Search found 21 matches

by pioneer
Sun Sep 13, 2015 10:18 pm
Forum: AM Radio
Topic: out-phased modulation
Replies: 9
Views: 1646

Re: out-phased modulation

Yes RCA did that with Ampliphase, they use a some different idea. In this system from Ampliphase is an carrier tube and peak tube, they are switched in parallel. In my idea the outputs from the amplifiers are also in parallel, but for the load in series. The difference in phase is transformed to the...
by pioneer
Sun Sep 13, 2015 8:25 pm
Forum: AM Radio
Topic: out-phased modulation
Replies: 9
Views: 1646

out-phased modulation

Could out-phased modulation give a good efficiency, thats my question. To generated AM you have two amplifiers and supply them with not 180 degrees phase difference but 90 degrees phase difference. Couple the two RF outputs from the amplifiers to ferrite transformers with an parallel tuned LC circui...
by pioneer
Sun Sep 13, 2015 7:15 pm
Forum: AM Radio
Topic: AM ground radial wire size and type ?
Replies: 13
Views: 2485

Re: AM ground radial wire size and type ?

Enamelled copper wire or magnet wire could be a solution because it is protected against corrosion. It could be less expensive than pvc insulated wire and is available on large spools by transformer manufactures. The copper wire could be laid out in loops, at the ends instead of straight wires. The ...
by pioneer
Fri Jul 24, 2015 12:32 pm
Forum: AM Radio
Topic: Gates Transmitter in Storage
Replies: 3
Views: 996

Re: Gates Transmitter in Storage

Nice to see these photo's of this unknown transmitter with the 810's on it.
by pioneer
Fri Jul 24, 2015 12:24 pm
Forum: AM Radio
Topic: AIM Antenna Analyzer
Replies: 25
Views: 5263

Re: AIM Antenna Analyzer

Hi all, I am ordering an AIM 4300DX its preferred over AIM 120 due to limited budget. My question is if I measured the impedance of folded unipole antenna tower via trap(to prevent overloading from nearby station) do the measured impedance is accurate ? also is the static drain coil inside the ATU ...
by pioneer
Thu Sep 18, 2014 6:56 am
Forum: AM Radio
Topic: schematic Collins 828E
Replies: 5
Views: 1455

Re: schematic Collins 828E

Thank you PA tune for your reply, I have sent you a personal message with my e-mail address.

Regards,

Martin
by pioneer
Wed Sep 17, 2014 5:17 am
Forum: AM Radio
Topic: schematic Collins 828E
Replies: 5
Views: 1455

Re: schematic Collins 828E

An mistake occur regarding the type number type what I found on this site: http://www.oldradio.com/archives/hardware/Collins/828E.htm Where the 316R is called, I assume that the type 828E Collins is the right type with 5kW and PWM-modulated. Here I made the mistake because I'm not in the possession ...
by pioneer
Tue Sep 16, 2014 12:24 pm
Forum: AM Radio
Topic: schematic Collins 828E
Replies: 5
Views: 1455

schematic Collins 828E

I am looking for a schematic not the entire manual, of the Collins 828E transmitter or the Continental 316R what is basically the same schematic.

Regards,

Martin
by pioneer
Sun Aug 03, 2014 11:47 am
Forum: AM Radio
Topic: Ground Radial System
Replies: 17
Views: 3958

Re: Ground Radial System

I do not know how effective the pigtail is against lightning, it is nothing more as a single turn of copper tube.
A spark gap is more efficient than a pigtail, normally used both and also a UV detector inside the ATU house.

Martin
by pioneer
Mon Dec 30, 2013 1:25 pm
Forum: AM Radio
Topic: Marconi BD272 transmitter
Replies: 0
Views: 1282

Marconi BD272 transmitter

Here a video tour around and inside the Marconi BD272 broadcast transmitter. This 'mighty beast' was a popular broadcast transmitter what was built in the beginning of the 1960' till 1969. Some of them where used for over 40 years of service by the BBC in Woofferton UK. 456999872_2c2652d071_o.jpg 59...
by pioneer
Mon Dec 30, 2013 1:09 pm
Forum: AM Radio
Topic: Early days of Broadcasting BBC
Replies: 3
Views: 1186

Re: Early days of Broadcasting BBC

Martin, I noted that the presenter of this talk was also named Martin... just *might* that that person have been you?
The presenter is not me..

I have found on one of these websites a schematic of this 2LO xmtr:
2locircuitv2.gif
by pioneer
Fri Dec 27, 2013 4:14 pm
Forum: AM Radio
Topic: Harris MW-1 vs MW-1A
Replies: 18
Views: 3695

Re: Harris MW-1 vs MW-1A

That would be nice, thanks for that!

Martin
by pioneer
Fri Dec 27, 2013 4:05 pm
Forum: AM Radio
Topic: Harris MW-1 vs MW-1A
Replies: 18
Views: 3695

Re: Harris MW-1 vs MW-1A

If anyone have schematic of the MW-1 or similar transmitter I would be grateful for that.

It is for learning/study more of the modulation system 'progressive series modulation' and the modulation enhancer what used in the ME-1.
Particularly I am interested in this hard- clipper of the ME-1.

Martin
by pioneer
Fri Dec 27, 2013 8:40 am
Forum: AM Radio
Topic: Early days of Broadcasting BBC
Replies: 3
Views: 1186

Early days of Broadcasting BBC

Here I found a video, containing a lecture of early broadcasting in the 1920's. It is interesting to go back in those days and see what kind of transmitters they use. What also interesting is; who was the first in radio broadcasting what was a new phenomena. http://www.bbceng.info/videos.htm greetin...
by pioneer
Sun Nov 03, 2013 12:24 pm
Forum: AM Radio
Topic: Asymmetrical modulation
Replies: 68
Views: 16806

Re: Asymmetrical modulation

I discover some asymmetric modulation curves at the raw set up during tests; in my previous experiments the modulation curve was not symmetrical it go faster during negative modulation peaks than it was during the positive peaks. In the last few weeks i made some improvements to keep the modulation ...