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Author Topic: Best MWDX antenna?  (Read 53625 times)

Offline RobRich

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Re: Best MWDX antenna?
« Reply #270 on: January 26, 2024, 2356 UTC »
Yep. I figured on picking up an used Acopian, Allen-Bradley, or similar power supply anyway. Lambda works for me. Supposedly NOS as well. Thanks for the link.



The DC blocks arrived. Did a quick test on a SDR. No immediately noticeable insertion loss on MW/HF.

There appears to be a little loss down in lower LW under probably 100KHz, though I did not care enough break out the NanoVNA to measure.

Hardly surprising IMO, as they are inexpensive DC blocks for CATV. Anyway.



Here is an interesting one. My nightstand receiver is basically a small WinARM notebook, an inexpensive MSI SDR, and an active miniwhip.

IIRC, the bias tee probably already has an internal  isolation choke. though I did not bother testing it. Instead I added a mix 73 binoc ferrrite with like 3-4 bifilar turns on the antenna side just in case.

Not bad but still some weak evenly spaced lines in the waterfall. Likely from the notebook and/or SDR. Dropped the PSU, which I already know is somewhat noisy at low frequencies, yet they were still there. Touched the metal case of the SDR, and they mostly disappear. Now I am getting somewhere.

Tried adding a mix 73 binoc ferrite wound as an 1:1 isolation transformer near the SDR. No real help there, so it is not coming from upstream, which is not too surprising if the bias tee likely already has a choke.

Okay, what if it is actually a ground loop or similar causing the issue? I grounded the SDR back to the power strip ground. The issue is now mitigated.

A some point I should get around to moving the feedline to a passive antenna as well, but the nightstand SDR is mostly for background noise, so "whatever" for now.
« Last Edit: January 28, 2024, 0552 UTC by RobRich »
Tampa, FL USA | US Map Grid EL88
Airspy HF+ Discovery | KiwiSDR 2 | 2x Msi2500 Msi001 | 2x RTL-SDR V3 + NE602 | 2x RTL-SDR V4
148' + 60' Loops-on-Ground | 31' Vertical | 18' End-Fed Vertical | PA0NHC MiniWhip

Offline ~SIGINT~

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Re: Best MWDX antenna?
« Reply #271 on: January 28, 2024, 0217 UTC »
Quote
Okay, what if is actually a ground loop or similar causing the issue? I grounded the SDR back to the power strip ground. The issue is now mitigated.

Nasty. I wonder if the enclosure is actually floating (un-grounded)? Do you have an AC line isolation transformer that you can put before the power strip to see if that also removes the noise? I have isolation transformers in front of most of my gear so ground is actually ground and not neutral bonded to ground.

Offline RobRich

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Re: Best MWDX antenna?
« Reply #272 on: January 28, 2024, 0545 UTC »
There is an ESP XG-PCS-15D power filter before the power strip.

Interestingly enough the issue persisted even on battery, and IIRC, the linear power supply feeding the bias tee disconnected . I suspect it is internal to the ~$30 SDR. ;)

https://revspace.nl/Msi2500SDR
https://github.com/EndlessEden/msiSDR/tree/RSP1-S

Mine should be "full" variants since they have the five bandpass inputs and came with enclosures, though I have not directly verified the circuit layout through disassembly. I am not too concerned either way as they are mostly used to casual HF listening. That said it would not surprise me if the PCBs are not effectively grounded to the enclosures.

The RTL-SDR V4 for $30 pretty much makes its older V3 sibling and most of the MSI variants kind of pointless for HF anymore IMO. I have not got around to poking at rtl-sdr-blog drivers on Windows ARM, thus why I have a MSI SDR connected to my nightstand receiver.

Ideally I probably should get my Kenwood R-2000 back on the nightstand. Problem there is needed troubleshooting I have not felt like doing, or I might eventually send it out for repair. I suspect a damaged FET in the first stage.
« Last Edit: January 28, 2024, 0554 UTC by RobRich »
Tampa, FL USA | US Map Grid EL88
Airspy HF+ Discovery | KiwiSDR 2 | 2x Msi2500 Msi001 | 2x RTL-SDR V3 + NE602 | 2x RTL-SDR V4
148' + 60' Loops-on-Ground | 31' Vertical | 18' End-Fed Vertical | PA0NHC MiniWhip

Offline ~SIGINT~

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Re: Best MWDX antenna?
« Reply #273 on: January 28, 2024, 1507 UTC »
I'm glad that I am not the only crazy one with a receiver on my nightstand. That is the home for my ICOM IC-R75 and mini-whip antenna. The antenna is currently inside the house hanging in the window frame. I picked up a "through window" flat cable back in December and plan to move the antenna outside once the weather gets nice again. You probably guessed it, the antenna is powered by a small HP 6216A power supply and the entire AC power path runs through a ONEAC CL1101.5 power conditioner.

