That radio is a Cushman MCM - 5. Radio repair text into measure signal strength ... I would reach out to Mr Carlson's lab on TH-cam and see if he couldn't give you some information or possibly do a restoration.
Fun video, Gabe! The radiation pattern of a discone is narrow in the vertical plane, so it doesn't receive signals from above well. You'd probably do better on those ISS SSTV signals using your NOAA weather satellite eggbeater antenna. Hope you get some use out of the 'Spy Camp' radio! I wonder what its history was?
I've been watching enough shango066 to know that you NEVER power up an old piece of electronic equipment (especially one with vacuum tubes) unless you test the capacitors to make sure they aren't shorted. Things can get very explodey if you just pound some electrons into it without knowing its condition.
FM notch filters only provide about 15dB of suppression. So if they're on the downstream (gain) side of an amplifier, they don't do that much--the signals "seen" by the receiver will be roughly similar to what you'd see without your LNA. When I was doing APT experiments about 8 years ago, I had FM-notch, amplifier, cable, radio. Also, an LNA is *useless* if it's right next to the receiver--or to be more precise it's no longer an *LN* Amplifier. The noise figure of the LNA is added to whatever losses are ahead of it, so you always deploy them snuggled right up to the antenna. Your FM notch filter will have a small amount of loss outside of its suppression band, but can still be usefully used ahead of an LNA.
2nd this as a qualified ham. If there's a few particularly strong interference sources you could look at notch filters. Vintage computer people might get mad at me for this, but if you can find a load of surplus 10base2 RG-58 network cables and BNC tee adaptors for cheap, you can use shorted stubs of coax in parallel with your receive line to very selectively "notch out" offending channels. You'll need a tee adaptor and a BNC cable "stub" of a certain length shorted at the end for each channel you want to filter out.
You want to first filter out the strong FM bevor you send the signal to the LNA so it does not get overlaoded. And you want both as close to the antenna as posible that way you have the strongest posible signal for your LNA to amplifiy
That Cushman is definitely older than the '80s based on the style and tubes, and might have been designed much earlier than the '70s even. Appears to be a bench unit for testing radios. Maybe one of those long running products.
This video is definitely one of those videos for people who like taking things apart and looking inside them Just to see how they work.Thank you for showing us all the neat little Do dads that live inside of old technology. keep continuing to make these videos so that we may enjoy them for the rest of our lives
one of the things ive noticed as a non radio guy tinkering with sdrs: ADS is one of the easiest things to receive! Even without a dedicated ADSB filter anywhere, I can get 30 or so adsb hits in any 10 second period. Nothing beats having the transmitter fly over you, even if your antenna is supposed to have a null pointing up.
I listened to a whole lot of 60 and 49 meters through a discone antenna set up inside of a ground floor apartment. Sometimes common wisdom can get in the way of a good time. Thanks for the video.
Hey, Gabe. The biggest problem with that discone is it's pattern. Those elements are designed to give a low take off angle for listening to ground stations, plus a small amount of gain making . Throw together a dipole for comparison. Sweeping it (or any antenna) with a VNA will give more answers, so don't stop with just measuring SWR Also look at the return loss to know the antennas efficiency. Hams and other hobbyists think that SWR is the holy grail, but it's just the beginning of the quest if you choose to travel far on that road. The QFH antenna is designed to interface to a rotating signal if you will. I'm not sure how well it will work with a static signal, but there will be some loss. You figured it out, the reason you see so many harmonics is bc SDR's of this type do not have any filters whatsoever, while band specific receivers (and transmitters) have band/low/high pass filters built into them. The filter is only capable of taking X amount of signal out, and you also learned this by putting the filter before the amplifier. The losses through that filter (which you could also measure with a VNA) are negligible compared to the noise not filtered out by the filter. The Spy Camp radio may have a bad stage in the front end, which would be why you can only hear maybe the strongest FM station. Look at the caps in it, and if they have any that are leaking, are wax, or don't look like modern devices then replace them with the same values. The only exception are the domino caps, those usually last forever but test them anyway.
That Crushman would undoubtedly be a very good performer... if it were restored and aligned. Unfortunately I tried to find a manual to link to you and couldn't find one. You're probably going to have to go over it looking for drifted-to-out of tolerance resistors, failed capacitors (be especially mindful of electrolytics outside the power supply section). And then you'd need someone with a good quality tube tester like a TV-7 or Hickok 539 for all of those tubes. Even in 1974 tubes were on their way out, the look & feel of the thing is more late 1950s/early 1960s (that blue-gunmetal-grey was big around then- see gear made by Hammurland, Heathkit, Hallicrafters from that era and you'll see how popular it was around then). Done properly, the higher end tube stuff should blow most modern stuff out of the water but you're not going to find a lot of high frequency coverage in that era of gear. My Hammurland HQ-180 blows the pants off of my SDR stuff for anything below 35 MHz.
😃I like your videos because they are accessible to almost everyone, you can see that there is a lot of passion and self-learning, experience nowadays is a rare thing, today enthusiasts are less and less, but there are many professors who study on google and youtube and then teach with zero experience and do tutorials. With a professional SDR like a sdrplay RSP1B or RSPduo, you would have no problem with external filtering, they are 14-bit SDRs with built-in filters, so today they are the best choice between cost and quality, they are another planet compared to the cheap ones with 8-10 bit sampling without filtering, to do what you do even the nooelek with external filters is fine, my disk is a Sirio SD 1300 N RX: 25-1300 MHz TX (ROS ≤2): 49.5-50.5, 120-180, 215-300, 415-465, 610-650, 710-1000, 1130-1300 MHz! TOP
A very beautiful tube device; with a little care, it will work like new again. I love these devices; they are very sturdily built and will most likely survive any EMP. The antenna is really good-I used to use one like it in the past.
