Reference Station: Samlex SEC-1235M 13.8 VDC Power Supply

[@onemorething100]

I almost bought the MFJ when I bought my ICOM 7300. DX Engineering guy told me to stay away from them. After watching your video, I'm glad I did. I went with his suggestion. The Samlex.

[@shawjw247]

Hello, I am a "maybe" proud owner of the MFJ-4225MV. The fan is loud and distracting! I installed a temp. sensor, (40c/104f , N.O. Switch) on the fan wiring. Also, I drilled out the holes on the sheet metal external housing, closest to the fan. (3/16" drill out, and 3/8" countersink exterior openings/holes) This reduced blower noise somewhat and the temp. sensor was a good addition. In closing, the skill level includes deburring, sanding, BO Drill, Dremel pencil grinder/finisher, a well equipped tool shop, and possible spray painting exterior cabinet shell. (Dave, thx a bunch for all you do in the ham radio world.) de N8NSK

[@markmarquardt8016]

Dave, thanks a million for thaking the time to do this series. I need this help and guidance as I set up my station. I live out in the sticks. Nearest neighbor is two miles away. This will really help to keep my family safe and secure. Best wishes always.

[@jedi_mario]

I love the series. I am prepping to build my station now. I cannot wait for the next videos. Thank you for elmering me!!!

[@chuckcee9068]

I was researching power supplies when I came across your channel. Excellent work and it’s very much appreciated!

[@pfmcdermott1]

I like your description of the fan at 10:34. I definitely got an idea of what your experience was from the delivery. :) (also +1 spontaneous “that rings a bell” comment at 11:15). Thank you for the heads-up on the fan, and more seriously, the entire video review. This is incredibly helpful as a new ham trying to set up a basic station. I’m starting with a vhf/uhf because this whole process is going to be done over time due to the money needed and I appreciate getting one power supply now instead of finding out later I should have gotten a different one to run the eventual HF rig. Thank you!

[@lgrizzly]

I’m sure you are full of numbers and nomenclature but to add to the pile..... the “computer” AC connector you mentioned several times is an IEC 320 C14. The C14 is the side on the computer and C13 is the side on the plug. Thanks for all your videos. They are immensely helpful.

[@DanLeonardpb]

been hemming and hawing around, ending up pulling the trigger on the Samlex. Thanks David, your videos are incredibly helpful.

[@cliffengle2897]

Good video as always, Dave. When buying my first rig, HRO strongly recommended the Samlex 1235M. I now have 2 and no problems ever. Keep up the great work! 73

[@goodxrvn2053]

Thank you for the very informative videos. Just a note, the User Guide for the Samlex 1235M specifically warns the User not to use bare wire inserted into the 12V power output but rather the supplied posts (not mentioned). The reason for this is as you discussed, the screw fasteners will splay the wire. Thus potentially causing a less than optimal connection and possible overheating of the wire insulation/fire. Yes, you did tin the wire which does help but this point should have been made to avoid confusion. Thanks again for your excellent instructional videos.

[@RobertMacCready]

Just got my Samlex 1235M today and was reading the brief instructions. It says "do not connect bare stranded wire end directly to the DC output terminals as the strands will spread" P12 in my booklet. They give you 2 terminal lugs to use so you can avoid any sparking/melting/overheating, with a possible poor connection. Cut the tips off to fit the lugs they gave you and solder the connections to the terminal lugs. Don't go the whole length of the lug but just the larger round end. They tell you to crimp the ends but I would solder them.

[@thomastammaro693]

Thank you! Myself and the gentleman whom is mentoring/ Elmering me were perplexed on how to connect the Ic73 to the power source. Nice job!

[@Kori114]

Got my IC 7300 pretty cheap and now I am getting one of these since they are one of the only available power supplies right now for immediate delivery.

[@whome8192]

I have purchased switching power supplies marketed for hams that generate an annoying amount of RF noise(make rx impossible). I have also purchased supplies that become unstable when switching on and off that the output voltage goes super high, or reverse polarity!. The Samlex 1235 has been the best one I have found. I have had to replace the filter capacitors...but best unit I have owned.