The R75 is perfect for this application because the LCD colour is perfect and the brightness is adjustable plus is has a "sleep timer" function. I usually set it to 1 hour then it turns itself off automatically. My BelkaDX and Sony ICF-SW7600 work equally well when travelling.

Offline RobRich

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Re: Best MWDX antenna?
« Reply #274 on: January 31, 2024, 1635 UTC »
Need to check the 31' vertical. Signals are way down. Suppose I will start with inside jumpers and work my way from there. Fun stuff.



Resolved. Appears to either have been the jumper to the KD9SV common-mode choke right outside the house, or it could be the choke itself. I just removed them on both my 31' and 148' loop-on-ground for now.

I probably should replace the chokes with galvanically isolated chokes anyway.



Seller cancelled the 5v power supply order. Oh well.

Ordered a Lambda LCS-CC-5-O with a LHOV-5 over-voltage protector installed. It is way oversized for my purposes at up to 16A capacity, but it was decently priced.

https://www.us.lambda.tdk.com/products/legacy-products/pdf/lc_fall85.pdf
https://www.artisantg.com/info/TDK_Lambda_LMOV_LHOV_Overvoltage_Protectors_Manual_202012135713.pdf
Tampa, FL USA | US Map Grid EL88
Airspy HF+ Discovery | KiwiSDR 2 | 2x Msi2500 Msi001 | 2x RTL-SDR V3 + NE602 | 2x RTL-SDR V4
148' + 60' Loops-on-Ground | 31' Vertical | 18' End-Fed Vertical | PA0NHC MiniWhip

Offline ~SIGINT~

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Re: Best MWDX antenna?
« Reply #275 on: January 31, 2024, 1827 UTC »
Quote
Seller cancelled the 5v power supply order.

Scoop up those power supplies while they are available at reasonable prices and before greedy vendors figure out that there is a potential increase in demand driving up prices.

Offline RobRich

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Re: Best MWDX antenna?
« Reply #276 on: February 01, 2024, 0639 UTC »
Audiophile and SBC enthusiasts have driven up demand for 5v linear power supplies. There are lots of new models from China flooding into the market in recent years. My concern is the specs, or more often like the lack thereof. "Low noise" does not mean much IMO, and reviews can be all over the place as well since parts can change from production run to run.

Anyway, yeah, I am with ya'. At least the older supplies for lab, plc, and other precision uses are typically "known quantities" with often many years of stabilized designs.

The Lambda LCS-CC-5-O I ended up ordering is older and used, but I suppose if it does eventually need work like new caps at least most of the parts are probably through-hole. SMD parts and my hands really do not go well together anymore.

Speaking of linear power supplies, I recently moved my cable modem and network router to one. Probably no real difference, but it eliminated two more switchers.



Seeing as my 31' vertical seems to be doing decent at lower frequencies, I took a skim of VLF frequencies after midnight EDT.

18.3 HWU Le Blanc, France
21.4 NPM Lualualei, Hawaii
23.4 DHO38 Rhauderfehn, Germany
24.8 NLK Seattle, Washington
25.2 NML LaMoure, North Dakota
40.0 UNID (seriously doubt JJY Tamura, Japan ;p )
40.7 NAU Aguada, Puerto Rico
45.9 NSY Niscemi, Italy
52.0 UK Navy?
60.0 WWVB Fort Collins, CO
62.6 FUG La Regine, France
65.8 FUE Kerlouan, France
77.5 DCF77 Mainhausen, Germany
162.0 TDF / ALS162 Allouis, France
198.0 BBC4 carrier / UK-AMDS
Tampa, FL USA | US Map Grid EL88
Airspy HF+ Discovery | KiwiSDR 2 | 2x Msi2500 Msi001 | 2x RTL-SDR V3 + NE602 | 2x RTL-SDR V4
148' + 60' Loops-on-Ground | 31' Vertical | 18' End-Fed Vertical | PA0NHC MiniWhip

Offline ~SIGINT~

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Re: Best MWDX antenna?
« Reply #277 on: February 01, 2024, 1545 UTC »
Good RX on that vertical. I don't see most of these from my location. It may be time for me to put up a vertical and see what happens.