SDR receivers are a neat toy which allow you to hear a wide range of frequencies, but they have very poor Selectivity and also cannot handle strong signals. The add-on filters are needed because the manufacturers have left out the critical RF filters that you would find on a more expensive receiver. One thing the SDR's do have is a fairly high Sensitivity, which means that they can hear fairly weak signals. The down-side of Sensitivity without adequate Selectivity, is that the stronger stations (eg Broadcast FM) will cause overload and give spurious signals right across the dial. The basic rule of RF designers is "Coils before Transistors" (eg "Selectivity before Sensitivity"). The problem is that Transistors are cheap, while Coils and Filters are expensive. Once your design allows strong signals to overload the set, you have lost the game. To improve your SDR, one of the most useful things is an adjustable attenuator. If you see FM stations everywhere, your are into gross overload and cross-modulation, so you need to greatly reduce the gain so that no longer happens.
Gabe: It looks like the MCM-5 is a piece of test equipment, not a general-purpose radio. It operates on a few specific frequencies, defined by a set of crystals in a crystal oven. The table on the inside cover shows you the frequencies available for that unit. The selector knob lets you choose between those frequencies. Use the ZERO FREQ. ADJ. function and knob to tweak the operating frequency, probably by comparing the CRYSTAL OUT signal to a reference. (I used to use WWV for checking a frequency counter.) If you're testing a transmitter, you can use the MCM-5 to check different parameters, selected by the knob at lower left. SIG. LEVEL appears to be pass/fail, shown by the green scale second from inside on the meter. To see how far off the transmitter carrier frequency is from the reference, use the "CARRIER FREQ." mode and the two outer scales of the meter. To check the peak FM deviation, use the 18 Kc or 6 Kc. FM DEV functions and the red scales on the meter. (IIRC, FM broadcast uses 100 kHz deviation. 18 and 6 kHz are "narrow band" FM, for communications equipment, rather than high-fidelity music.) The "FM MOD. PEAKS" switch allows you to check peak positive or negative deviation from the carrier frequency. The SIG. GEN. function allows the unit to produce a signal for testing receivers, with the SIGNAL OUTPUT ATTENUATOR selector switch and pot adjusting the level (albeit uncalibrated). I don't know what the HARM. AMP TUNE function and knob do, nor the (apparent) ten-turn pot for GEN. LEVEL SET.
I am currently listening to a podcast called "lost terminal", and it mentions a lot of radio related stuff (vhf, satellite, etc); i'm slowly understanding what they are thanks to your videos haha
The position of the filter at first make sense for me : if the filter reduce, let say, 3dB, on weak signal, it could be send to noise level. If put after amplifier, you already amplified harmonics and fm signal, for, let say, +15dB, so you just removing 3dB on a strong signal
My fave radio when I was a pre-teen was a Stromberg-Carlson AM/FM receiver, designed in the 1950s, and we got it from a nabe who was unloading a bunch of things. Tubes, of course. I still had it into my late 20s...... I also had a Hallicrafters multi-band shortwave receiver--similar vintage. Now, they are rather more rare, and when you can find them, they often fetch a pretty penny....
The main issue with the discone for trying to receive from the ISS is that the discone is great for low angles. It's exactly the wrong antenna for talking to satellites, which are both way above the optimal angle and also circularly polarized. That's why you had better results with a dish - you could point it more easily.
@@cottonfoo The one thing they absolutely excel at is bandwidth, which in some cases is exactly the thing you need. Especially if you want a 'works well for any band' SWL antenna that has no active components.
Verticals are not good at copying the ISS. Consider the radiation pattern. There is a huge null on the vertical axis. Think of the pattern as a doughnut. Up is the hole.
since the Cushman uses crystals to set the receive frequency, you will really only be able to receive stuff on those frequencies. You could replace one of the crystals with a DDS (direct digital synthesizer; a single chip sort of thing, controlled buy a microcontroller) and this would allow you to tune across the range of the DDS rather than be locked to a single frequency
Two things. I think you have the baby Discone antenna. I remember there being two sizes available when I considered getting one and one was quite a bit bigger than yours. I also remember the larger being the one to use on 6 & 2 meters. Second, I have the SDRPlay RSP-1 receiver and I never have trouble with 2nd or 3rd harmonics showing up elsewhere such as FM broadcast signals. I wonder if its a matter of not having filters in the receivers your using. Bonus, the antique which looks late 60's to me looks very interesting. Toss it to me if you need to save space, but yes, restoration would be a good idea for it likely has bad caps and perhaps out of spec components now.
I constantly snoop on VHF because the cops in my major metropolitan city pirate 150 to 160 MHz for chit-chat and they're a blast to listen to. I have an old 5/8 wave 2m vertical at 25 feet and a Radio Shack PRO-2006 with a computer interface. I run an awesome program called Probe to control it. The selectivity and sensitivity of the 2006 beats the pants off any SDR I've tried.