[@PaulReedy]

Just ordered one of these supplies you recommended. Before that, I had bought one that's the guts of one of these but no meters, or a nice case to put it in. My old icom PS15 measured 14.2 volts, so that's what I set my switching supply to. The switching supply is nice because it pulls less power, and creates almost no heat compared to the PS15 which contributes to warming my office.

[@aldimore]

I bought a Samlex SEC-1235M and used it with my IC-7300. Then I got an IC-9700. When powering just the IC-9700 in receive, the Samlex runs the fan a good 10 minutes every half hour or so. Its sitting alone on a shelf with air on all 4 sides. Wanting a new one that can power both and not be so loud.

[@Littlelewie151]

I have a few power supplies around. I do some repairs on various electronics and I love the variable voltage supplies for starting at 0 volts and climbing. I once caught a short in a cb at roughly 2 volts. Long before it would have damaged the radio.

[@ifpo238]

Same boat as Mario Leal; working on building my first HF station, and loving this series. I bought an MFJ-4230MV a few months back, so I'll be diverging from reference on that point... Also planning on using an autotuner (ATU) and doublet antenna.

[@W5AKC]

So, for the SEC-1235M how is this grounded and bonded since there is no chassis ground? I have this power supply and an Icom 2730A radio. Being told I need to ground and bond them in my station, but nobody provides the how!! Any info? Thanks!

[@michaelfarrow4648]

I have had a SEC-1235M for a while now and I really like it. I recently had occasion to contact Samlex support. It was a totally positive experience - the people I talked with were very helpful and responded to my 1st email within 1 hour!! I highly recommend Samlex.

[@georgemoomaw9437]

I am going to take a wild guess here. Unlike me, who is just getting into ham radios, you have been at it for a couple of weeks now. Great video. I have learned a lot from you. Thanks Dave.

[@RhettSparrow]

Is this a joke or you are being serious, i can’t tell at all!

[@no5x937]

Use crimped ferrules on bare and soldered wires for improved conductivity and reliability.

[@webmastercaribou7570]

I am a fan of linear power supplies over switching.

[@davecasler]

You're not alone! The linear power supply market is large and they're readily available.

[@daniel4v3]

Thanks!

[@R2AUK]

SEC-1235M is a great choice. I've been using it for over a year. It works great and it's very quiet. If you are using only SSB, the fan will be not turning on at all. It goes on only after about half an hour of calling CQ in 40W digital or 100W CW, and even then is not that loud. 73 de R2AUK

[@coryt8482]

Samlex is a good company, I lost the power cord for mine in a move, contacted the company to buy one and they sent me one for free.

[@f15sim]

FYI, you're better off using a crimp ferrule when inserting wire into a compression terminal vs a tinned lead. Thermal cycling of a tinned lead in a compression terminal will eventually result in a high-resistance connection and cooked terminals.

[@BillSchell1]

I've had my Samlex SEC-1235M for two years now. Very nice supply, but quite noisy when it decides that it's too hot, which happens after about 30-60 minutes of continuous FT8 QSOs. It'll switch on its fan for around 5 minutes to bring the temperature down, making the shack a somewhat unpleasant place for that time. However, there is a mod, which I've done to mine, which runs the fan full time at a very low speed (almost but not quite inaudible). This is enough so that the power supply doesn't get hot enough to trigger the high speed noisy fan mode. The mod is very simple, it just wires up the fan through a resistor to power. If you google 'radiodan samlex pdf', you'll find it. Thanks for the excellent videos. -- Bill, W2WZ

[@paulhg1ztn]

I have a samlex unmetered version and it is as quite as a church mouse rf wise handles my TS590 at full power on Ft- 8 with no problems.

[@kevingary7018]

My latest order from DX Engineering came with a catalog and stickers!

