HLA 150 Audio Grunge
FlexRadio Systems Forums
Home       Members    Calendar    Who's On
Welcome Guest ( Login | Register )
        


HLA 150 Audio Grunge Expand / Collapse
Author
Message
Posted Saturday, July 2, 2011 11:02 AM
Forum Newbie

Forum NewbieForum NewbieForum NewbieForum NewbieForum NewbieForum NewbieForum NewbieForum Newbie

Group: Forum Members
Last Login: Thursday, May 3, 2012 9:43 AM
Posts: 8, Visits: 15
I am a new owner of a Flex 1500.  I get perfect audio reports barefoot and also with a Heath SB200 linear  with 5 watts in and 50 watts out.  The audio when monitored on a Yaesu FT-950 is smooth as a baby's behind.

I purchased the HLA-150 from H&Y, it makes great power output, but the SSB audio is not a smooth as the tube linear.  I have used the HLA-150 barefoot with the Flex 1500 and also driving the Heath SB-200.  I have had numerious on air reports, the audio is near perfect, but has a little choppyness at times when running the HLA-150 barefoot or the HLA-150 driving the Heath. 

I don't think the HLA-150 is biased just right for SSB.  If I attempt to lower the drive on the Flex to allow lower output, say 80 watts drive into the SB-200 the audio become more choppy and clips.  It is like I have to run the Flex 1500 at full drive for best result of SSB audio.

I called H&Y and Bob said factory warranty would mean shipping it back to Italy, he suggested you don't want to do that.  The only return policy is within 2 weeks of purchase.  He suggested I call a man in Tennesse.  All I get is a phone answering service that the call has been forwared to a voice mail after two calls.

I tried running the HLA-150 both Manual and Auto.  No difference.  Bob at H&Y suuggested I run the SSB switch on, I commented the manual says that only holds the PTT if one is running Auto.  He said no you want to run SSB when running SSB.  So I un-hooked the PTT line, switched the amp to Auto, 3DB swich on and SSB delay on.

Are there some experts with linear building that could tell me if this amp is biased too close to 0 for SSB??

Personal comment, the support from Flex is just great, that from H&Y is on the opposite end of the specturm!  I am waiting for email replies from H&Y.

73

Dave

K0RWM

Post #4578
Posted Saturday, July 2, 2011 9:15 PM
Forum Newbie

Forum NewbieForum NewbieForum NewbieForum NewbieForum NewbieForum NewbieForum NewbieForum Newbie

Group: Forum Members
Last Login: Thursday, May 3, 2012 9:43 AM
Posts: 8, Visits: 15
I received a call from the genteman in Tennessee.  His comments were very good, so appears H&Y Support is going to be excellent.

I will keep you informed.

73

Dave

K0RWM

Post #4581
Posted Thursday, July 7, 2011 6:03 PM
Supreme Being

Supreme BeingSupreme BeingSupreme BeingSupreme BeingSupreme BeingSupreme BeingSupreme BeingSupreme Being

Group: Forum Members
Last Login: Friday, May 24, 2013 6:00 PM
Posts: 140, Visits: 156
Dave,

I use the HLA-150 without any of the symptoms that you mention are plaguing you... SSB delay on and 'Auto'.

However, just some observations: a tube amplifier will always be more linear than a 13.8VDC solid state amp, unless it is designed to run at say 50VDC. This is due to the IMD value (IMD3) of about -24db for a SS amp and -35db for a tube amp. The HLA-150 will typically be running in Class AB - see http://www.smeter.net/amplifiers/classes-of-operation.php

AB4OJ wrote an interesting article on Linear Amplifiers some time ago - you can either Google or QRZ.Com for his web page (if it is still up?) if you want to really get into it?

5 Watts from your Flex1500 should drive it to about 100Watts which is fine if you don't mess around with the FLEX mic and compander settings - switch them all to off and then set mic to about level #4 and your audio should be 'sweet'!

I would suggest your problem is the 1500 settings rather than the linearity of the amp, which is certainly not being overdriven, while the 1500 will not give you any ALC controlled output level, you might want to try and reduce drive to say 85-90% as the saying goes: 'garbage in garbage out and the Flex PA is not being overdriven at that level either..

The 1500 is somewhat notorious for 'spikes' on RX/TX transitions!

With a maximum drive level of 10W on the HLA-150, and the 5W output of the Flex1500 - you are well below any final-damaging transient levels or voltages, however I never exceed 85% drive with an ALC-unprotected amplifier!

