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-   -   Morphy Richards 27024 (http://www.drmrx.org/forum/showthread.php?t=1803)

David G4DMP 25-08-2007 08:33

Morphy Richards 27024
 
The audio from the internal speakers of the 27024 leaves much to be desired, the sound being very much lacking in top. Despite there being a crossover network using surface mount components on the main PCB, there appears to be almost no audio coming from the tweeter.

The quality can be improved by feeding the tweeter via a capacitor from the main speaker connection. I disconnected the tweeter from the PCB and connected the black wire to main speaker. I then connected the red wire from the tweeter via a 32F, 50v wkg non-polarised capacitor to the red connection of the main speaker.

I have also carried out this modification to the MR 27025 Internet Radio and both radios are now giving a more balanced output. You cannow actually hear sound coming from the tweeter!

73

David G4DMP

mitajohn 25-08-2007 17:32

Well done ! I believe that the cap's value is big for the tweeter. If it is 5 - 10 uF and the tweeter is 8 Ohm then you have a 6 dB point at ~4 - 2 kHz good enough for the tweeter. The 32 uF results at a 6 dB point ~600 Hz quite low for the tweeter.

David G4DMP 25-08-2007 18:11

Quote:

Originally Posted by mitajohn
Well done ! I believe that the cap's value is big for the tweeter. If it is 5 - 10 uF and the tweeter is 8 Ohm then you have a 6 dB point at ~4 - 2 kHz good enough for the tweeter. The 32 uF results at a 6 dB point ~600 Hz quite low for the tweeter.


Thank you, John. I have just changed the 32F to an 8F capacitor in the 27024 and in the 27025 radios and the audio quality is even better! I see that my local electronic store (Maplin) sell 10F 50V non-polarised electrolyics for only about 0.20 for anyone wishing to carry out the modification in the UK.

Regards

David

Digger 26-08-2007 14:59

Hi,

Never mind capacitors at all. Just connect the tweeter in parallel to the large speaker in the Morphy Richards. I stuffed some rock-wool loosely into the cabinet, this improved the sound even more.

I put a couple of response curves here:

http://www.drmrx.org/forum/showthread.php?t=1514&page=2

See #23, #25, #26 and #27. The posts are in German, the response curves are not :D

Digger 30-11-2008 20:32

Lousy AC adapter
 
Today, for the first time I enjoyed Beethoven' s 9th from DW on the Morphy Richards in the livingroom with the built-in telescopic antenna running on 230 VAC with the AC power supply which came with the receiver!

If you take a hammer and chisel, break the cover of the AC supply apart, solder 4 pcs of 10 nF capacitors across the rectifier diodes, then it works! All the horrible buzz and noise from the power adapter disappears!

Later in the evening I heard AIR Khampur, Langenberg and RAI on 846 kHz without problems. Why can't they think of this at the manufacturers???? A lousy AC adapter ruins the reception totally... :eek:

mvs sarma 01-12-2008 06:20

Quote:

Originally Posted by Digger
Today, for the first time I enjoyed Beethoven' s 9th from DW on the Morphy Richards in the livingroom with the built-in telescopic antenna running on 230 VAC with the AC power supply which came with the receiver!

If you take a hammer and chisel, break the cover of the AC supply apart, solder 4 pcs of 10 nF capacitors across the rectifier diodes, then it works! All the horrible buzz and noise from the power adapter disappears!

Later in the evening I heard AIR Khampur, Langenberg and RAI on 846 kHz without problems. Why can't they think of this at the manufacturers???? A lousy AC adapter ruins the reception totally... :eek:

You have rightly pointed. In fact we used capacitors across each diode,instead of searching where to keep, as it depended on characteristics of diodes.
These LOUSY ones and their manufacturers aim at cheapness, and nothing more.The Transformers become too hot as they would use low quantity and/or quality of core.

May I add another point that most adopters or wall warts what ever they are called, can well have regulators inside (linear though, as switching supplies are detrimental for radio Rx use.) and give a good stabilization and as on date adding a regulator for say 250 or 500mA load is not costly and it would help for good health of most equipment.

They can better stop making orthodox unregulated junk.

pb1 16-12-2008 20:57

I asked Morphy Richards if we could see a new software update to activate the EPG button for the DRM channels. This is the reply
Quote:

Our Design and Quality Assurance Department have confirmed that there are no plans to provide any future updates on this product, therefore we regret that we are unable to assist any further with your enquiry.

pksato 20-12-2014 00:44

Now I have this radio. But none DRM signal. :(
Ok, I can tune some DRM TX, but most have weak signal.
Using Dream and home made HF SDR, I pickup AIR, RNZI, and others, some time with audio.
I buy MR 27024 from
http://www.computeruniverse.net/prod...iorekorder.asp
Is for EU8.32 on 2014/12/19
But paid EU20.92 last month, took all most one month to delivered to Brazil. And need to pay custom taxes (R$85,06).

Firmware upgraded.
FM and AM ok.
DRM on testing.
No DAB on Brazil.
Need to replace power supply, I have only on wall socket with 220VAC, others are 127VAC.

Now, I trying to understand how to use it.

Some questions:
Is possible to change MW step from 9kHz to 10kHz?
Can upload (sd card) a use full station schedule?
Manually save station frequency?
Have a alternative firmware?
I found some hardware modifications, but none about firmware.

Unboxing

pksato 28-12-2014 19:43

Hi,
My radio was not holding date, all time when I apply power, its is reset time, and need to set clock.
After some search I found a datasheet with pinout of RS500 module, and other information, can have a optional super capacitor to maintain power to RTC. After some inspection, a found what capacitor is fault, not retain charge. I replace it with a 3V rechargeable battery, charged by 1.6V. Now I have a RTC working after power cut.
https://picasaweb.google.com/lh/photo/b8UK25LFcf_KL1OYHPfyW9MTjNZETYmyPJy0liipFm0?feat=d irectlink

G0SVN 29-12-2014 06:58

Hi Paulino,

Many thanks for the information about the backup power. Looks like you have got to know your new receiver well already!

I only know a little bit about the MR27024. So I can only answer your questions from my limited knowledge.

I don't think you can change the MW frequency steps to 10 kHz, or upload a schedule.
Yes you can manually save a frequency.
The only firmware I know of is version 1.12, I have a copy, if you want it.


Quote:

Originally Posted by pksato

Some questions:
Is possible to change MW step from 9kHz to 10kHz?
Can upload (sd card) a use full station schedule?
Manually save station frequency?
Have a alternative firmware?
I found some hardware modifications, but none about firmware.



ianf 05-12-2016 17:02

Just thought I would let the Forum know I will be selling the last batch of 27024 radios on Amazon in the new year,

PhilipOneL 06-12-2016 18:48

Ian, is there any difference between this batch and the earlier ones?
(Later serial numbers, previously owned, etc.?)


Philip

ianf 13-01-2017 08:00

Phillip
These are the last batch I've managed to obtain, they are 27024EE, the cartons indicate they are the late production run, one of the receivers I've looked at it serial number 60004537, I will upgrade firmware if required before shipping

PhilipOneL 14-01-2017 00:25

As peculiar as their operation is, I like my 27024s (I have two) and use them every day. I have replaced the main tuning button and some condensors on one of them but, other than that, they've held up well.


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