[@josephvandyke2150]

Got that power supply and I liked it so much I bought one for my father

[@sincerelyyours7538]

I've had an MFJ-4225MV P/S for nearly 20 years. I don't think it is a re-branded Chinese or Taiwanese product but components could have been built for MFJ in those countries. Works great as a 12 V test bench power supply with no CC capability. The limited range voltage adjustment also makes it a great current source for Lipo battery chargers or cutting foam wings and bending 1/8" acrylic sheets. Haven't used mine to power a ham rig yet but I'm sure it will work fine for that too. No kids to worry about so curious fingers are not a problem for me. The fan noise doesn't bother me either, but if it did I'd probably install an NTC thermistor or some other circuit to adjust its speed automatically.

[@davecasler]

I said that because I remember seeing that same power supply for sale from Chinese sources.

[@WA8QFE]

Dave, I had destroyed a couple projects with the MFJ supply until I realized that on power up there was a 28vdc spike that smoked anything that had the collector hooked to the +Vcc , including a 100 watt 2m amp. They needed to add a choke to the output. The version that has the cigarette plug rated at 7 amps, has a choke in line with that output. Lee, WA8QFE

[@davecasler]

Good point. Always turn on the power supply prior to turning on the radios.

[@MrLoretano77]

Dave I love it you bought the same radio in the same power supply that I bought when I got my ticket back in September. Love your videos 73 KC3NYT

[@timothyone1]

You're looking great! So glad to see you doing so well!

[@chewmanfoo]

When reviewing the power requirements for the ref transciever, it showed maximum current requirement at 21 Amps. Does this mean that the wall receptacle the power supply is plugged into needs to be wired to a circuit breaker that is larger than 20 Amps? Sorry if this is an elementary question. I did take circuits class in college, I passed, but I can't remember this answer.

[@davecasler]

The AC input is 120 volts AC at about 3 or 4 amps. The output is 13.8 volts DC at up to 30 amps. Slightly more power in than out, but the modern power supplies are more than 90% efficient. Hope that helps. I did a video on this question awhile back.

[@stridermt2k]

Awesome stuff! Always enjoy the content! Just finished the Extra manual and am now engaging in rigorous practice testing! 73 de N2NLQ

[@davecasler]

Good luck with your test!

[@graywolf1911]

Another great job Dave. I have an Astron PS, but I like the one you chose also, nowhre near as heavy as the Astron with it's beefy xformer.

[@donmaynor3816]

Great stuff as always Dave!

[@TheSmokinApe]

As always a very informative video! 👍

[@douglaswilliams6834]

Astron RS-70M for the win. :-) Call me old fashioned, but I prefer linear power supplies.

[@matthewmiller6068]

Great power supply that 1235M - though if you use more than one device at once some electronic radios reboot. I added a 3.5 farad car audio transformer to it which made a world of difference when a 2nd large load kicks on (e.g. 2 radios TX at once) such as running FT8 while doing APRS or FM voice running near the max continuous output power. Holds voltage great and RF quiet though and works fine for 1 at a time. I was able to put two wires under the screw terminals no problem (one 12awg, one 10awg) and they seem very secure after tightening the screws down

[@davecasler]

Thanks for the tip.

[@mikebavoso26]

Thanks for all your videos I am total off grid and would like to know about your HF amplifier that operates on 12 vdc? Thanks

[@kevinkeppler7220]

KW1W - Just bought one, like the silent fan. Can I connect it to my RF ground bus? Except for the fan, all of the screws are anodized. How did you connect it?

[@koldark]

I got the MFJ-4230DMP with the built-in powerpole connections (2 of them). I figure that will last me at least for a bit.

[@timwall5312]

Dave, thanks for all you hard works an perseverance with your videos. You truly shine as an example of an mentor or Elmer to the KZbin generation. I have a quick question on grounding the Samlex SEC-1235M power supply. I did not see a grounding lug on the supply. I am assuming a ground to one of the chassis screws would suffice, or is there no need to add this PS to a grounding system. Your sage advice on this topic is greatly appreciated.

[@JimmyShot]

Did I miss it or is the power supply distribution video already been done? Cant find these videos in a playlist so its hard to keep up

[@marshallvanwagneriii1495]

What is the common failure mode for the switching power supplies? Are they protected against a dead short at the output? I'm very interested in the light weight of these supplies, but I don't know very much about them. Thanks for another great video!

