Удивительная схожесть схемотехники НАТО США СССР )))) Прям копия))) Прям мы не рабы и это все не театр))

Believe me or not, after watching this video, I went on ebay to check the item, considering to grab one of them.. and I checked the other things from the same seller. I found and ordered.... a satellite part 🤯! UV detector head for 1967 Ariel-3 british satellite ! Video about it on my channel in 2-3 weeks I hope, meanwhile I have done 2 posts about it.

Thanks, saved me my 3303C

I get an error trying to add the radio with chirp “radio returned unknown identification string” are you able to add a fix for this as have tried researching but get nothing Cheers Murray

Piekny PA

i would love one of these, i would suss out every aspect of it & attemp to rig a controle panel to it & get it up for a test, i bet i could suss it given a few days

Thanks for this Teardown. This is a rack-mount unit that was likely used onboard an aircraft for UHF transmission

these are utter cheap crap. frequency counter are always off and unstable. PSU blows easily as no crow bar protection or over load protection. the function generator is well off to twat the display says, and the multimeter, i wouldn't trust it, i'd trust an Aldi multimeter more.

I hope you will rebuild it again

This looks like an aircraft communications transciever for the UHF aircraft band (225 to 400 MHz), probably designed in the mid 1970's. The power supply looks to be a linear voltage regulation drawn from a 3 phase power transformer. Switching power supplies were non-preferred due to the EMI they generate and high power bipolar switching transistors are relatively slow compared to FETs. The only problem is, I don't see any large bulk filter capacitors. You don't need that much filtering though with a 3 phase, full wave rectifier with a 115 volt, 400 Hz line. The RF power amp (or transmitter) is linear and low level modulated using bipolar transistors. Those hybrid splitter/combiners may be the 90 degree type, which are used to isolate the parallel outputs for reduced distortion. My best guess on the output power is 100 watts CW, with 95% AM modulation capability. DC power needed for the RF power amp is probably 28 Vdc at 20 amps. The receiver probably uses 3 pre-selectors to cover the broad frequency range. Using 3 pre-selectors also reduces the signal level across the varactor diodes, which reduces intermodulation distortion. On an aeroplane with multiple communication transceivers, due to the limited antenna separations, it is common to have an undesired in-band signal of 0 dBm or more. The supposed GaAs FETs are actually bipolar medium power RF transistors. The canned filter nearby is probably a lowpass filter for the synthesizer DC output. The synthesizer appears to be a typical TTL divider type, with a high frequency pre-scaler.

Would you please, "de-quietsch" your chair! - Pleeeaasee ! !! !!! !!!!! !!!!!! - What a 'horrible tone' the seat emmits, when you move on it, a little bit. Unbelieveble !!!?!!! (Or set a 'notching-filter', across the disturbing noise the chair emmittess, ... !) Just for the funy noise, when you 'wiggle 'the chair. 73 de Markus - db9pz - just over the channel, from 'good old Germany', - JN39fq - 5km/3km east of LX -

not frountends! they are VCOs

It Out of a Mil Aeroplane!!!

Hi could you make a video of how to use a Bird 5000-EX with a 5010 sensor?

Does the RF power transistor contain dangerous beryllium?

Funny, ex-military components are supposed to be destroyed and not make it to the civilian marketplace 😮

Can I plug a commodore C64 into it ?

Thank you for your dedication/time going over this unit. Most appreciated.

Hi, my name is Renato, I wanted to ask you if you have changed the battery on the CMS 50 and if you know where to find the wiring diagram, thanks

я вот себе купил CMU 200 но так хочу CMS53 (((

I bought an Anritsu Sitemaster S331 on Ebay a few years ago. It was "for parts not working" and wouldn't switch on, but it came with the padded case, software (floppy disc I think) serial lead, phase-stable patch lead, OSL standards all in the factory supplied peli case. Turns out that the battery had leaked on the PCB in the meter, and had rotted a few traces. Those traces were non-critical logic circuits, so it was an easy fix with some bodge wires. While it was apart, I put a new battery pack together with something like 10x the capacity (runs the meter for weeks between charges). The lovely Anritsu power sensor that came with it all lasted about a week before I connected a UHF handheld radio and chucked 4W up it with no attenuator. The INSTANT I pressed the PTT, I released it and sucked air in through my teeth. Yep - toast. My tip for people working with the same radio gear day in and day out is to put a pair of attenuators on the sensor, and leave them there. The idea is, if you connect a 50w mobile / repeater, the attenuators will scale things to be safe and measurable. If you want to measure a 4w handset, you have to go to some extra effort to remove one of the attenuators every single time. Done this way, you have to go to extra effort to make the sensor vulnerable, rather than having to go to extra effort to make it safe.

Tnx good work

Nice power meter

Czy miernik HP437B posiada baterię litową 3V ? Pozdrawiam

I agree...many a HP power sensor has had the thermocouple, or the diodes, blown into low earth orbit, by connecting them to too much power. It only takes a second, and that's the end of the thermocouple. That includes connecting them to the cal output on the power meters, without the 'reference' attenuator that is supposed to be used with some of them. Long ago, HP used to sell kits, so users could replace them...but that's long ago. If you pop it... it's done. You can't fix it. Many for sale, as for 'parts or repair' The part you most often need for the repair is the thermocouple (or diodes), and that's usually blown in these. Don't buy them.