You will find the manual for your Lambda LCS at the following link:
https://bama.edebris.com/manuals/lambda/lcs-a

Offline RobRich

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Re: Best MWDX antenna?
« Reply #278 on: February 02, 2024, 2004 UTC »
Some longwave NDB loggings as well:

https://www.hfunderground.com/board/index.php/topic,124922.0.html

An outdoor remote-tuned ferrite loopstick probably would fare even better at longwave and below, but a simple vertical with even limited RF grounding tends to suffice at low frequencies assuming it is not completely swamped with local RFI/EMI.

I remember my 31' having quite impressive (to me anyway) low-frequency performance with a YCCC preamp. Instead of outright gain, the YCCC feedpoint preamp is designed to improve matching an electrically short antenna to a low-impedance coaxial feedline. Worked nicely for that, but it overloaded on some HF bands. It was not intended for a 31' vertical with a radial field back when I have that antenna ground mounted.

Occasionally I think about redeploying the YCCC preamp, but with a 9' or an 18' vertical element over a single ground rod as intended by the designer.
« Last Edit: February 02, 2024, 2015 UTC by RobRich »
Tampa, FL USA | US Map Grid EL88
Airspy HF+ Discovery | KiwiSDR 2 | 2x Msi2500 Msi001 | 2x RTL-SDR V3 + NE602 | 2x RTL-SDR V4
148' + 60' Loops-on-Ground | 31' Vertical | 18' End-Fed Vertical | PA0NHC MiniWhip

Offline RobRich

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Re: Best MWDX antenna?
« Reply #279 on: February 24, 2024, 1648 UTC »
The 5v linear power supply needs work. Transformer seems okay. Recapping is not too big an issue, though i will have to order some of them.

The power transistors could be an issue if they need replaced. I still need to test them. The four currently installed ones are around $30 a piece. Skimmed some potential equivalents. A few possibilities are under $10 a piece, so I probably will just swap them all if there are failed ones.

Now to check through my 5v USB switchers for maybe a temporary workaround.
Tampa, FL USA | US Map Grid EL88
Airspy HF+ Discovery | KiwiSDR 2 | 2x Msi2500 Msi001 | 2x RTL-SDR V3 + NE602 | 2x RTL-SDR V4
148' + 60' Loops-on-Ground | 31' Vertical | 18' End-Fed Vertical | PA0NHC MiniWhip

Offline ~SIGINT~

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Re: Best MWDX antenna?
« Reply #280 on: February 25, 2024, 0027 UTC »
Wasn't that power supply listed as tested / working?

Offline RobRich

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Re: Best MWDX antenna?
« Reply #281 on: February 25, 2024, 2042 UTC »
Not really sure. Lots of these types of devices are pretty much described "pulled from working environments." That tends to be more like "roll the dice" IMO.

Even if I have toss a few repairs at it, I suppose whatever, as a large 5vDC 16a linear power supply is kind of a pricey item be it new or used. IIRC, this model was nearly $600 back in the day. Barring a complete replacement of all primary power transistors, I probably can come out with like $100 or so invested.

In the meantime I likely will go pickup an Apple USB-C power supply for under $20. If needed a multi-stage EMI filter is around $10 to $15 on eBay. Doubt I would bother trying to build a filter board for that price.

I need to catch up on my browser builds this weekend. then hopefully I can get back to playing radio later this week.

On a positive and more affordable radio project note, I was next to a Dollar Tree store awhile back. A box of medium-size hula hoops was on the sidewalk. $1.25 a piece. I purchased a few for antenna projects.
« Last Edit: February 25, 2024, 2047 UTC by RobRich »
Tampa, FL USA | US Map Grid EL88
Airspy HF+ Discovery | KiwiSDR 2 | 2x Msi2500 Msi001 | 2x RTL-SDR V3 + NE602 | 2x RTL-SDR V4
148' + 60' Loops-on-Ground | 31' Vertical | 18' End-Fed Vertical | PA0NHC MiniWhip

Offline RobRich

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Re: Best MWDX antenna?
« Reply #282 on: March 03, 2024, 0612 UTC »
My KiwiSDR 2 is working. :) It is not public at the moment.

