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PART NUMBER FOR "SUPER VARACTOR DIODE"
- Thread starter unit_399
- Start date
Okay, so this design is 16 years out of date, but Limor posted all design details for this phone jammer. Don't think it will affect 4G, since it wasn't implemented yet at the time.
http://ladyada.net/portfolio/2006/index.html To date, this is the only set if build-it-yourself plans I have seen for such a device. 73
http://ladyada.net/portfolio/2006/index.html To date, this is the only set if build-it-yourself plans I have seen for such a device. 73
Self tuning??? That must translate to broadband, unfiltered, and capable of jamming anything they didn't anticipate being in use back then...
Keep in mind that jammers, being illegal, have no quality control, and if it interferes with medical equipment or businesses big enough to lobby congressmen, a murder charge or a six figure fine could be in your future.
That said, this is what you do.... find a noise source for that band (commonly available for testing applications) and a suitable amplifier. Everything needed to build a jammer is available as modules that can be easily bought and connected via SMA adapters.
One time (long ago in the 802.11g days) I made a square wave oscillator using a schmidt trigger (at around 40MHz i think) and I had placed a little DC motor with an aluminum fan blade on it next to the circuit so the parasitics caused by the fan blade moving by the circuit modulated the oscillator. Although my intent was to just watch it on the scope hoping to see a sweeping frequency, it killed my wifi instantly. I can't remember what schmidt trigger I used, but it was either fast enough to have GHz harmonic content or something on the board was acting as a resonant circuit, not sure. It was sure interesting at the time though!
But charging over $3k for a "jammer gun", now that's just laughable. Not a chance in hell... Especially when it has a ridiculous Bushnell scope on it as if the multi-band (probably log periodic) beam antenna inside the gun actually had less than a 30° beam angle... Nope, not buying it, even if I had a legit need and the money to waste lol. Not to mention that 80w from a handheld device like that will kill even the best drone-style HVLi battery in a few minutes...
Hahah. Wow.. We have derailed the hell out of this thread, haven't we? I was just kidding on the drone jammer gun. I was being rediculous, in response to the comments about crashing RC planes with radios..
Back on the "super-clarifier-diode" topic:
I did receive my "SLIDER DIODES - Pkg of 5 For CB/10 Meter Radios QRP PLL Tuning VARACAP Clarifier" from Six-Star electronics on Ebay. Shipping took less than 2 days from click-to-mailbox.. Impressive..
However, I was disapointed with the range/performance of these varactors. In a typical 0v-8v or 0v-9v tuning circuit, they have about half the capacitance range of a Motorola MV1404 and about 2/3 the range of an NTE611.. They do have about twice the range of a typical varactor used in a CB clarifier circuit from the factory, but they are a FAR CRY from the "super-clarifier-diodes" of yesteryear.
That said, I'm sure I'll use them for something and for the price & convenience of availability, hey.. I'm not complaining. Be sure and check out the seller's (6-star) "other items" as well. They sell some really neat stuff for radio tinkering & upgrades..
I did receive my "SLIDER DIODES - Pkg of 5 For CB/10 Meter Radios QRP PLL Tuning VARACAP Clarifier" from Six-Star electronics on Ebay. Shipping took less than 2 days from click-to-mailbox.. Impressive..
However, I was disapointed with the range/performance of these varactors. In a typical 0v-8v or 0v-9v tuning circuit, they have about half the capacitance range of a Motorola MV1404 and about 2/3 the range of an NTE611.. They do have about twice the range of a typical varactor used in a CB clarifier circuit from the factory, but they are a FAR CRY from the "super-clarifier-diodes" of yesteryear.
That said, I'm sure I'll use them for something and for the price & convenience of availability, hey.. I'm not complaining. Be sure and check out the seller's (6-star) "other items" as well. They sell some really neat stuff for radio tinkering & upgrades..
Well, sorry I blew up then. You wouldn't want your mint cobra 2000 falling out of the sky. When you take this hobby beyond a microphone, comments like that are received differently.
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You could do a lot of things but remember: To increase the tuning range, we want to increase the difference in capacitance across the range of voltage adjustment (~8V at one end, to negligible voltage at the other). When you place the two varactors in parallel, you are doubling the capacitance across the entire range. This would be fine if the varactors would go all the way to 0 capacitance. They don't. They have a lower range value. So by doubling, in effect, you are pushing the entire range of adjustment lower. This may be fine, as long as you don't mind "tuning down" from channels to get to desired frequencies. But, it's possible to move the whole range so far "south" that you can't even get to the base channel frequency. Increasing the supply voltage to the potentiometer end of the circuit does push things back "north" but not nearly enough and you can't go too high on the voltage without causing other problems within the circuit.
Interesting how this gets mentioned.
Galaxy, at least in their EARLY years, did use 2 diodes along with and RF Switch (D33) to offset the downward forcing...
When you went to Channels below - Like BAND A and BAND B - C92 was used to pull down the tuning range D30 (additional) and D94 (Series-Lo-pass ripple filter SEE:AN612) - when the system needed to push up the tuning range - Bands C, D, and E - it was grounded out enabling it to work in PARALLEL with the Varactors output to help with linearity of the tuning range in the band to help out the PLL's incessant desire to "twang" - in specific instances of weak regulation and drift - when the PLL and the VCO loop on occasion would struggle to match and lock in -this helps offset the needed (or not needed) capacitance to "swing" the channels in the selected Band.
Galaxy, at least in their EARLY years, did use 2 diodes along with and RF Switch (D33) to offset the downward forcing...
