CRT 7900 / KPO power mic ?

Anyone here using the combination  of the crt  ss7900 and KPO nm532 power mic ?

Why do you think you need a power mic? You don't, certainly not on SSB.

Northern Crusader wrote:

Why do you think you need a power mic? You don't, certainly not on SSB.

To be honest never been one for power mics since the early 80s where one of the fist things you bought after the radio and dv27 was a power mic ! But always feel the cheap mics supplied with these modern ssb radios are fairly poor and audio can be improved considerably by adding a KPO power mic or similar .

A couple of nice comparison videos on YouTube showing the difference in audio between standard and KPO and the audio on ssb is acceptable on the stock mic but very much sharper and punchier on the power mic providing the slider is kept fairly low.

Was just interested to hear of anyone else using this combination that’s all !

Hi gmham,

I also have the 7900 and found the mic to be a little quiet.

I decided to modify the position of the condenser inside and made a slightly larger speech hole in the front of the mic itself.
Since this, I have had good reports on the quality of the mic on both FM and SSB.

Regards

Graeme.

Okay thanks that’s great. What data file do you have for your own ss7900. Does it have the original uk40 fm freqs ?

Yes,

Original UK 40, easy to program though, as long as you have the cable.

Graeme.

Any chance of getting a copy of your file of you via email ? What you got on the other banks ?

I would need to re-check what is on each bank TBH.

I'm assuming you have the programming cable?

Drop me a PM, we should be able to sort something out.

Graeme.

Hi John,

I opened up the mic hole slightly larger, I believe it was about 5mm, or the internal size of the circular mount in front of the condenser mic when you have the case open

A point to note is I trimmed the opening by hand using  the drill bit, I believe an electric drill would shoot through the case with little or no control.

Hopefully the photos below will assist.

The photo below is before the Mod, this was taken from the internet as I have no pics from before I modified the mic. 




This pic shows the outside after the Mod, I used a trimmed silicone ear cup from an old earphone set to tidy up the hole.



This is the inside of the case after the hole has been drilled out, you can see the silicone ear piece inside the hole.



I used a small piece of lightweight foam to cover the hole inside, also good to protect the condenser surface.



To tidy up the drilled hole on the outside, I used a trimmed silicone ear cup from an old set of headphones.



Trimmed to size.



The original board from inside the mic was simply re-installed with the mic and the rubber cover over the condenser placed over the foam and screwed into place.


Hope that is of some help.

Regards

Graeme

That’s brilliant Graeme always better with photos ! 
Having tested the 7900 with a crt power mic the difference on ssb of peak power is amazing when compared to the little supplied hand mic. Hopefully with the mods should improve things on this one also !

Thanks again really do appreciate that. John