another "poke". Something about getting screwed over and lied to, just doesn't sit as well with me, as it may for you or Stryker.

At the very least, our forum members are educated buyers now. You know, the one's you belittled by calling this site the world wide citizens band forum, as we're discussing your defective, or falsely advertised "10 meter amateur radio"? By running away from Q6 as quickly as you did, you've established which of the two, it is. It's worth adding once again, that this is the ONLY place Stryker has been forced to admit, that they are selling a radio, with a switch that says NB, connected to an ANL circuit. EXACTLY what I accused you of, three years ago. Our heads are not stuck in the sand and are now informed, that if we have any requirement for Noise Blanker filtering in order to make decent reception possible, IT WILL NOT BE FOUND IN YOUR SR-94HPC!

Any idea how many of us can't hear a damn thing other than noise with the engine, AC or heater running? Most think it's just a crappy receiver and never even knew it was a missing function. 45,000 of our members and hundreds of thousands of guests, would like to know, what Stryker is going to do in order to end their false advertising and compensate all previous buyers, for getting cheated out of what they paid for through false advertising? Actions speak louder than words, and your inaction, is deafening.

 

[86lidewell]

maybe they have no legs to stand on since this is an anytone radio re-branded.

 

[Shadetree Mechanic]

All they need to do is turn the flaw into a feature. Software programmers do it all the time.

"New and improved noise blanker that functions as ANL."

"Found in no other radio, unique performance gains."

Now it can be a major selling point.....

 

[Handy Andy]

maybe they have no legs to stand on since this is an anytone radio re-branded.

Interesting to see that they DID admit that it (94HPC) is not their radio...

Oh-Boy!

 

[Shockwave]

Saying "it's not our radio" would work just fine to remove liability from Stryker if, they didn't rebadge it with their name and continue selling the falsely advertised product in North America. Either they resold thousands of radios under their brand name without ever checking to see if they had the basic functions being advertised to their customers or, they know and don't care. After 3 years of complaints, any option to claim ignorance has been totally removed today.

I just wanted to make sure customers understood that the receiver is not loaded with noise due to a poorly working noise blanker. The designer knew they had a NB button that did nothing and they couldn't even begin to fool anyone with that. The fix was to secretly install the ANL circuit that costs about 1/25th the price of a NB circuit and to make sure they never advertised a single word about any ANL, while they left the falsely labeled NB button intact too.

Keep in mind the only confirmation from Stryker that this radio had an unadvertised ANL, came as a result of them sending a schematic and block diagram, trying to prove there was any NB on the actual PC board. In doing so, they accidentally removed all doubt that the NB switch was activating ANL control lines. The only motive I can even begin to think of for not advertising this radio as having an ANL filter, is because they intended on misusing it to replace the much more effective and advertised NB filter.

I'm just about certain this is the only radio in history to never mention the fact it came with an ANL. You brag about every single feature your product has unless, you're misusing a cheap one, to cover up for a missing one that is more expensive. The difference between ANL and NB is huge. ANL is a very simple audio filter that can never reduce the noise level on your signal meter and uncover signals hidden under an impulse noise floor.

 

[TM86]

The only motive I can even begin to think of for not advertising this radio as having an ANL filter, is because they intended on misusing it to replace the much more effective and advertised NB filter.

There's always the possibility that they thought their target market was too stupid to know the difference.

 

[Shockwave]

There's always the possibility that they thought their target market was too stupid to know the difference.

Thank you for saying what I was thinking about Stryker. It's not really a matter of being stupid. Smart people that have never seen what they can expect from a real NB, have no way of knowing, without either a deep technical knowledge of the subject, or using a radio that didn't lie about its features, to compare this against.

 

[Handy Andy]

The same could be said about Uniden's

(Yes, I said UNIDEN's)

Being 980 series, let alone the Midlands' 79-290 series - Noise Blanker and Receiver noise - as basic noise, the ACTUAL noise - as Receiver Signal to Noise - with no signal - "White Noise" - is where I draw the line - I have two models - earlier (V1) and the latter (V2) with QUESTIONABLE Noise Blanker operation.

​

IF it was not for the TRC-449 Entry, Realistic, their offer with a NB section that has no peaking coil except for input from the IF strip.

With the main premise being - if it exists, does not mean it works.

Effective, versus actual working circuit - I've seen more vehicles with added accessories that are totally useless for the trim line it is used on, if only to pad the wallets of the sales department...

 

[TM86]

Thank you for saying what I was thinking about Stryker. It's not really a matter of being stupid. Smart people that have never seen what they can expect from a real NB, have no way of knowing, without either a deep technical knowledge of the subject, or using a radio that didn't lie about its features, to compare this against.

You can substitute "ignorant" for "stupid" if it helps any.

They weighed the the risk of being found out vs profit and profit won.

 

[rftek]

It sounds like there are new noise blankers in SDR receivers that are using IF stage noise reduction algorithms. I may be wrong but it sounds like there are no dedicated noise blanker circuit components involved and they are using strickly algorithms.

https://www.rtl-sdr.com/sdr-now-stage-noise-reduction-algorithm/

 

[rftek]

I found a THESIS that explains how to build a RF noise blanker before the signal even enters a receiver.

ELIMINATION OF IMPULSE NOISE FROM COMMUNICATION RECEIVERS
BY THE RF BLANKER METHOD (1962 unclassified and I believe that their are no copy rights).

I think that it would be great if we could make our own noise blanker instead of spending hundreds of dollars for a commercially made ADSP filter. If there are any engineers out their that could help out and get it to work or improve this design it would be great. I uploaded the original article and also cleaned it up so it will print out clearer.

See attached schematic and also the article download links.

Frank

https://drive.google.com/file/d/10gFX07bdNJcdEOccBA8D9ddatmTZH3w8/view?usp=sharing,

https://drive.google.com/file/d/14ndQnI9_izQrKuUHAQh9Z7miVRpcYrFA/view?usp=sharing

 

[nomadradio]

I guess you could say that this thread died.

More like became a zombie.

Some of the contributors to it are still active here, some are not.

73