Also are you using a vertical Ant by any chance? If so you could getting RF feedback through your mic - btw what mic are you using??? this could be important! (I use the Yaesu MH-31)

A fascinating hobby isn't it?

73

Terry ve3ega

Post #4601
Posted Friday, July 8, 2011 10:51 AM
Forum Newbie

Forum NewbieForum NewbieForum NewbieForum NewbieForum NewbieForum NewbieForum NewbieForum Newbie

Group: Forum Members
Last Login: Thursday, May 3, 2012 9:43 AM
Posts: 8, Visits: 15
Great information and advice.

The gentleman from Tennessee who builds amps and knows the HLA-150 very well, modifies these only for hams on SSB. He checks out the address first to make sure it is not for a CBer.

For an instant at the beginning of the wave the amp begins in Class C then goes to AB1. The Flex has a very clean, fast signal. What he has done is modify the bias removing it from the input stage to the bias being developed across each of the two output transistors. It will require at each location, a diode, some non inductive resistors and a 47 pF high voltage capacitor. The concept here is to make it run as close to AB1 at all times.

The amp design by most CB companies is to purposely use Class C for more efficiency and less cooling requirements.

Per Dudley's excellent advice on RF suppression, I grounded the PC with its own wire to station ground, put ferrite cores on the USB cable next to the computer, the mouse, keyboard, and have a ferrite core on the mic input. I even have the excellent "white paper" on setting the audio, downloaded from the Flex Wiki site.

The Heath SB200 linear when fed the 5 watts will produce a super clean 50 watts out, that sort of eliminates the Flex adjustments. I do understand what you say about tube vs solid state.

My friend in Fairbury has a 1500 with the Tokyo Hy-Power 45 watt amp and it sounds perfect. However, that combination has its issues. I visited with the service rep at their booth in Dayton. They have lost amps on the Flex 1500s because the PTT delay needs to be set to 100 mS delay allowing the amp time to key up before RF is applied. The amp was really designed for the Yaesu. So that must come back to the fact what the man from Tennessee told me, the Flex has an extremely fast, clean wave. It might be good for those using the Tokyo amp to check with the company to see if I understood the need to use the 100 mS delay on the Flex PTT when using their amp.

My issue is, I only hear roughness at times on the very beginning of a word. Rest of the word it is very good.

The SSB Delay is only a capacitor that holds the PTT on during AUTO operation between words.

After 52 years in ham radio, 35 years in broadcast engineering and now 15 years in industrial controls, it is a very fun, interesting hobby. I liked broadcasting a lot, but working for a utility programming and designing PLC programs is like retirement. Who ever heard of a 40 hour week in radio?


Dave
K0RWM

Post #4604
Posted Saturday, October 15, 2011 1:45 PM
Forum Newbie

Forum NewbieForum NewbieForum NewbieForum NewbieForum NewbieForum NewbieForum NewbieForum Newbie

Group: Forum Members
Last Login: Thursday, May 3, 2012 9:43 AM
Posts: 8, Visits: 15
Fast forward to October 15, 2015 and my second HLA150 plus.  There must have been something wrong with the first one I got and had reported on.  The replacement is very good.  I am getting good audio reports and it seems to works very well. I had some questions about keying and received, EXCELLENT, RAPID, ACCURATE answers from the Rmilta in Italy.  I am impressed with their support and design.

Can not fault my HLA150Plus.  I run the Flex 1500 at about 70% drive, the -3DB IN switch ON, and have a steady 100 watts out.  When driving a Heath SB-200 I reduce the Flex drive giving me 80 watts out from the HLA-150.    I suppose one could drive the Flex to 100% and turn OFF the -3DB in and do 150 watts, a few extra watts out doesn't make that much difference. 

From what I have read on several fourms, running the amp at 100 watts out provides a very clean signal.  I am more interested in that idea.

So for the record, I want to remove the word Grunge from anybody's mind when it comes to how the HLA-150 works.  Where else can you buy an amp that will take 5 watts in and give you a nice clean 100 out?  Its either that, or jump to the Flex3000.  One needs at least 100 watts to make another amp work.

73

Dave

Post #5021
Posted Thursday, October 27, 2011 3:47 PM
Forum Guru

Forum GuruForum GuruForum GuruForum GuruForum GuruForum GuruForum GuruForum Guru

Group: Forum Members
Last Login: Sunday, June 9, 2013 10:21 PM
Posts: 55, Visits: 106
Dave,
A dumb question since I am thinking of possibly getting a HLA-150 Plus. It is ONLY RF detect keying or does it have a connector to key it with the Flex 1500?

