W2lHY EQ

[Sonar]

Does a hf transceiver need to operate at a certain bandwidth in order for these plug and play eq's to work.
Does using a plug and play eq like the W2IHY equate too ESSB?
I watched a video someone posted of Bob Heil talking about plug and play eq's/outboard audio gear and needing a transceiver that operates in the 2.9 wide bandwidth in order to appreciate the lows.
Has anyone used a plug and play device with a transceiver that operates below 2.9 kHz bandwidth and what were the results? 73

 

[Robb]

Does a hf transceiver need to operate at a certain bandwidth in order for these plug and play eq's to work.
Does using a plug and play eq like the W2IHY equate too ESSB?
I watched a video someone posted of Bob Heil talking about plug and play eq's/outboard audio gear and needing a transceiver that operates in the 2.9 wide bandwidth in order to appreciate the lows.
Has anyone used a plug and play device with a transceiver that operates below 2.9 kHz bandwidth and what were the results? 73

1. No
2. No

 

[unit_399]

The wider the audio bandwidth of the transciever you're using, the more effective a device like the W21HY EQ will be. If your transciever won't broadcast audio frequencies under, say, 300hz or over 2400hz, then trying to boost/cut freqs below 300 or over 2400 just won't happen.

If you have an audio signal generator, connect the generator output to the mic input, put your rig in the PA mode, and sweep the freq up from 0hz to 5000 hz. Note the freqs when (1)you begin getting audio output, and (2) when the audio begins to cut off. Subtract the lower freq from the higher. The result is the bandwidth capability of your radio's audio section. This is not necessarily the transmitted audio bandwidth, but it will give you a good idea as to your rig's capabilities.

The W21HY EQ allows cut/boost from 50 hz to 3200 hz. So, the closer a radio gets to a 3khz bandwidth, the more effective the EQ will be. Just don't expect miracles.

- 399

 

[2RT307]

I used to run a W2IHY 8 band EQ and EQ Plus on my Icom IC-718. The 718 is only about 2.8 wide on stock transmit. Look up "Bow" for some old posts and his modified 718 on this forum for wider tx results. You won't get ESSB per say... the low lows and the highs, but you will get a better sounding tx audio. I used to run the same W2IHY setup on a Galaxy DX2547 with very good results, and I was often asked if I was running an HF rig. Lots of people will poo-poo the W2IHY gear because it is expensive. (It is). The positive things I can say about W2IHY equipment is that it's extremely easy to setup and run (without having RF interference problems), and Julius' customer service is over the top, second to none. The guy even called me while he was on vacation to help me out with a problem I was having (level settings via the ACC jack on the IC-718). My 8 band and eq plus are about 8-9 years old now, and I have never had any problems with either unit.

I'm currently running the same W2IHY equipment on my FTdx-3000 with an inexpensive MXL R-144 ribbon mic with very good results. Even on the "modded" 4k wide mode, the Yaesu "only" hits about 3.6 with my setup as seen on a buddy's Flex.

If you're looking at getting into HF on the ham bands, then I'd certainly consider the W2IHY gear (or higher end equipment). You can usually find used 8 bands and eq plus units on QTH for reasonable prices when guys are moving on to rack gear.

Sorry for the ramble!

73,
Brett

 

[Sonar]

The wider the audio bandwidth of the transciever you're using, the more effective a device like the W21HY EQ will be. If your transciever won't broadcast audio frequencies under, say, 300hz or over 2400hz, then trying to boost/cut freqs below 300 or over 2400 just won;t happen.

If you have an audio signal generator, connect the generator output to the mic input, put your rig in the PA mode, and sweep the freq up from 0hz to 5000 hz. note the freqs when (1)you begin getting audio output, and (2) when the audio begins to cut off. Subtract the lower freq from the higher. The result is the audio bandwidth capability of your radio. This is not necessarily the transmitted audio bandwidth, but it will give you a good idea as to your rig's capabilities.

The W21HY EQ allows cut/boost from 50 hz to 3200 hz. So, the closer a radio gets to a 3khz bandwidth, the more effective the EQ will be. Just don't expect miracles.

- 399

I've been checking out hf's and the operating bandwidth of those in the $800-$1500 price range (used) and found that 2.9 kHz is about the max.
I've heard quite a few HF transceivers that operate with little more than a heil or studio type mic and manage to sound excellent.
A couple that stand out are the ft 950 and Kenwood ts 870.
If I'm correct both those transceivers have an adjustable bandwidth feature that maxes at 2.9khz.
Your description of how to get the bandwidth of a particular radio is excellent. Thanks. My interest in ESSB is strictly curiosity. The technical aspects of radio communications never really interested me until recently. Even if I don't put the information I get to use immediately I'm enjoying the lessons and I'm sure that in the future your lessons will come in handy. Thanks again. 73

 

[unit_399]

I should have mentioned that the same basic setup for finding audio bandwidth can also be used to generate an audio frequency response curve for your radio. Just connect an AC voltmeter across the speaker. I use an old Heathkit Audio VTVM because its 10 megohm input impedance doesn't load down the circuit. Simply record the voltmeter readings every 100hz or so, and plot them out on a graph of Freq vs Audio amplitude. The resulting curve will show you the freqs you need to boost or cut to get flat response. Hook the W21HY inline between the generator and the radio, and adjust the EQ to get a reasonably flat response curve (or a response curve that you like).

Most of the really good mics have a response curve in their spec sheet. With the baseline you generated above, you can readjust the Eq for almost any given mic.

If you're looking for natural-sounding audio, this is a good way to get it. 73s.

- 399