Local store was out of Apple wall warts. Found a Samsung USB 3A power supply at home. It has a little noise at a couple of spots in the HF spectrum, even with some ferrite choking, but it suffices for initial setup and testing.

Seeing as I did not get around to rerouting feedlines, I setup an old WiFi router running DD-WRT for a wireless client bridge to my LAN. I did use a linear power supply there. ;p

Hooked up my 31' vertical. Been listening to 80m amateur radio in the background. Some moderate to strong static crashing from area storms, too. Anyway.

I still need to tweak the s-meter and waterfall calibrations. I will likely dig out my RF shelf filter from some added roll off under 10MHz to potentially better equalize the 0-30MHz wide waterfall.



Tearing further into the Lambda 5v 16a linear PSU is low to no priority at the moment.

In the meantime I have ordered a couple of affordable used 5v 3A hybrid regulated power supplies for experimentation.

https://www.digikey.com/en/articles/hybrid-power-supplies-deliver-noise-free-voltages-for-sensitive-circuitry

Semiconductor Circuits ES5S3000  (EC11-300) PSUs in particular.

https://www.datasheets360.com/pdf/5490670810123532253

Plan to use a Schaffner FN9222-3-06 on the AC side, then a Schaffner FN2090-3-06 on the AC, DC, or both sides as needed.

https://www.schaffner.com/product/FN9222/Schaffner_datasheet_FN9222.pdf
https://www.schaffner.com/product/FN2090/Schaffner_datasheet_FN2090.pdf

Probably will salvage an old ATX power supply for an enclosure.
Tampa, FL USA | US Map Grid EL88
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Re: Best MWDX antenna?
« Reply #283 on: March 04, 2024, 2200 UTC »
This is my Schaffner EMI/RFI filter arrangement.



I also incorporated a fuse on the line side in the later design thinking that if something was to go wrong with the filter then it could present a dead short all the way to the fuse/breaker panel. I also recently seen a video where someone put 77 and 43 ferrites (5 ~ 8 turns ea) on the input and output leads and that had a significant improvement on reducing noise. You are obviously look at larger core ferrites and a much larger enclosure. None the less, if you get a 15 amp or more Schaffner then it might be worth the effort and filter out an entire 15 amp branch circuit.
« Last Edit: March 05, 2024, 0116 UTC by ~SIGINT~ »

Offline RobRich

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Re: Best MWDX antenna?
« Reply #284 on: March 05, 2024, 1548 UTC »
I used to basically assume 120v 15A drops as well, but IIRC, the 120v drops in this house are 20A. Built around 2004.

Anyway, yeah, filtering a whole branch is tempting. I have even considered an isolation transformer on a specific branch for certain equipment.

My most immediate annoyance is a moderate increase in the local noise floor, and sadly, there is not much I can do about it. My community continues to grow with many new home constructions in my immediate neighborhood. Suppose I should be thankful most of the homes are concrete block with stucco over wire, with the house electrical ground typically being the rebar in the concrete foundations, so there is some EMI/RFI dampening already present in the construction designs.

I was able to find a deep null in the noise floor playing around with a passive loop outside awhile back. I am thinking about feeding the KiwiSDR 2 with such a passive small loop for now. Kind of directional and admittedly "gain" well into a few dozen negative dBs, so it is going to "miss" some weak signals, but I would rather it have the low noise floor especially if eventually putting a couple of the channels online.



Update. Forget the active miniwhip. Here is the KiwiSDR 2 and 31' vertical. Skimming upper HF at the moment.


(click to enlarge)


Stats are showing 23dB SNR overall at the moment, which is about average for the KiwiSDR network. Area storms, local daytime RFI, and the USB wall wart are not helping.

I am running a RF shelf filter with -20dB rolloff under 10MHz. I still need to tweak the waterfall and meter calibrations a little more.


(click to enlarge)


The horizontal lines are static crashes from area storms. No noise blanking enabled right now. Anyway.

There is a slight dip in the tropical bands, but at least 0-30MHz does not look quite like a roller coaster. ;)



I so "enjoy" when that wideband signal pops up. I set the waterfall to somewhat better highlight it.

It is from approximately 6825 to 6975 in the screenshot. It is now about 75KHz higher.


(click to enlarge)




My KiwiSDR 2 is reporting 34dB SNR tonight. That is more like it. That said, it is still on the 31' vertical, plus the dishwasher is running right now. o.0 Anyway.



