I know these are meant to produce harmonics and spurii, but what's everyone's thoughts on the audio quality? The stereo seperation seems OK - http://www.ebay.co.uk/itm/12V-BH1417F-F ... SwwNVTtXfR

I'm thinking of using one as a radio mic', bug type transmitter, or an "whole house" type transmitter.

The separation will be alright, they are not particularly noisy either. The guys in here hate them because of the "Oh Jesus" moment they give you when you hook them into a spectrum analyser. For what you want to use it for it is ideal, do not attach an amplifier though, planes will fall etc etc.

Some say that the BH1417 was responsible for the Wow! signal.

Or the woodpecker signal


Sent from my iPhone using Tapatalk

Off topic - this is the woodpecker, it's in the exclusion zone at Chernobyl and pure funny to look at as radio porn - note the guy in the pic for scale - those are 14MHz dipoles.

Ive got a 7watt chinese built exciter here whith BH14 chip in it. Yes audio quality is banging, sounds very good but the spread either side of the carrier is bad. Lets say I put it on 100mhz, it spreads noise approx 5mhz either side of carrier right down to 95mhz. When you short it so there is no stereo its clean but then obviously you get no audio.

Sorry about the late reply necks.

I ordered one for use as a bug transmitter, so will report back on how the modulation is.

Tempted to feed it into the shitty Turkish 15W amp that me and Teckniqs bought, but being under a flight path I scrapped the idea. Lol.

I have tested almost all in one chips.
For me the best are :

For rf purity : rda5820 but unknown sound quality as i never had one. There is a review showing spurious under 50db you can google it.

For sound quality: ebay item 331617734874 i have tested with turkish amp. Works very nice.
Nice open sound only with 10 euros.

Best bh ba type is crf t01 with only 1 watt output i have covered what i cover with 15 watts. It uses the bh1414 chip which is considered high end over 1415 etc. I purchased one for about 85 euros then sold it.

http://www.czhfm.com/index.php?main_pag ... ucts_id=51

Bh1415 , bh1417 etc are not good. I had several car transmitter the sound quality is not very good. I would tell is just acceptable.

Novaro wrote:I have tested almost all in one chips.
For me the best are :

For rf purity : rda5820 but unknown sound quality as i never had one. There is a review showing spurious under 50db you can google it.

For sound quality: ebay item 331617734874 i have tested with turkish amp. Works very nice.
Nice open sound only with 10 euros.

Best bh ba type is crf t01 with only 1 watt output i have covered what i cover with 15 watts. It uses the bh1414 chip which is considered high end over 1415 etc. I purchased one for about 85 euros then sold it.

http://www.czhfm.com/index.php?main_pag ... ucts_id=51

Bh1415 , bh1417 etc are not good. I had several car transmitter the sound quality is not very good. I would tell is just acceptable.

I ended up buying the DSP Transmitter as per the item number.

The RF out is very low (probably 20mW), but the audio quality with the onboard electret is really good. I've yet to test audio into the 3.5mm socket, but will get around to it later.

Pcb wizard on eBay is selling a stereo encoder with bh1417, he has a new 2017 version which looks exactly the same as the old one, is this ok to use on my 150watt rig? I've never tested this chip and currently don't have access to an analyser

I have sold hundreds of Chinese transmitters in the past, from the time there was only HLLY as a Chinese vendor. Then other Chinese sellers came and they started copying the HLLY transmitters and probably each other, sometimes skipping essential parts like LPF filters.

I started selling the versions without models numbers (with those separate display segments).
Then came models like: TX-01S, TX-99A, ST-15B, ST-7C, CZH-5C/7C/15, CZH-15, CZH-T251, SDA-01, SDA-15B.

The best transmitter was the CZH-T251 model. About 25W with very good audio quality and nice stereo signal.
This one probably uses the Rohm BH1414 chip. It was a bit expensive tho. People wanted the cheap models and started adding amps to it.

The audio from transmitters that use the BH1415/1417 is not very good and the stereo does sound weird.
I can describe it as: audio with very bad stereo separation but corrected with some stereo widener plugin.

Yep the pilot level is through the roof on the 1415/1417s. Probably why the stereo sounds weird.


Sent from my iPhone using Tapatalk

It's this stereo encoder here
http://m.ebay.co.uk/itm/STEREO-ENCODER- ... Ciid%253A2

I'll stay clear then. Why do these people build and sell shit? They could build a proper encoder for not much more cost.

Banus_radio wrote: ↑Fri Feb 17, 2017 2:07 am Pcb wizard on eBay is selling a stereo encoder with bh1417, he has a new 2017 version which looks exactly the same as the old one, is this ok to use on my 150watt rig?

No.