Most discones have a center element that sticks out the top... does yours not have one, or did it not get installed? If it's missing, that would explain why it's not very good at VHF...
I think he got the one without it. I got tripped up by that on amazon too when I went to order one. I think he got the 1410 without the VHF, the 1411 is $10 more and has it.
@@NickDelDuca "Without the VHF"????? 25 MHz to 1300 MHz is VHF to UHF (with the very upper portion of HF thrown in), and that's what the Tram 1410 shows for frequency spread, and looking at the 1411, there's a LOADING coil at the base of the vertical element and it's for CB which is NOT VHF. I use mine to transmit and receive on 2M, and that IS VHF.
I always like how you call things "not effective or useful" based on you not knowing how to use them, or antennas not working well based on you using long pieces of the worst coax known to mankind with 500 adapters on the end. That's a very recurring theme on this channel
I have a discone antenna as well, it's up at the 6 mtr pole, ofcourse the higher the better. But for satellites it doesn't work very well because when there is a high pass the signal fades away, you probably need a horizontal antenna of atleast something with a wider angle if that makes sense. Weather balloon reception however seem to work decently. As for local (air) traffic or FM radio or 2 mtr/70 cm it's all fine, yes you can do much better but you'll need a frequency tuned antenna with more gain but this does everything a little.
Discone is perfect for an old school scanner. If you get one that will do 27mhz and 800 trunked at once then you will have cb and police all on one antenna.
In the 70's the Air Force used a unique 'multimedia' format that combined slideshow, 16mm film and simulators for a rather immersive experience that predates PowerPoint by several decades. The counter-countermeasures manual looks to have the same format as the ones we used for training on Minuteman. PS Good choice on the discone, they are a great broad spectrum receive antenna and pair nicely with a scanner. This antenna type works great for terrestrial / aviation but with it's low 'take off angle' means it looks toward the horizon and doesn't look up very well so it is not a good choice for any satellite / ISS / space comm.
I mount my sdr receiver on the pole right after the discone and use a long USB cable down to the radio room. That way, there is no coax cable signal loss which just adds to the noise figure of the receiver !
Nice fix up. How many watts are those giant brown resistors rated at? You could try tuning the discone at the shack end you might be able to enhance certain bands with a decent tuner. As high as possible is usually best with those. Some other things you could try are modifying certain element lengths for the bands you want and or looking at the discone on the vna to try to get a better idea of where it resonates best.
Discone is vertical polarized I think... also, low sky angle... not good for ISS etc! Egg-beater antennas are better for omni space stuff... for vertically polarized EMCOM discone is great. I would have liked to have seen a closeup of the front panel of the old tube receiver... I could pause the video and peruse it at will... without that info I'm at a loss. Fun stuff though.
Greetings, That looks like a Cushman Electronics MCM-5..... Which I believe was an early offering from Cushman Electronics of a multi channel service monitor. Thank You for the video. 73, JR
Gabe, I would appreciate it if you compiled the comments you get for the Tram 1410 into one video. It was the most common antenna on amazon and bought it. Thanks for all you do!
Another way to fix FM harmonics is move somewhere with barely any broadcast band stations. I moved to the middle of nowhere last year and that fixed that issue. I also have a tram discone and hope to actually get it on the air next week and see what I here. There are a few analog fire and police frequencies nearby and even a trunked system in the next county over. Nearest tv station is almost 90 miles away so no worries there at least. I get 3 or so fm broadcast band stations and none are super strong.
I don't know much about the old radio. But I do wonder if it is AM only? Trying to use it for FM stations, would give audio for strong stations, but that's about it. I also wonder if you could use the HackRF as a signal generator to find the tuning range of the older radio. I'm not surprised at the discone performance trying to get 2M SSTV. The QFH that you used in the previous ISS SSTV video (without the SAW Bird) should work well. Good luck.
Cool video - i hope you find out more about the old radio - it looks very cool - esp with the valves in it - probably good to find out more and not turn it on and off too much as to protect the valves tho. Ironically I have just blown up my HackRF :( Now back on another SDR - will see if I can get the HackRF repaired, its a capable and brilliant SDR esp with GNU Radio companion - just as you said - watch the settings and blow it up.. :(
The ranges on the resistors and capacitors have probably floated out of range. It happens in old electronics. I have repaired many tube amps just by swapping the caps and resistors out. A 1k resistor can float outta range and it will become a few Megs over time. Same kind of thing happens in capacitors.
Yeah, you're definitely going to need a scope. It is how you determined your frequency. It's a simple setup. I am amazed you haven't screwed around with one yet.
I have several SDR radios and a Ham it Up converter, I want more toys I just don't have time to play with them right now. I'm thinking since buying a house 15 minutes from Lake Superior I could pick up a lot without all the interference from cities. One day I might bring a laptop and the radios up to the lake and see /hear what's out there. Probably a lot from Canada? Maybe.
Might not be on the nooelec version but I'm pretty sure my Great Scott Gadgets hackrf has an internal LNA that can be turned on and off using software. Edit: ohhhh you just mentioned it :)
I haven't watched more than 2min of the video yet. Congratulations on buying a 1973 paper govt power point presentation. I love my hackrf one also. Where'd you get the case though? When I got mine in 2014 it was PCB only. Bring the voltage up slowly with a rheostat. Holy smokes! Straight into the wall V? Seriously, bring the V up slowly on old gear. Harbor freight makes a good rheostat for this.