[@davecasler]

Yes, these power supplies have built-in protection for shorts.

[@kodikodi9948]

this is great information. THANK YOU

[@xjohn1970]

Hello. I Have a 20 Amp 13.8VDC Linear Regulated Power Supply highly stable, high quality. My question is on the unit it says 20 AMPS Constant / 22 Amps Surge. What is the 22 AMP Surge for? I love this Channel. thank you for all the info. 73s

[@DonDegidio]

Hi Dave, This will be a great video series for those starting out looking for proven equipment. 73 WB3BJU

[@mikepeterson443]

No stickers? Sticker shock?

[@prestonshute7243]

Just ordered my SEC-1235 for my shack. It’s on back order but they should have some in on 5/4/2020. Thanks for your super video and all your hard work. 73 wd4dda

[@bud03038]

Not happy with the PowerWerx SS-DV30, found it very noisy on 80 meters , but love the ic-7300! de WQ1I

[@gac5329]

I can hardly wait for the next videos. How many videos will be in this series?

[@davecasler]

As many as needed. I plan to make most future videos based on the reference station.

[@1crazynordlander]

Thanks for sharing. I have the IC-7300 with the Astron 35 amp with meters and power poles. I am looking forward to your power distribution solution. Are you making it? Passed the Extra Exam last Saturday. In our area I have to drive 100 plus miles to find a exam session. We had had a wind event that plugged our roads with snow. I left at 5:30 in the morning to be able to get to the test on time that was 120 miles away. I had a difficult time finding a road in our local area that wasn't blocked by snow drifts. It was quite an ordeal but it is over now. I went from Tech to Extra in 11 months time but I know that there are those who go Tech to Extra in one session. I credit you for my success. Expect another tip soon.

[@alexalonso2093]

wow.....talk about a challenge...well done..wish someone would figure out a reasonable way to take the test location wise..maybe taking it ONLINE....that would help bring new ppl in.7 3

[@davecasler]

Congratulations on your test results. Now that you're an Extra, perhaps you can find two other willing extras and set up testing in your local area!

[@michaelmullins3396]

Dave , Have you done anything on high current server Power supplies and their conversion for Amateur Radio Use.

[@vne2328]

Is 600mV too much ripple on the SEC-1235M? Do you know the switching frequency? Edit: Looks like the SS-DV30 was lower at 200mVpp.

[@LEXPIX]

Hello, and thanks for taking the time to make these informative videos. I'm just starting out in Ham Radio and about to upgrade to my General ticket. I've just purchased the IC-7300 and the Samlex SEC-1235M Power Supply shown in your reference radio series. Couple questions: 1. I want to run my rig portable and was wondering if I need to use a power supply out in the field, or can I run it directly from a LifePo battery assuming voltage and amp requirements are met to power it. 2. Is it possible to convert the power connector on the back of the IC-7300 to Andersen Power Poles, or do I need to get the icom connecter and make a power pole connection on the other end of the cable? My Bioenno LifePo battery came with an Andersen Power Pole connector. - Again thanks for the great videos and encouraging new Hams liek myself to further explor the hobby.

[@jeffrobison2013]

I run all my radios on a 50a astron. only been turned off prob 3 times in 27 years

[@davecasler]

I've been running my radios on solar-charged batteries. Been doing so for over two decades.

[@williamstaylor5449]

@@davecasler What type of batteries are you currently utilizing in your station?

[@jeromemckenna7102]

Question from a beginner. If your radio calls for a max current of 21 amps, and your power supply is 13.8V with a max of 30A is that a problem?

[@davecasler]

Not a problem. The key factor is the voltage. The radio will draw whatever current it wants and that varies quite a bit during SSB transmission. The current capacity of the power supply is the maximum it can supply.

[@jeromemckenna7102]

@@davecasler Thanks very much!

[@bsdguy]

Hi Dave, thx for another great video. My question is what's the pros/cons of using a variable power supply over a fixed voltage power supply? I currently have a Astron VS-35M that I used with my Midland 2m and 6m land mobile radios. I'm using your videos to prep for my general license so I can use my Kenwood TS-530S.

