My 630M Adventure - Part1

[@nigelbrockwell6237]

I worked for Marconi Instruments in the UK for 30 years, so I will be listening out for signals during that Marconi anniversary.

[@MIKROWAVE1]

We have a big snowstorm tonight and a bit of noise but I hear stations working good old CW on the band.

[@ellise.2574]

Hi Mike. For a receiver I am going to try using my BC-348-R and my BC-453. Both will tune down to 630 meters. I may also try winding a pair of coils for my National SW3 regenerative receiver. Looking forward to seeing what you come up with for a transmitter, and an antenna. I always enjoy your channel! Thanks.

[@MIKROWAVE1]

Yes those old radios both cover the band and are worth showing up in a video! But it really is all about the antenna.

[@ricke.2205]

Standing by, Mike. Looking forward to the next video. 10 tubes, wow!

[@Steve-GM0HUU]

Thanks Mike. Definitely signed up for this new adventure. In the UK we have access to 630m with 5W eirp (secondary basis, full licence and some restrictions). I was trained many years ago on MF marine transmitters that worked around the old CW marine 500KHz distress frequency and calling channel. These were Marconi sets which used thermionic valves rather than these "toobs" you were talking about 😁. So, would be very interesting to get on the air on this band - especially with the weak signal digimodes we have nowadays and some CW of course. The Marconi Salvor III is one that I remember. One of these with a little VFO mod for 630m would be nice? It even has a built in morse key and a very impressive variometer for antenna matching.

[@oilydigits]

Steve Are you aware of the rsgb lf group? They are very active on both sides of the pond. 73 Steve M0KOV

[@Steve-GM0HUU]

@@oilydigits No I was not. I have just applied to join. Thank you.

[@claycoates5056]

Looking forward to see this

[@clytle374]

Interesting, 630 and 2200 meters is on my list of things to play with someday

[@MIKROWAVE1]

I'm finally hearing things on 2200m. That is another nut entirely.

[@walterbrown8694]

First tube type receiver I ever built was a regenerative single tube broadcast band receiver, built over 70 years ago with second hand tube, rf coils and other radio parts. Didn't have my Ham license in those days, and I had to be careful operating it because carelessness in tuning could result in it becoming a low power transmitter to other radios in the house. Fortunately I never got any complaints from neighbors, or any notices from the FCC.

[@MIKROWAVE1]

So the snooper truck never came by your neighborhood!

[@GolerGulch]

Well done on your construction projects Mike. I live in Simi Valley (next door to the San Fernando Valley aka LA county) and there are 3 of us that meet twice a week on 476 KC using USB. I using a modified Heahtkit HW-18 Transceiver into that BC306 antenna tuner with a 40' vertical with an inverted L. Were running somewhere around 150 watts and I have NO ground radials, only the water pipe and am heard quite well all the way to Burbank,Ca with a strong signal (my house was built in 63' so all the pipes are iron which connects to the city main which is also metal so that's what is doing the heavy lifting) . When we get our spring rains I can start laying ground radials. Both of the guys on with me are using Transverters and are putting out 200 watts to overcome that massive QRM. I am using 2 DSP noise cancelling units in series to deal with the noise as I have a 18KV powerline in my backyard.

[@MIKROWAVE1]

Wow that is an awesome conversion!

[@mohinderkaur6671]

The Audio amp section of 12au7 can be reflexed as a rf amp for isolation. On 630M a Class E using 1000v mosfets running off halfwave rectified mains voltage also is a great option

[@MIKROWAVE1]

Class E is the modern efficient Standard for many experimenters here on 630M. My valve approach was quite a deviation from the norm today. As is Reflexing. Wow that is an old fun area to explore.

[@georgegeorge6442]

VERY GOOD!!!

[@kensmith5694]

Something I discovered many years back on crystal radios is: A wire running around the house could be brought into resonance by treating it as a big one turn inductor. When resonant, a wire off one side of the capacitor made a much better antenna than the wire without the tuning capacitor. The tuning of the antenna was quite low Q

[@MIKROWAVE1]

Generally a shorted loop is less prone to close coupled noise because the electric field pickup is somewhat reduced, and its impedance is lower in most cases.

[@kensmith5694]

@@MIKROWAVE1 In my case, noise wasn't the issue. It was signal amplitude I was after. This was a crystal radio. A symmetry argument suggests that an antenna that works better to receive RF power should also be better to transmit power. BTW at the lowish frequencies involved in this band, there are tricks that can be done to make the RF output stage recapture the energy from the reactive component of the load. The simplest version only works with inductive loads. Consider how a buck regulator works to see this.

[@AlreadyThere1965]

I can't wait to see what you come up with for an antenna.

[@berndb.5097]

I agree with you, I would use tubes for 630m in particular. I couldn't think of anything else. 🤩 73 de Bernd

[@MIKROWAVE1]

Totally Tubular Bernd!

[@berndb.5097]

@@MIKROWAVE1 Totaly Tubularish :-))

[@acmefixer1]

It's odd that the regen was supposed to use a 12AU7 but the shot from above it looked like an octal tube, maybe a 6SN7? It had no evacuation pip sticking up like the 12C5. I've got another question about the B+ but I'll have to go back and look at the schematic.

[@MIKROWAVE1]

Um I checked and it was a 12AT7. We were both wrong. Ha. Actually a 12AU7, 12AT7, 6SN7 octal etc. would work equally well in this circuit.

[@StaryiPatefon]

Отлично мой друг 🤗👍👍👍👍

[@MIKROWAVE1]

Все дело в антенне.

[@theshannonlimit1114]

for all those who can't afford a wj, racal, aor etc. but who don't want to build something, look for old selective level meters.

[@MIKROWAVE1]

Yes those are spectacular LF receivers!

[@U812-k7j]

I use a RAL receiver with an ART-13, CU32 antenna coupler. VERY noisey operation lots of relays clicking away at one time.

[@MIKROWAVE1]

My friend KW1I put an ART13 and RAL on several years ago during the experimental phase of getting us a new ham band.

[@540Baseball]

Nice to hear Mark Levin in the background…

[@MIKROWAVE1]

AM is making money and has been saved by talk radio!

[@DAVIDGREGORYKERR]

What about a 9:1 UNUN using heavy duty enameled wire that can take the high power output of your transceivers.

[@MIKROWAVE1]

You are skipping ahead again David. Ha.

[@sylweksliwka7986]

👌👌👌

[@MIKROWAVE1]

Czy masz uprawnienia 630m? Prawdopodobnie tak w euro. Byłem kiedyś w Warszawie w TVP. A raz do Wilna. Wielu świetnych radioamatorów.

[@sylweksliwka7986]

@@MIKROWAVE1 przykro mi ale nie

[@Mold0vanin]

Спасибо. Познавательно.

[@MIKROWAVE1]

Спасибо за просмотр моих радио-видео. 73's

[@itsonlyme9938]

How about a BC221 wavemeter as a vfo ???

[@MIKROWAVE1]

Now yer thinkin! That would work beautifully.

[@MrValera585]

it's a pity that this band is not allowed in Russia

[@MIKROWAVE1]

Wow that is a shame.

[@perherbert]

Not junk it's recycled equipment. 👍

[@MIKROWAVE1]

Yes! and hams are not cheap!