*_Seriously disappointed_* you didn’t invest any prep time to making a video about cleaning up & operating the analog receiver. It is sooo much more interesting than yet another Noolec video, keeping mind there are hundreds of them on TH-cam from some highly skilled operators.
I couldn't find much about this specific one. There are manuals around for other MCM models, but not this guy. Without a manual I didn't have much to go on.
I have a few boat videos and lots of ongoing projects. There's an airboat in the garage that I need to un-bury, an old jet boat that has the drive being rebuilt... outboard skiff and a few smaller boats. I need to get one of those antique outboards working and stick it on a catamaran thing that's also an ongoing project!
You should be getting a better image with that audio. However, Discone antennas have a generally downward radiation pattern at resonance and are probably lousy with the sats
i would see in that radio if any tube is not working, because it can happen due to impacts or the time, bad seals, or shorted tubes! For the first turn on after long time i prefer a 60 or 40 watt light bulb that lower the currents
That isn't a spy radio It is a Cushmman MCN-5, service monitor to test business radios. Even with the ctrystal they were typically turned on 390 minutes or longer to reduce deiift. Muti frequency is due to the individual crystals. It looks like it ws used both for two way communications, as well as remote monitoring of substations and large switch gear. I have several newer versions, along with the Calibrator. You can test the frequency and deviation of FM busibess radios, which weren't very good in 1970. Why don't you ever post the model number and brand of old rest equipment, like this? You could also have crystals cut for local Amateur repeaters, to monitor them. Newer test sets include CCTS signal generators for testing receivers.
Don't feel bad! I get most of my stuff at garage sales, the local surplus store, sometimes dumpsters... lots of neat junk out there for cheap/free if you look around :-)
Please please please. Try Cubic sdr. Hack rf one has a known fault where it creates a false signal on frequency. Cubic sdr has an offset function to avoid it ang get far far better sensitivity. As for blowing up the inbuilt amp and tx output. 1.8? Volts on the antenna will kill them, they are a simple replacement. It makes no difference if the amp is enabled or not. That voltage will kill it. You can put two diodes back to back if you are worried, that will clamp it to roughly 0.5v p-p Also, If you play with the samples per second and the “oversampling” you can really pull out weak signals by dropping the floor with averaging.
![[MV] A leap of faith...ความเชื่อใจครั้งสุดท้าย (From "Petrichor the series")](http://i.ytimg.com/vi/U1piZH2CNXA/mqdefault.jpg)
That radio is a Cushman MCM - 5. Radio repair text into measure signal strength
... I would reach out to Mr Carlson's lab on TH-cam and see if he couldn't give you some information or possibly do a restoration.
restoration from mr carlson is one of the gold standard for restoration
I love how hobby radio is like just 75% attachments and adapters
Mr. Carlson's Lab: ((Heavy breathing))
LMFAO
I was going to suggest watching Mr Carlson if he didn't know of him. What a resource
@@fullmetaljacket76 I was going to suggest he collaborate with Carlson. They could both make videos about it for their channels. :)
@@Pertinacissimus That's a fantastic idea, kind of an old vs new approach.
@@Pertinacissimus That would be pretty awesome.
Fun video, Gabe! The radiation pattern of a discone is narrow in the vertical plane, so it doesn't receive signals from above well. You'd probably do better on those ISS SSTV signals using your NOAA weather satellite eggbeater antenna.
Hope you get some use out of the 'Spy Camp' radio! I wonder what its history was?
I've been watching enough shango066 to know that you NEVER power up an old piece of electronic equipment (especially one with vacuum tubes) unless you test the capacitors to make sure they aren't shorted. Things can get very explodey if you just pound some electrons into it without knowing its condition.
or the non-invasive method: just power them up with a current limiter like a 60w lightbulb in series with the live.
Good to know. Thanks for that input. I have a shortwave radio I need to restore and I have a lot to learn.
Bring the V up slowly with a $15 rheostat.
Came down to say this but have never used the lightbulb method, good idea!@@francistheodorecatte
I think this particular one was sold as "tested, turns on", so I knew someone had already plugged it in recently.
FM notch filters only provide about 15dB of suppression. So if they're on the downstream (gain) side of an amplifier, they don't do that much--the signals "seen" by the receiver will be roughly similar to what you'd see without your LNA. When I was doing APT experiments about 8 years ago, I had FM-notch, amplifier, cable, radio. Also, an LNA is *useless* if it's right next to the receiver--or to be more precise it's no longer an *LN* Amplifier. The noise figure of the LNA is added to whatever losses are ahead of it, so you always deploy them snuggled right up to the antenna. Your FM notch filter will have a small amount of loss outside of its suppression band, but can still be usefully used ahead of an LNA.
2nd this as a qualified ham.
If there's a few particularly strong interference sources you could look at notch filters. Vintage computer people might get mad at me for this, but if you can find a load of surplus 10base2 RG-58 network cables and BNC tee adaptors for cheap, you can use shorted stubs of coax in parallel with your receive line to very selectively "notch out" offending channels. You'll need a tee adaptor and a BNC cable "stub" of a certain length shorted at the end for each channel you want to filter out.