[@judd_s5643]

Dave, would be helpful if you would include a picture of the labels that are attached to your recommended reference station equipment. My particular purpose is to determine what regulatory agency approvals (UL, CSA, TUV) are claimed by the mfg. As a former Homologation Engineer I’d like to point out if a “person” buys equipment from a foreign country and imports it into the United States that person is legally the importer of record and is totally responsible for the equipment. Hypothetically if you purchase a device that plugs into our mains (wall outlets) and the device catch’s fire and burns your house down your insurance company will spend time/dollars to develop a case against paying your claim. Yes I know, those insurance agents are your best friend when accept your money but make no mistake about it when a claim is presented it goes to a entirely different group of people whose whole purpose in life is to legally deny your claim. My recommendation are; 1. Only buy from a company that is the legal the importer of record and has financial resources. 2. Require a NRTL Mark ( UL, CSA, NOM, TUV ETC.) be affixed to the equipment. 3. Don’t rely only on the CE mark, specifically if your outside of the EUROPEAN UNION. The CE mark is not a independently verified claim like a UL, ETL MARK, it’s a Declaration of Conformity by the mfg. Within the EU the person who signs and makes that claim is personally responsible and can and will go to jail if the product is not in compliance with the appropriate directive.

[@davecasler]

I put a photo of the manufacturer's label on my website at dcasler.com/2020/02/20/samlex-sec-1235-power-supply-manufacturers-markings-and-certifications/.

[@James_Bowie]

The correct name for those mains sockets is IEC.

[@francismcclaughry3794]

I just got a new 7300 hundred. I don't have any of the power supplys you talked about. I do have to astrons and they put out twenty volts. I run my five ninety on a twenty watt one even though it called for a twenty five watt one. I now have a marine power supply that runs at forty five watts continuous. I hoping the radio will only draw the power that it needs. I wish I had some one that I could converse with to seek aprovial off a second opinion, but I think I will be safe hooking up the radio. I like the old days when there was a nice group on forty meeters. Always takes someone to spoil radio. I have taken more to being on this thing. because there is no jack leg that can ruin it. I sometime wonder why i bought the new radio when it is dead out there. I did listen to a conversation on twenty meeters last night.

[@denelson83]

I would not be able to use 21 amps in my home, as my wall outlets can only safely supply 12 amps.

[@kevinh9333]

Taiwan produces some good stuff, great video!

[@johnratcliffe6438]

Does the 'OG' stand for 'Original Gangster'?

[@dougdukes1039]

Any chance to get the whole list for the reference station. Might want to build along... Or at least start saving my lunch money.

[@davecasler]

I'm researching as I go. I have an idea where I'm going but I've got lots of research to do.

[@dougdukes1039]

@@davecasler Thanks patience is a virtue..... just not one of mine.

[@Ed-hz2um]

Another great video, Dave. I'm following this series in particular since I have a 7300 on its way (Yay!). I've read a few articles about switching supplies producing noise, so I've always used a linear (Astron RS-35A right now). Any opinion on this? 73, KE6BN

[@bradcfi2]

I use the Astron as well. However, I think the right switching unit is just fine. I plan to get a Sammlux (sp?) Good enough for dave, good enough for me. Let's save some idle current.

[@giffjim55]

Great video series

[@antandshell]

Would love to see the Samlex on your oscilloscope.

[@davecasler]

Noted! It would be easy to check out.

[@sq2jul]

​@@davecasler thanks for this video and many others you already did. They are really helpful and explains a lot of radio things. I would be glad to see a simple comparison - if it is possible, please show us spectrum scope of ic-7300 (or any other SDR) battery powered vs ic-7300 powered in use of switching power supply presented in this video. It is tempting to buy those tiny PSUs but I have not so good experience with HP server (switching) PSU (HP HSTNS-PL18). The HP PSU wasn't total disaster but far from being clean and silent as many other ham radio operators tries to advertise them. I mean in terms of RF noise. I am wondering whether those from Samlex are any better? 73 de Juliusz SQ2JUL

[@davecasler]

@@sq2jul The power supplies made especially for ham radio are particularly RF-quiet. The Samlex is a particularly nice supply.