---Gary WB8ROL

K0RWM (10/15/2011)
Fast forward to October 15, 2015 and my second HLA150 plus. There must have been something wrong with the first one I got and had reported on. The replacement is very good. I am getting good audio reports and it seems to works very well.I had some questions about keying andreceived, EXCELLENT, RAPID,ACCURATE answers from theRmilta in Italy. I am impressed with their support and design.

Can not fault my HLA150Plus. I run the Flex 1500 at about 70% drive, the -3DB INswitch ON, and have a steady 100 watts out. When drivinga Heath SB-200 I reduce the Flex drive giving me 80 watts out from the HLA-150. I suppose one could drive the Flex to 100% and turn OFF the -3DB in and do 150 watts, a few extra watts out doesn't make that much difference.

From what I have read on several fourms, running the amp at 100 watts out provides a very clean signal. I am more interested in that idea.

So for the record, I want to remove the word Grunge from anybody's mind when it comes to how the HLA-150 works. Where else can you buy an amp that will take 5 watts in and give you a nice clean 100 out? Its either that, or jump to the Flex3000. One needs at least 100 watts to make another amp work.

73

Dave



--Gary WB8ROL
Post #5057
Posted Monday, January 16, 2012 2:32 PM
Forum Newbie

Forum NewbieForum NewbieForum NewbieForum NewbieForum NewbieForum NewbieForum NewbieForum Newbie

Group: Forum Members
Last Login: Thursday, May 3, 2012 9:43 AM
Posts: 8, Visits: 15
Sorry I over looked the question on keying. There is a choice of both AUTO or PTT. Also one can select the band ahead of time, or AUTO will sense correct bandpass.

I am impressed with the construction. Also this is an amp that covers 160 meters.

I am now at the point where I am planning on upgrading to the Flex 3000 or 5000 RX2.

I really like Power SDR very much. Since I am never interested in QRP, I am planning on selling my HLA-150 Plus. This is the second unit. I think the first one I had may have had some issues, but that happens with every product line from time to time.

73

Dave
K0RWM
Post #5330
Posted Friday, October 25, 2013 4:07 PM
Forum Newbie

Forum NewbieForum NewbieForum NewbieForum NewbieForum NewbieForum NewbieForum NewbieForum Newbie

Group: Forum Members
Last Login: Friday, October 25, 2013 3:59 PM
Posts: 4, Visits: 3
Gday everyone,
Ive found the same problems with the amplifier, here is an email I just sent to a friend.


Hi Brian,
Regarding the issues that we briefly discussed (flex1500 running into some amplifiers)

The amplifier that I was having troubles with is a RM Italy HLA150, I had another look into it yesterday.

It seems that this amplifier (and possibly your one?) has a RF input "threshold", the bias to the power devices only turns on when the threshold is overcome.
I am guessing this reduces the chance of oscillation in the amplifier? (like a noise gate).
For some reason with the Flex1500, this "threshold" level is much too high - giving a digital affect to the amplifier output (the bias wasn't turning on until speech levels get quite high and then turning off too soon)

I didnt seem to have this issue with other radios- only the flex, so im not 100% sure where the problem is originating

So anyway to "fix" the problem, I disconnected the RF sense circuit- Bias now comes on as soon as the amplifier is keyed. (as in most amplifiers)

Look forward to catching you on the air,

Cheers and 73, Graham VK3XDK
http://www.vk3xdk.net46.net/


With my HLA150, I just disconnected Diode10. I am not sure what other affects this will have yet (at your own risk if you choose to do the same)
It would be nice to lower the "threshold" rather than disconnecting it, but havnt worked it out yet.
I am now getting very nice audio. (running in class AB at all times)

The other thing I have found with the HLA150 is that the "hard wired PTT circuit" doenst work properly and gets locked on TX sometimes.
I have chased the fault all the way to the processor, it seems that there is nothing that can easily be done to fix it. (may be a software bug)

cheers, Graham VK3XDK
Post #6902
« Prev Topic | Next Topic »

Reading This Topic Expand / Collapse
Active Users: 0 (0 guests, 0 members, 0 anonymous members)
No members currently viewing this topic.

Permissions Expand / Collapse

All times are GMT -5:00, Time now is 8:03pm

Powered By InstantForum.NET v4.1.4 © 2018
Execution: 0.047. 9 queries. Compression Disabled.