You want to first filter out the strong FM bevor you send the signal to the LNA so it does not get overlaoded. And you want both as close to the antenna as posible that way you have the strongest posible signal for your LNA to amplifiy
That Cushman is definitely older than the '80s based on the style and tubes, and might have been designed much earlier than the '70s even. Appears to be a bench unit for testing radios. Maybe one of those long running products.
I'm pretty sure they were making solid state equipment in the 70s.
This video is definitely one of those videos for people who like taking things apart and looking inside them Just to see how they work.Thank you for showing us all the neat little Do dads that live inside of old technology. keep continuing to make these videos so that we may enjoy them for the rest of our lives
one of the things ive noticed as a non radio guy tinkering with sdrs: ADS is one of the easiest things to receive! Even without a dedicated ADSB filter anywhere, I can get 30 or so adsb hits in any 10 second period. Nothing beats having the transmitter fly over you, even if your antenna is supposed to have a null pointing up.
I listened to a whole lot of 60 and 49 meters through a discone antenna set up inside of a ground floor apartment. Sometimes common wisdom can get in the way of a good time. Thanks for the video.
Hey, Gabe. The biggest problem with that discone is it's pattern. Those elements are designed to give a low take off angle for listening to ground stations, plus a small amount of gain making . Throw together a dipole for comparison. Sweeping it (or any antenna) with a VNA will give more answers, so don't stop with just measuring SWR Also look at the return loss to know the antennas efficiency. Hams and other hobbyists think that SWR is the holy grail, but it's just the beginning of the quest if you choose to travel far on that road.
The QFH antenna is designed to interface to a rotating signal if you will. I'm not sure how well it will work with a static signal, but there will be some loss.
You figured it out, the reason you see so many harmonics is bc SDR's of this type do not have any filters whatsoever, while band specific receivers (and transmitters) have band/low/high pass filters built into them.
The filter is only capable of taking X amount of signal out, and you also learned this by putting the filter before the amplifier. The losses through that filter (which you could also measure with a VNA) are negligible compared to the noise not filtered out by the filter.
The Spy Camp radio may have a bad stage in the front end, which would be why you can only hear maybe the strongest FM station. Look at the caps in it, and if they have any that are leaking, are wax, or don't look like modern devices then replace them with the same values. The only exception are the domino caps, those usually last forever but test them anyway.
Thanking you most kindly from English England
As opposed to the parts of England that aren’t as _English_ as they used to be ??
I've enjoyed seeing that XPS 13 L322X rocking Linux Mint in several of your videos.
Still works pretty well for a second-hand donation :-)
That Crushman would undoubtedly be a very good performer... if it were restored and aligned. Unfortunately I tried to find a manual to link to you and couldn't find one. You're probably going to have to go over it looking for drifted-to-out of tolerance resistors, failed capacitors (be especially mindful of electrolytics outside the power supply section). And then you'd need someone with a good quality tube tester like a TV-7 or Hickok 539 for all of those tubes. Even in 1974 tubes were on their way out, the look & feel of the thing is more late 1950s/early 1960s (that blue-gunmetal-grey was big around then- see gear made by Hammurland, Heathkit, Hallicrafters from that era and you'll see how popular it was around then). Done properly, the higher end tube stuff should blow most modern stuff out of the water but you're not going to find a lot of high frequency coverage in that era of gear. My Hammurland HQ-180 blows the pants off of my SDR stuff for anything below 35 MHz.
As a proprietor of may tube devices, my oldest from 1925, this is the answer.
😃I like your videos because they are accessible to almost everyone, you can see that there is a lot of passion and self-learning, experience nowadays is a rare thing, today enthusiasts are less and less, but there are many professors who study on google and youtube and then teach with zero experience and do tutorials.
With a professional SDR like a sdrplay RSP1B or RSPduo, you would have no problem with external filtering, they are 14-bit SDRs with built-in filters, so today they are the best choice between cost and quality, they are another planet compared to the cheap ones with 8-10 bit sampling without filtering, to do what you do even the nooelek with external filters is fine,
my disk is a Sirio SD 1300 N
RX: 25-1300 MHz
TX (ROS ≤2): 49.5-50.5, 120-180, 215-300, 415-465, 610-650, 710-1000, 1130-1300 MHz! TOP
The book feels like a workbook to go with a class. The book's stock number might help.
Try a whisk or eggbeater antenna for overhead passes. That might give you better high angle reception.
A very beautiful tube device; with a little care, it will work like new again. I love these devices; they are very sturdily built and will most likely survive any EMP. The antenna is really good-I used to use one like it in the past.
Dude, I don't even remotely possess the knowledge to do any of this, but I watch and marvel. Wish I had a neighbor like you 🤘
SDR receivers are a neat toy which allow you to hear a wide range of frequencies, but they have very poor Selectivity and also cannot handle strong signals.
The add-on filters are needed because the manufacturers have left out the critical RF filters that you would find on a more expensive receiver.
One thing the SDR's do have is a fairly high Sensitivity, which means that they can hear fairly weak signals. The down-side of Sensitivity without adequate Selectivity, is that the stronger stations (eg Broadcast FM) will cause overload and give spurious signals right across the dial.
The basic rule of RF designers is "Coils before Transistors" (eg "Selectivity before Sensitivity"). The problem is that Transistors are cheap, while Coils and Filters are expensive. Once your design allows strong signals to overload the set, you have lost the game.