[@James_Bowie]

Rather than soldering such cables, I prefer to use ferrules.

[@brentjohnson6654]

Hey Dave, I am back reviewing the reference station and I am here for the power supply. Would you recommend having a 12VDC battery bank on a solar system? Why or why not? Also if I were to use a battery bank, my concern is regulation such as stable output. Hope you are doing well. My life has been interrupted with the changes because of the pandemic. I have a tower that is ready to raise a inverted V via pulley on a bracket. Also clearing out the room from the old junk ... errr ... equipment has me working slowly as far as progress is concerned. I hope you are doing well. Thanks for your part of keeping the Ham community educated. Cheers! 73

[@davecasler]

Yes, you can do solar. I have a solar system set up myself. I have a little box that boosts the battery’s 12v to a more radio-friendly 13.8 volts. See www.westmountainradio.com/dc_power.php and look at the N8XJK device.

[@timbacchus]

You look like you feel better.

[@davecasler]

I do. I've lost some weight and am getting some exercise.

[@s_linz]

The newer mfj costs less, had less fan problems, and puts out more current! (4230)

[@s_linz]

But, on the down side, there are only banana plug/compression binding posts. They didn't even use 5-way. So I had to solder the 7300 cable to a banana. This justifies your choice!

[@francismcclaughry3794]

radio was made for every one a little thing for every one, some like contesting. I personally like to rag chew, but it has gone south like the Cb radio did. yes I was a eleven meeter kid. in the days I used to run a cobra two thousand a three element beam which was electronically controlled. and a palmor three hundred when c b was in it hay day. the Cobra is long gone, but I still have a rad shack setting on the shelf. it was my first single side ban radio. I know there is hams out here that would not want to admitt that they were eleven meeter band children. I just love radio and I hate to it go the by way.

[@glenmartin2437]

Thank you. N0QFT

[@petrolhead9027]

No fuse?

[@davecasler]

The power supply has internal protection for over-current situations.

[@jeepien]

There are fuses in both legs of the IC-7300 power cord as well.

[@zl2seazl2sea98]

Dave, check the start up voltage spike on the Samlex power supply and you will see its over 20 volts!! regards Nigel ZL2SEA

[@davecasler]

I did check it and did not see any. But...one should still turn on the power supply prior to turning on the radio.

[@williamstaylor5449]

@@davecasler That is the way that I do it... Turn on the PS, wait 15 seconds or more, and then turn on the rig. And, turn off the rig before turning off the PS.

[@zl2seazl2sea98]

@@davecasler Hi Dave, I have two of these Samlex power supplies they will work on 230 volts by changing a jumper lead inside if you refer manual. I am using then on 230 volts in NZ, great power supplies but they do have a high start up voltage, but once going are great. yes agree to have radio turned off prior to starting power supply. I also have 2 off the Powerx SPS-30DM and the MFJ one, great videos many thanks Regards Nigel ZL2SEA

[@tomwold8269]

Wow that seems like a really small power supply for 30 amps

[@davecasler]

The SS-30DV is even smaller. The switching power supplies are nowhere near the size of their linear counterparts.

[@arnecarlsson9740]

Stay away from Samlex inverters and inverter chargers they are very noisy on the low bands.

[@davecasler]

So far I haven't found any evidence of conducted or emitted noise that affects the receiver.

[@robjanusch998]

Dave, PLEASE stop flashing the units around when you describe the units !! VERY hard to watch!! Thanks for the info !!!

[@larryjanson4011]

communist china or taiwan. were is the difference? seeing as communist china says they own that little island state, just like they own hong kong. sad not made here in the USA.

[@SiezureLips]

CLEAN YOUR ROOM!

[@davecasler]

My wife says that all the time too.

[@margaqrt]

A StepIR antenna and a 7300, yikes this new hobby is getting expensive.

[@davecasler]

The SteppIR BigIR is not part of the reference design due to cost and complexity of use.

[@montybates5176]

Great video of course but I was hoping you might mention prices. Easy enough to look them up I guess. 73 de KF0GPX