The older "HP 8485A Power Sensor Operating and Service Manual" and the newer "Keysight 8480 Series Coaxial Power Sensors Operating and Service Manual" have exploded drawings, instructions on how to open the case, and circuit diagrams. And yes, many a 8485 HP power sensor has been destroyed through severing the gold wire(s) connecting the thermocouple ... usually by people who can't be bothered to read the excellent free docs.

Those are APC-3.5 mm connectors, I believe.

I don't see how the gold can "melt" because of soldering. Gold melts at around 2000 F and tin lead solder at about 500 F. Do you mean that the gold dissolves into the solder? HP used to... long ago, gold plate the tracks of PCB. Solder worked fine there.

Great Video, thank you. With the tracking generator I believe you need to use the normalize option this compensates for any losses to flatten the trace.

Hi RFMAN. I am enjoying your video. Thanks. Do you know where I can get a service manual or diagrams for these machines please?

Добрый день Уважаемый автор! Хотел Вам вырозить благодарность! Я недавно нашел CMS200 Rohde&Scwarz стоит подозрительно дешево в раионе 800$ на Алиэкспрессе, вот теперь задумался, стоит ли его покупать.

Also, i wouldnt do anything in the "CLEAR MEM" Menu. This Resets the "AB2 Broadband Power Sensor" Calibration to Default Values. The 2966 isnt able to Correct these values Automaticly. And I haven't found out yet, how to do this manually correctly.

As has already been pointed out bridging pins 1 and 5 with a resistor (my choice would be 5.6K) will restore the bias to the BFR93 transistor used as a signal amplifier in the OM345 where the on board resistor has failed and the module will start working again. This procedure is very easy and quick to do and no messing about trying to build and fit a MMIC amp instead.

What a super video on the 2966a. I think I will be watching this again as there is so much to learn from it. I have a 2966a which I fixed. The PCB connecting to the front panel was misallied and it blew the 5v lin inductor on the top PCB. replaced the inductor and aligned those pins correctly and everything worked again. I think I will be delving into mine again now I have watched the video. Thank you so much

Great video but Not sure why you will not share the hidden calibration menu code? I have a 2966A in calibration but it would be nice to gain full access, even if for documenting values. I am looking forward to your future video of the PSU module removal, with the age of the unit and only a question of time before a Capacitor fail I was thinking of doing a full cap change on the PSU.

Nice...I Repaired a 2966A myself. Are you maybe willing to sell this machine? Or Parts from it? Im especially looking for a Frontend Module, and the Input and Output Attenuators.

I've recently acquired a CMS 33 however it looks like the measured RF power on the TX test section is not correct (looks like its doubled). Would you share the service manual and do you have any hints?

Could you use the one Rigol Oscilloscope to measure both sides of the bridge? Or will that blow up the scope?

Tank you so much for you excellent video. great detail and very helpful in allowing me to repair the unit i have. I really like the idea of using the spec ann to measure the gain of the amps. Super idea. I just bought a 2022 and it was working on some frequencies but not all. Thought it was the OM345s but turned out to be a 100ohm resistor feeding 12v to the VCOs running at 171c as the 220uf cap on the VCO side was a complete dead short. Someone had been in before me and added resistors to some of the OM345s an the others are working ok so far.

So after all, the English textbooks were right that all people in the UK have an orange cat called marmalade.

Can I plug my commodore 64 into the serial port 🤠

Do I need 30 amps for my cobra 138 xlr

does RFMan stand for "read factory manual?

looking for a backup service monitor. how does the marconi compare to the hp 8921a?

Was this the V1 or V2 pcb version of the rt4 70x?

Ojo, parece ser la versión antigua del 470x, o al menos el firmware lo es... comprueba la actualización en la web de Radtel y rehace las pruebas......

Thats a Motorola R2001D model,the last of the R2001 series before the R2600 was released by Motorola The R2001A/B/C were completely different inside from the R2001D series. The R 2001A/B.C modules and cards were mostly interchangeable between them,were as the D was a completely different animal and shared none of the modules from the A-C series The A series was a nightmare to repair and reliability and design slowly got better through the different revisions ending in the D model revision that was a fantastic test analyzer I used one for more than 10 years and it finally got retired due to a dead CRT

Very interesting video of the 2955 repair I worked as a repair tech at a depot that repaired the Motorola series of comms analyzers in the early 90s,specifically the R2001A/B/C and D series and also the baby versions of these, the R2200 and R2400. These Marconi test sets seem to be a lot less modular than the Motorola units as far as the way they were built and designed. We would normally swap out a faulty module or card and get the customer unit back into service asap and repair the faulty module at our leisure at a later stage

Made me dizzy trying to watch this.. try slowing down a bit and keep the camera steady. Couldnt see what you were looking at half the time, moving so fast...73

I like this radio but is there any possibility to turn of the sound , i mean that speech is annoying me... :(