To improve your SDR, one of the most useful things is an adjustable attenuator. If you see FM stations everywhere, your are into gross overload and cross-modulation, so you need to greatly reduce the gain so that no longer happens.
Gabe: It looks like the MCM-5 is a piece of test equipment, not a general-purpose radio. It operates on a few specific frequencies, defined by a set of crystals in a crystal oven. The table on the inside cover shows you the frequencies available for that unit. The selector knob lets you choose between those frequencies.
Use the ZERO FREQ. ADJ. function and knob to tweak the operating frequency, probably by comparing the CRYSTAL OUT signal to a reference. (I used to use WWV for checking a frequency counter.)
If you're testing a transmitter, you can use the MCM-5 to check different parameters, selected by the knob at lower left.
SIG. LEVEL appears to be pass/fail, shown by the green scale second from inside on the meter.
To see how far off the transmitter carrier frequency is from the reference, use the "CARRIER FREQ." mode and the two outer scales of the meter.
To check the peak FM deviation, use the 18 Kc or 6 Kc. FM DEV functions and the red scales on the meter. (IIRC, FM broadcast uses 100 kHz deviation. 18 and 6 kHz are "narrow band" FM, for communications equipment, rather than high-fidelity music.) The "FM MOD. PEAKS" switch allows you to check peak positive or negative deviation from the carrier frequency.
The SIG. GEN. function allows the unit to produce a signal for testing receivers, with the SIGNAL OUTPUT ATTENUATOR selector switch and pot adjusting the level (albeit uncalibrated).
I don't know what the HARM. AMP TUNE function and knob do, nor the (apparent) ten-turn pot for GEN. LEVEL SET.
I am currently listening to a podcast called "lost terminal", and it mentions a lot of radio related stuff (vhf, satellite, etc); i'm slowly understanding what they are thanks to your videos haha
Looked it up. I like it. Thanks for mentioning it.
I live to hear "Hi! And welcome back to the saveitforparts channel"
The position of the filter at first make sense for me : if the filter reduce, let say, 3dB, on weak signal, it could be send to noise level. If put after amplifier, you already amplified harmonics and fm signal, for, let say, +15dB, so you just removing 3dB on a strong signal
My fave radio when I was a pre-teen was a Stromberg-Carlson AM/FM receiver, designed in the 1950s, and we got it from a nabe who was unloading a bunch of things. Tubes, of course. I still had it into my late 20s...... I also had a Hallicrafters multi-band shortwave receiver--similar vintage. Now, they are rather more rare, and when you can find them, they often fetch a pretty penny....
Discones often have a vertical element that improves the VHF-and-lower performance.
The main issue with the discone for trying to receive from the ISS is that the discone is great for low angles. It's exactly the wrong antenna for talking to satellites, which are both way above the optimal angle and also circularly polarized.
That's why you had better results with a dish - you could point it more easily.
They're also fairly compromised. A jack of all trades, but not very good at any of them.
@@cottonfoo The one thing they absolutely excel at is bandwidth, which in some cases is exactly the thing you need. Especially if you want a 'works well for any band' SWL antenna that has no active components.
Verticals are not good at copying the ISS. Consider the radiation pattern. There is a huge null on the vertical axis. Think of the pattern as a doughnut. Up is the hole.
What a neat machine that wide-band receiver is!
That book looks like its slides from a presentation.
that 70's radio is a version of a Radio service monitor way cool.
since the Cushman uses crystals to set the receive frequency, you will really only be able to receive stuff on those frequencies. You could replace one of the crystals with a DDS (direct digital synthesizer; a single chip sort of thing, controlled buy a microcontroller) and this would allow you to tune across the range of the DDS rather than be locked to a single frequency
That is a service monitor. Used to align two way radios.
Thanks Gabe, always interesting!
Two things. I think you have the baby Discone antenna. I remember there being two sizes available when I considered getting one and one was quite a bit bigger than yours. I also remember the larger being the one to use on 6 & 2 meters.
Second, I have the SDRPlay RSP-1 receiver and I never have trouble with 2nd or 3rd harmonics showing up elsewhere such as FM broadcast signals. I wonder if its a matter of not having filters in the receivers your using.
Bonus, the antique which looks late 60's to me looks very interesting. Toss it to me if you need to save space, but yes, restoration would be a good idea for it likely has bad caps and perhaps out of spec components now.
If nothing else. That old boat anchor sure does look cool.
Love the shirt!!!!! The Give up one.... Well, all of them are great!!!
I think that one is from Obvious Plant, who always has fun products!
I’d buy that antenna just to put it on my flag pole, it looks so cool! Keep it up there!
I constantly snoop on VHF because the cops in my major metropolitan city pirate 150 to 160 MHz for chit-chat and they're a blast to listen to. I have an old 5/8 wave 2m vertical at 25 feet and a Radio Shack PRO-2006 with a computer interface. I run an awesome program called Probe to control it. The selectivity and sensitivity of the 2006 beats the pants off any SDR I've tried.
Most discones have a center element that sticks out the top... does yours not have one, or did it not get installed? If it's missing, that would explain why it's not very good at VHF...
I think he got the one without it. I got tripped up by that on amazon too when I went to order one. I think he got the 1410 without the VHF, the 1411 is $10 more and has it.
No, not all discones have an element above the disc, I have one, no upper vertical element and it receives just fine on VHF.
