Re: My Murania AM Radio isn't working

Philip Karras <ke3fl@...>

Hi Steve,

The instructions said to use only 1.5" for the loop, also my loop location seems to be more under the rod and not next to it. I think I'll increase the length of wire used for the loop. At present there's no way any of the loop can be above the rod in my set up. I'll take a photo of my radio as it is right now and then make changes.

I'd like to know of any mods as well.

73 de KE3FL,

On Thursday, February 11, 2021, 6:58:17 PM EST, Steve Beckman <n3sb@...> wrote:

Hi Phil;

The Murania is capable of much better performance than that. Have you tried adjusting the position of the regeneration link? Too much regeneration is as bad as too little. On mine the link ended up facing mostly towards the top of the radio, as opposed to being in parallel with the turns of the coil on the ferrite rod. 

Since building it, I made a simple wiring modification that turns the volume control into a regeneration control. This mod permits setting the optimum regeneration for the frequency and the strength of the station of interest.

In the evening, the band is full of signals. WBZ Boston is booming in right now, and my QTH is not that far away from yours.

73; Steve, N3SB 

Sent from my Sprint Samsung Galaxy Note8.

-------- Original message --------
From: "Philip Karras via" <ke3fl@...>
Date: 2/11/21 6:27 PM (GMT-05:00)
Subject: Re: [4SQRP] My Murania AM Radio isn't working

Second test: I tuned the radio again and found an extremely weak station around 11 (1100kHz) holding the radio full volume close to my ear I was able to understand the transmission. I then got another AM radio and tuned it until it interfered with the Murania radio and it was tuned to ~1100 kHz as well.

So it is working just not at all well.

73 de KE3FL,

On Thursday, February 11, 2021, 6:13:14 PM EST, Philip Karras via <ke3fl@...> wrote:

OK, the radio is all together but does not work at all well.

I live 20 miles from Baltimore, Washington DC and 15 miles from Frederick Maryland with numerous AM stations still active and yet I hear nothing.

The LED does get dimmer near the higher end of the band and at full volume I can hear squeals but no stations are heard.

There is static and if I place it near a switching power supply, wall wart, I can hear the characteristic high pitched AM noise. So it does well hearing digital AM noise and probably lightning as well but as a radio it is not working.

Any ideas as to what I can TRY? I think it is obvious that the audio section works also the tuner works at least to some degree but the AM decoding doesn't seem to be working or my tuner is way off the mark.

I have a frequency generator which goes up to 1 MHz, but I could use a square wave & get all the odd harmonics, I did that once with an AM transmitter I made, tubes, when I chopped off part of the sine wave (over driven) and on our big receiver I was transmitting from the fundamental all the way up as far as the receiver would go. So here's what I've tried with the generator so far:

With my scope, an Alinco DJ-X10 wide band receiver and the Muranai:
Scope kHz
601.8 X-10 = quiet at 601.8 kHz Mur ~not found
702.2 X-10 = quiet at 702.2 kHz * Mur between 5 - 6
900.2 X-10 = quiet at 900.2 kHz * Mur ~ 7
1044.0 X10 = quiet at 1044. kHz * Mur between 8 - 9

The X-10 also has a band scope and it showed a bad of frequencies being received centered around the frequency tuned in. All was quiet since the signal was not being modulated.

Tnx es 73 de KE3FL,

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