APC LineR ---> cord --> Schaffner FN9222-3-06 --> Schaffner FN2090-3-06 --> Semiconductor Circuits ES5S300 5vDC 3A bybrid PSU --> ferrite choke --> cord --> ferrite choke --> KiwiSDR 2

The power supply, Schaffner filter, fuses, etc. are in an old ATX PSU case. Even wired up the couple of cooling fans at 5vDC FWIW, and they are quiet for both sound and RFI.

I tried both a Schaffner FN2090-3-06 and a homebrew filter on the DC side. Either delivered 5vDC to the Kiwi, but it would not boot. Hmmm. That is why the ferrites are there for now.

The Kiwi has been reporting an overall SNR around the low to middle 30s range. It is still on my 31' vertical. Any further SNR improvements are likely going to be on the antenna side.

VLF and LF look decent IMO. No noise blanking needed (at the moment?).





Approximately 9' mobius loop active antenna. it is on a tripod in the den right now. It is not even near a window, and I did not bother much with even trying to null noise.

The loop is RG-11. The upper mobius crossover was salvaged from a Youloop, repaired, and potted.

The amp is packaged in a larger enclosure with SO-239 connections. The amplifier is from a MLA-30. ;p It can be changed out later for something better if desired.
on the active loop
I have a 10dB attenuator before the Airspy HF+D at the moment as the amp has plenty of gain at lower frequencies. I will work on tweaking that later.


(click to enlarge)



(click to enlarge)[



(click to enlarge)



(click to enlarge)[/urlg



The active loop is outside now. Around 8' off the ground. RG-11 feedline.

I simply turned it to get a general null one of the usual more noisy parts of the HF spectrum here.

Nulls are vaguely somewhere around WNW/ESE to NW/SE. I did not check a compass.

Gain is not uniform, but I expected that. Longwave is likely a huge YMMV. Both are aspects of the MLA-30 amp board.

A mix 73 isolation transformer between the bias tee and SDR helped clean up noise on lower MW and much of longwave, though actual LW signal reception remains a question mark.



The ~$30 HFDY loop kit at Aliexpress and similar could be of potential interest. It is based upon a simplified LZ1AQ-based amp design. Appears to use a 2SC3357, or perhaps a clone. No regulator. No lowpass filter. YMMV.

More details including measurements:

https://groups.io/g/loopantennas/topic/hfdy_chinese_loop_and_loop/103801226

Clone or real, the results look (much) better than the inexpensive video amp typically used in the MLA-30 and related designs.



FWIW, I have WWV on 2500, 5000, 10000, 15000, 20000, and 25000 at ~0140z on the active loop.

No 60Hz on the active loop. As suspected not much happening on longwave and lower with the MLA-30 amp board. Anyway.



Seems I picked the wrong noise source(s) when tweaking the loop direction. The nulls are now more ENE/WSW.

The current daytime noise floor difference on the 40m band is about 2-3dB with SDRSharp noise blanking enabled.

The NNW peak should favor more of North America. Works for me regarding that particular antenna.

The other noise source is towards 8MHz, along with intermittent and variable in strength. Noise blanking largely knocks it out, so I will try to just disregard it for now.

I might have an idea of what one of the noise sources is. I need to verify, so perhaps more to follow.



Suppose my days of HF radio are about done unless I can find the current area noise source(s), It is does not appear to be local to my house.

S5+ noise on 40m even on my LoG, which is in tens of dBs loss by design.

Replaced the preamp with a mix 73 1:1 isolation transformer for the 9' mobius loop. Not much different than the LoG.

Overall SNR on my 31' vertical is down to 19dB with noise.

Even have some EMI/RFI at ~28MHz on my 18' end-fed vertical.

I can still listen to lots of signals, but weak signal reception is trashed. That pretty much takes the fun out of HF listening for me.



Moved location and dropped the now passive 9' mobius loop down to maybe a foot or so off the ground. I am trying to use ground losses to cancel out some of the noise. It helped on several bands.



The noise source dropped out. I am hoping it is not an area solar power install.

My Kiwi with 31' vertical is reporting 34dB SNR.

As for the loop, the 9' NCPL is now about 18" off the ground. Current 7MHz noise floor is floating around S2 with my Airspy HF+D. SDRSharp noise blanking does not effect it.

I probably will have to realign the loop if/when the noise comes back. There was not much else to null tonight, so I just put the peaks back to roughly NNE/SSE.

At approximately 0145z to 0200z tonight with some static crashing from storms in the gulf.