@@NickDelDuca "Without the VHF"????? 25 MHz to 1300 MHz is VHF to UHF (with the very upper portion of HF thrown in), and that's what the Tram 1410 shows for frequency spread, and looking at the 1411, there's a LOADING coil at the base of the vertical element and it's for CB which is NOT VHF. I use mine to transmit and receive on 2M, and that IS VHF.
The vertical whip is an add-on to enable a VHF/UHF discone to hear signals below 30MHz, It basically is a bottom loaded 27Mhz antenna.
And to enable that, most have a 3/8"×24 threaded socket on top with a bolt or cover threaded on.
I always like how you call things "not effective or useful" based on you not knowing how to use them, or antennas not working well based on you using long pieces of the worst coax known to mankind with 500 adapters on the end. That's a very recurring theme on this channel
You could use the nooelec to do frequency sweeps to figure out how the older unit frequency ranges work on the spy camp box....
I have a discone antenna as well, it's up at the 6 mtr pole, ofcourse the higher the better. But for satellites it doesn't work very well because when there is a high pass the signal fades away, you probably need a horizontal antenna of atleast something with a wider angle if that makes sense. Weather balloon reception however seem to work decently. As for local (air) traffic or FM radio or 2 mtr/70 cm it's all fine, yes you can do much better but you'll need a frequency tuned antenna with more gain but this does everything a little.
Discone is perfect for an old school scanner. If you get one that will do 27mhz and 800 trunked at once then you will have cb and police all on one antenna.
In the 70's the Air Force used a unique 'multimedia' format that combined slideshow, 16mm film and simulators for a rather immersive experience that predates PowerPoint by several decades. The counter-countermeasures manual looks to have the same format as the ones we used for training on Minuteman.
PS Good choice on the discone, they are a great broad spectrum receive antenna and pair nicely with a scanner. This antenna type works great for terrestrial / aviation but with it's low 'take off angle' means it looks toward the horizon and doesn't look up very well so it is not a good choice for any satellite / ISS / space comm.
I mount my sdr receiver on the pole right after the discone and use a long USB cable down to the radio room. That way, there is no coax cable signal loss which just adds to the noise figure of the receiver !
I've had trouble with extra long USB cables, the un-powered ones can't run an SDR and Bias-Tee, and the powered ones add extra interference.
@@saveitforparts Yep - nothing is ever simple !
Nice fix up. How many watts are those giant brown resistors rated at?
You could try tuning the discone at the shack end you might be able to enhance certain bands with a decent tuner. As high as possible is usually best with those. Some other things you could try are modifying certain element lengths for the bands you want and or looking at the discone on the vna to try to get a better idea of where it resonates best.
Discone is vertical polarized I think... also, low sky angle... not good for ISS etc! Egg-beater antennas are better for omni space stuff... for vertically polarized EMCOM discone is great. I would have liked to have seen a closeup of the front panel of the old tube receiver... I could pause the video and peruse it at will... without that info I'm at a loss. Fun stuff though.
Greetings,
That looks like a Cushman Electronics
MCM-5.....
Which I believe was an early offering from Cushman Electronics of a multi channel service monitor.
Thank You for the video.
73,
JR
Time slot: (15:47) morse code (aka CW) was N0BVE/R from Minnetonika Minnasota. I believe it was one of his repeaters?
Someone else who decodes CW on YT videos
You get some good stuff on your new radio scanner
Most fascinating channel on TH-cam
Gabe, I would appreciate it if you compiled the comments you get for the Tram 1410 into one video. It was the most common antenna on amazon and bought it. Thanks for all you do!
If you had a big enough room that antenna would look really cool strung up in the air
Another way to fix FM harmonics is move somewhere with barely any broadcast band stations. I moved to the middle of nowhere last year and that fixed that issue. I also have a tram discone and hope to actually get it on the air next week and see what I here. There are a few analog fire and police frequencies nearby and even a trunked system in the next county over. Nearest tv station is almost 90 miles away so no worries there at least. I get 3 or so fm broadcast band stations and none are super strong.
YES YES YES CONTAC MR CARLSONS LAB !!! WILL BE GREAT COLABORATION THANKK!!!!
That is "Death by powerpoint" in print form lol.
This is definitely from the early to mid 60s or older, by the 1970s tubes were finishing being phased out of new components.
you might try a wide band log-periodic yagi antenna to avoid lots of noise and beam to weak signals, the best amplifier is still the antenna
I don't know much about the old radio. But I do wonder if it is AM only? Trying to use it for FM stations, would give audio for strong stations, but that's about it.
I also wonder if you could use the HackRF as a signal generator to find the tuning range of the older radio.
I'm not surprised at the discone performance trying to get 2M SSTV. The QFH that you used in the previous ISS SSTV video (without the SAW Bird) should work well.
Good luck.
Cool video - i hope you find out more about the old radio - it looks very cool - esp with the valves in it - probably good to find out more and not turn it on and off too much as to protect the valves tho.
Ironically I have just blown up my HackRF :( Now back on another SDR - will see if I can get the HackRF repaired, its a capable and brilliant SDR esp with GNU Radio companion - just as you said - watch the settings and blow it up.. :(
In addition to reaching out to Mr Carlson's Lab, you should chat with Ringway Manchester about radio scanning. :)
I do enjoy Ringway Manchester's videos :-)
The ranges on the resistors and capacitors have probably floated out of range. It happens in old electronics. I have repaired many tube amps just by swapping the caps and resistors out. A 1k resistor can float outta range and it will become a few Megs over time. Same kind of thing happens in capacitors.