When you went to Channels below - Like BAND A and BAND B - C92 was used to pull down the tuning range D30 (additional) and D94 (Series-Lo-pass ripple filter SEE:AN612) - when the system needed to push up the tuning range - Bands C, D, and E - it was grounded out enabling it to work in PARALLEL with the Varactors output to help with linearity of the tuning range in the band to help out the PLL's incessant desire to "twang" - in specific instances of weak regulation and drift - when the PLL and the VCO loop on occasion would struggle to match and lock in -this helps offset the needed (or not needed) capacitance to "swing" the channels in the selected Band.
Awesome post, Andy.. Well, that's bordering on the limits of my analog circuit theory to try to fully understand everything that's going on there.. It's intriguing nonetheless.. I wonder if it would be possible to produce that circuit on a tiny pcb using all smt components for the purpose of a "drop-in" solution for clarifier mods.
The only thing would need to be - is to match the loop frequency of the Carrier oscillator - that 5.12MHz "secondary clock" that 10.240 is halved into.
Then the matching is simply the parsing - start with the base - then divide by two - and hope like h*ll the coils will allow the loop to the range or extent of the spread you want. (That is if you're into Cobra 29's, 25's or the PC series of 66/68 and 76/78 series.
So, in the SSB realm they changed the samplers
Transmission1.net has (or had) something like this endeavor for trying to make the clarifier undriftable. But the problem then lies in the base clock you reference to - being the original 10.240MHz - which - if it drifts, the means to undo that drift depends on the clock references used - ad infinitum ad nauseum.
So in a way, you kind of have to see what others did to offset such a wide bandwidth - so to see the RF switch used in one fashion to work like a ripple filter (slow down) and then paralleled across - to narrow down the rather wide influence was a unique approach to handle the bandwidth, but could NOT offset the drift due to the tolerance issues it requires in free-item or parts as discrete and their package outlines.
So to bring up SMD - it may help but to make it a drop in is not an easy task for say the Cobra 148 uses 7.8MHz and a Tripler while the Cobra 146 (Uniden style) uses a 10.69x with no Tripler - and you still have the drifting amongst the analog realm - so when your PTC or NTC or just plain NOS because you use NPO - you still in a realm of some that act like POS - even though much of the tolerances of the SMD have improved.
I only mentioned the "dual varactor" because of all its faults, has earned the respect of and the distaste for, some that have worked over analog versions of what is now integrated technology
Then the matching is simply the parsing - start with the base - then divide by two - and hope like h*ll the coils will allow the loop to the range or extent of the spread you want. (That is if you're into Cobra 29's, 25's or the PC series of 66/68 and 76/78 series.
So, in the SSB realm they changed the samplers
Transmission1.net has (or had) something like this endeavor for trying to make the clarifier undriftable. But the problem then lies in the base clock you reference to - being the original 10.240MHz - which - if it drifts, the means to undo that drift depends on the clock references used - ad infinitum ad nauseum.
So in a way, you kind of have to see what others did to offset such a wide bandwidth - so to see the RF switch used in one fashion to work like a ripple filter (slow down) and then paralleled across - to narrow down the rather wide influence was a unique approach to handle the bandwidth, but could NOT offset the drift due to the tolerance issues it requires in free-item or parts as discrete and their package outlines.
So to bring up SMD - it may help but to make it a drop in is not an easy task for say the Cobra 148 uses 7.8MHz and a Tripler while the Cobra 146 (Uniden style) uses a 10.69x with no Tripler - and you still have the drifting amongst the analog realm - so when your PTC or NTC or just plain NOS because you use NPO - you still in a realm of some that act like POS - even though much of the tolerances of the SMD have improved.
I only mentioned the "dual varactor" because of all its faults, has earned the respect of and the distaste for, some that have worked over analog versions of what is now integrated technology
Yeah..In the end (in this day & age)if what your into is truly range & accuracy, you might as well just rip out the analog crap and drop in a DDS VFO that incorporates an encoder wheel for fine adjustment..
I remembered that I wrote down the Super Diode numbers years ago when I used to fiddle with them. These diodes can get pretty wild with slide!
Hope this helps:
MV1620 (for 148GTL and similar)
ECG 610 thru ECG 614
(FYI: ECG was sold to NTE)
Cross references:
MV1620: 1S2147, ECG610, NTE610,
MV1624: 1S1923, 1S1923A, ECG611
MV1628, MV1401, 1S1924, 1S2085A, 1S2088A
MV1634: MV1410A, BA102A, ECG613
MV1638: 1S2197, BA102C, ECG614
Hope this helps:
MV1620 (for 148GTL and similar)
ECG 610 thru ECG 614
(FYI: ECG was sold to NTE)
Cross references:
MV1620: 1S2147, ECG610, NTE610,
MV1624: 1S1923, 1S1923A, ECG611
MV1628, MV1401, 1S1924, 1S2085A, 1S2088A
MV1634: MV1410A, BA102A, ECG613
MV1638: 1S2197, BA102C, ECG614
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Here are the specs on those.. Has anyone tried an ECG618? That thing has a 15.5 tuning ratio vs 2.9-3.2 on the ECG611-ECG614 respectively..
I may have tried the ECG618, but I'd have to dust off my old books and look at my notes. It's been years.
I remember buying several different ECG-brand varactors to try on my 148GTL and Grant-XL and one of them was swinging something like a channel and a half (15+), so I took it out. Anything over 10 is overkill as that drops you into the next channel.
I remember buying several different ECG-brand varactors to try on my 148GTL and Grant-XL and one of them was swinging something like a channel and a half (15+), so I took it out. Anything over 10 is overkill as that drops you into the next channel.