1110KHz | -134dB noise floor | WBT 38dB SNR
5MHz | -116dB noise floor | WWV 41dB SNR
10MHz | -122dB noise floor | WWV 57dB SNR
20MHz | -138dB noise floor | WWV 54dB SNR

Noted at least couple of longwave BCB carriers. Also WWVB.

60KHz | -131dB noise floor | WWVB 22dB SNR | notebook on mains
60KHz | -139dB noise floor | WWVB 20dB SNR | notebook on battery

The NCPL feedpoint is using a mix 73 1:1 isolation transformer, plus there are a few snap ferrites on the RG-11 feedline. Also a few snap ferrites on the feedline near the SDR.

It was dark outside, so I called the antenna project for the night.



Static crashing is horrid tonight, but otherwise the noise situation seems perhaps a little better.

The 9' NCPL needs more feedline decoupling at the loop feedpoint. Suspected it might as I used only a single mix 73 binoc. It probably needs two or more cascaded. Something to poke at later.

I already knew the 148' LoG needed more choking when it was deployed. I replaced the LDG 1:1 (of whatever mix) with a Noolec 9:1 v2. The ratio is little high, but anyway, it further cleaned up mediumwave and lower for now.

Also I reconfigured some inside chokes and filters. I am back to having WWVB 60KHz and area longwave beacons during daytime on my elevated 31' vertical.

It is getting to the point of wanting more directivity than just a small bidirectional loop. I am thinking about building a SULA and deploying it on a rotator.

https://swling.com/blog/tag/sula/
https://swling.net/viewtopic.php?t=55



BTW, I am done playing with 5v power supplies for awhile. I just ordered a new (open box) Acopian VA5H3200. That is an A5H3200 with overvoltage protection.

https://www.acopian.com/store/productdetail.aspx?q=i284
https://www.acopian.com/inc/streamFile.asp?loc=info&id=AcopianCatGoldBoxLinear.pdf/

Current at 40C: 32 amps
Load Regulation: 0.005+/- % or 2mv
Line Regulation" 0.005+/- % or 2mv
Ripple: 0.25mV RMS

BTW, I suppose the hybrids were not bad for the price, but they were still not quite what I wanted.



Today I noted a new solar panel installation on the next street. The direction appears to correlate with one of the annoying daytime noise sources, and the 20KHz spacing lends further support to a potentially noisy inverter.



The 9' passive loop is back to elevated. Maybe 7' or so. Added more feedline choking.

I have other mixes of toroids on order to potentially further modify the feedpoint transformer.

I might also experiment with changing it to a shielded loop. All I have to do is swap the mobious crossover at the top for a short coax jumper with a shield break.



Ordered an HFDY loop. I pretty much simply want the amp board, but anyway. ~$30 for an assembled LZ1AQ-based loop is decent IMO.

As noted earlier, the HFDY loop amp lacks a low-pass input filter, has no onboard voltage regulator, and has lower OIP2/OIP3 performance than more expensive LZ1AQ designs.

1. A 30MHz low-pass filter between the loop and amp is not difficult to implement, but I doubt it will be needed at my QTH. I have tested rather large antennas and cheap high-gain preamps without noticed FM overload here.

2. A voltage regular on the amp board is not really required if using a decent power supply. I can do that so whatever IMO.

3. The OIP2/OIP3 is still okay enough for my intended mostly HF purposes. At any rate the OIP3 as measured appears to be around 9dB better than the first-gen NE592-based MLA-30 amp board.

On a tangent related to the MLA-30, I ordered a couple of inexpensive NE592 preamp boards as a starting point for some further experimentation. Basically this in the through-hole version but without the bias tee components:

https://www.pcbway.com/project/shareproject/Antenna_Magnetic_loop_on_video_amplifier_NE592_DIP_version_10ff2fb5.html

They might prove useful enough for later projects after a little work on the input and output sides.

^Multiple posts merged.
« Last Edit: March 31, 2024, 1216 UTC by RobRich »
Tampa, FL USA | US Map Grid EL88
Airspy HF+ Discovery | KiwiSDR 2 | 2x Msi2500 Msi001 | 2x RTL-SDR V3 + NE602 | 2x RTL-SDR V4
148' + 60' Loops-on-Ground | 31' Vertical | 18' End-Fed Vertical | PA0NHC MiniWhip

 

HFUnderground T-Shirt
HFUnderground Garden Flag
by MitchellTimeDesigns