Stryker's "Uparmored Receiver" feature ??

[BOOTY MONSTER]

how does this work , or rather .... does it really work ?
can something like it be added to cb radios or other exports ?

i know its supposed to protect a radio from being damaged by a very close or very strong signal . there's a guy here that says hes had 3 radios burnt up by a guy less than 2 blocks away running over 5000 watts with a beam . i was wondering if something like the uparmor could be added to his radio or if he should maybe get a stryker radio ...... if its really an effective feature .

i have noticed ive never had a car stereo damaged even when in the parking lot of a fm station broadcasting tens of thousands of watts if not over 100k , same thing with living near a tv station .

 

[Captain Kilowatt]

I have no idea what "uparmored" is or how it is done but two simple signal diodes back to back across the receiver's front end will do wonders for preventing damage due to overload.

 

[Robb]

Interesting point...

Not that I have the answer to your question, because I don't. Commercial FM broadcast stations won't have 'bleedover' problems, as I'm pretty certain that they must have enough filtering to assure they are where they are supposed to be due to FCC regs - bandwidth-wise. Pretty sure that FM receivers in our cars/home aren't made to be as sensitive as our kind of radio gear is.

Since our CB/Ham radios are built to be very sensitive - mere microvolts give us S-unit readings. Not to mention that many Ham radios have preamps to amplify these very weak electrical signals even further.

Having said that, with as much energy coming from a 5,000 watt station that close to a radio that is built to be very sensitive with minute power changes, fundamental overload might be able to damage a receiver.

I've also heard stories - 'anecdotal evidence' - of receivers being blown out by stations that don't even run that much power. The use of Shottky diodes can also lend to such a situation. Indeed, there are mods available for the Ranger TR-696 found on the Defpom page that will give the receiver a great boost that I've read about. But a warning came with it, saying that damage may occur if a strong signal may be present.

Just some thoughts.
Looking forward for some replies and info from this thread...

 

[JustinDePolis]

Guys, that's exactly what the feature is. RF coupled in the front end with two back to back diodes that will "clamp". I personally added this feature to the design for Stryker in 2005 / 2006.

 

[mechanic]

I have added this to several different short wave receivers to protect the "front end". I have seen as many as six diodes used for this but that is over kill and two will work fine....

 

[Captain Kilowatt]

I have used the two diodes back-back on a few receivers in the past. A friend of mine brought me a dead shortwave receiver one time. I had no problem finding the problem as the frontend FET was split into two pieces. He said that when he disconnected the coax he drew a spark off the cable. For that RX I installed a series capacitor as well as the diodes. He never had another problem. BTW his problem was with static on a really loooooong antenna.

As for sheer frontend overload from a commercial station, it does happen. If I was listening to the 10 Kw AM station I had to service when I drove into the TX site the audio would become a bit distorted and the 920 KHz signal could be heard over half of the band and nothing was heard on the other half.

On the FM band, if I was listening to the 100Kw signal, my car radio would go dead as I drove into the FM site when I was about 6-700 feet away and then come back again if I parked right at the base of the tower. The base of the tower was in a deep signal null. Both cases of overload have nothing to do with regulations or purity of the TX'ed signal and have everything to do with the RX's ability to handle strong signals.

The only time I have heard of a ham RX being blown out by too much RF on the front end was when my former boss forgot he still had his Kenwood R-1000 connected to the three tower AM array when he flipped the 1 Kw transmitter back on. No amount of protection was going to help in that case. He didn't fair too badley in the end, just a blown bandpass filter coil, a capacitor and the RF amp transistor. Not bad for about 225 VOLTS of pure and direct RF injection.

 

[davegrantsr]

Guys, that's exactly what the feature is. RF coupled in the front end with two back to back diodes that will "clamp". I personally added this feature to the design for Stryker in 2005 / 2006.

well, now we know why an AM/FM stryker with $30 worth of parts sells for $275. still not sure why the S3 labeled radio sells for so much $$ ;-)

does it work? yeah, it does what it's supposed to do, not neccessarily what stryker says it will do. $2 worth of diodes.......

 

[jazzsinger]

well, now we know why an AM/FM stryker with $30 worth of parts sells for $275. still not sure why the S3 labeled radio sells for so much $$ ;-)

does it work? yeah, it does what it's supposed to do, not neccessarily what stryker says it will do. $2 worth of diodes.......

don't you know those are very rare kryptonite diodes,at least $3 worth.

 

[davegrantsr]

don't you know those are very rare kryptonite diodes,at least $3 worth.

those sneaky left-coasters.......

 

[TonyV225]

Im willing to bet that those diodes are exactly what the Doc in "Back To The Future" used in his Flux Capaciror setup in his DMC time machine

 

[JustinDePolis]

It is, the problem is that the boards for the time space continual circuits were made in the same place the RCI / Galaxy boards are, hence in the movie why they had to keep hitting the display for it to come on...

 

[jazzsinger]

It is, the problem is that the boards for the time space continual circuits were made in the same place the RCI / Galaxy boards are, hence in the movie why they had to keep hitting the display for it to come on...

I thought that was a factory installed feature to keep you on your toes whilst dx'ing.