I never had good results with that antenna except in the CB band.
Yeah, you're definitely going to need a scope.
It is how you determined your frequency.
It's a simple setup.
I am amazed you haven't screwed around with one yet.
I have a 1940s scope with about 3 controls... still don't know how to use it 😂
I have several SDR radios and a Ham it Up converter, I want more toys I just don't have time to play with them right now. I'm thinking since buying a house 15 minutes from Lake Superior I could pick up a lot without all the interference from cities. One day I might bring a laptop and the radios up to the lake and see /hear what's out there. Probably a lot from Canada? Maybe.
12:36 as a Brazilian, I couldn't understand a single word 😂
Hi you should get that antenna on a metal pipe and ground it it should take more noise off that way
Might not be on the nooelec version but I'm pretty sure my Great Scott Gadgets hackrf has an internal LNA that can be turned on and off using software.
Edit: ohhhh you just mentioned it :)
Looks like a 1960s design to me. Possibly even 1950s. Transistors became much more prevalent starting in the 1960s.
Thank you Gabe Another awesome video really enjoy the radio videos 73 from kf0myu
I haven't watched more than 2min of the video yet. Congratulations on buying a 1973 paper govt power point presentation. I love my hackrf one also. Where'd you get the case though? When I got mine in 2014 it was PCB only. Bring the voltage up slowly with a rheostat. Holy smokes! Straight into the wall V? Seriously, bring the V up slowly on old gear. Harbor freight makes a good rheostat for this.
You have a good t shirt collection.
Those pieces that felt are the plug lug nut and washer. Just screw it back and be gentle with the tork.
Discones are cool! Good for 2m and 70cm TX too.
Right on!!
It was very interesting
A discone antenna has low gain straight up. And a tunned antenna pointing in the correct direction would be better.
The brown circular object at 3:56 … Backing nut for oscilloscope jack?
Maybe so! That part was a little broken.
*_Seriously disappointed_* you didn’t invest any prep time to making a video about cleaning up & operating the analog receiver. It is sooo much more interesting than yet another Noolec video, keeping mind there are hundreds of them on TH-cam from some highly skilled operators.
I couldn't find much about this specific one. There are manuals around for other MCM models, but not this guy. Without a manual I didn't have much to go on.
That box is the print version of death by Power Point
Yeah, i have too pair old milcom radios, they cool.
Biconical antenna better because radiation pattern not depend from frequency.
I'd prefer that old reciever day and night above the Hack RF, and would pay Hack RF $$ for it! Woul be great for SWL!
Make sure your compressed air source is got a way to remove the water from the air coming out nozzle
The
Zoinks..
MY favorite stuff to um, collect...
2 Christmas 🎄🎁 present 🎁 all ready you have been lucky
I spotted some stuff in the background. It looks like you're also collecting outboard motors. Do you do any boating other than the sandbox toy?
I have a few boat videos and lots of ongoing projects. There's an airboat in the garage that I need to un-bury, an old jet boat that has the drive being rebuilt... outboard skiff and a few smaller boats. I need to get one of those antique outboards working and stick it on a catamaran thing that's also an ongoing project!
That was fun. 👍
You should be getting a better image with that audio. However, Discone antennas have a generally downward radiation pattern at resonance and are probably lousy with the sats
You can add some gain to the signal here, too, get it way above the nose floor.
keep up the good work...
i would see in that radio if any tube is not working, because it can happen due to impacts or the time, bad seals, or shorted tubes! For the first turn on after long time i prefer a 60 or 40 watt light bulb that lower the currents
That isn't a spy radio It is a Cushmman MCN-5, service monitor to test business radios. Even with the ctrystal they were typically turned on 390 minutes or longer to reduce deiift. Muti frequency is due to the individual crystals. It looks like it ws used both for two way communications, as well as remote monitoring of substations and large switch gear.
I have several newer versions, along with the Calibrator.
You can test the frequency and deviation of FM busibess radios, which weren't very good in 1970.
Why don't you ever post the model number and brand of old rest equipment, like this?
You could also have crystals cut for local Amateur repeaters, to monitor them.
Newer test sets include CCTS signal generators for testing receivers.
I showed the model number on the back at some point in the video. I haven't been able to find a manual for it, just for different models.
you have such cool shit I only watch you now when I wanna feel bad about myself
Be Well
Don't feel bad! I get most of my stuff at garage sales, the local surplus store, sometimes dumpsters... lots of neat junk out there for cheap/free if you look around :-)
Love your discone
Utility radio band's
Please please please.
Try Cubic sdr.
Hack rf one has a known fault where it creates a false signal on frequency.
Cubic sdr has an offset function to avoid it ang get far far better sensitivity.
As for blowing up the inbuilt amp and tx output.
1.8? Volts on the antenna will kill them, they are a simple replacement.
It makes no difference if the amp is enabled or not. That voltage will kill it.
You can put two diodes back to back if you are worried, that will clamp it to roughly 0.5v p-p
Also,
If you play with the samples per second and the “oversampling” you can really pull out weak signals by dropping the floor with averaging.
Try your satellite work with the antenna upside down.
Buy a SMA torque wrench to save your SMA connectors
Be careful with that lid off, mam. Tube PSUs are deadly.