Anybody know where you can get this heatsink. Seems as though Mouser no longer stocks them. Thanks in advance

Gary

Roland,
Scan back to message number 13 it notes an earlier problem with the FAR Circuits board. If not, then perhaps you can isolate the defective relay by removing the solder from the input pin with some soder-wick.

Jim

I have a continuity in the filterboard between the input strip and ground. Can't find any solder bridges. Any ideas? I hate to think of trying to pull the relays. Thanks es 73

I would caution builders to make sure that the chassis surface under the soft thermopads beneath the power transistors is very clean and smooth. I had a nagging "loss of insulation" problem that was resolved when I discovered that a fine, hardly visible, aluminum burr on the chassis had actually cut through the pad to short the collector tab.

Also (by the way) I've noticed that the latest Mouser catalog (Cat. 621) refers to an incorrect illustration and pinout for the NEC relay type MR-82-12USR (K-1 on the main board). The part number for ordering is correct (551-MR82-12USR, and the illustrations themselves are actually labeled correctly.

I am indeed interested in a group purchase. How about some teflon wire also. I'd like the heatsink too.

My address is good in the callbook. rcnixon (at) mindspring (dot) com

Russ

Is anyone interested in a group purchase of 2SC2312C to beat RF Parts minimum purchase? I toasted mine when connecting the filter board. Thanks /John

Rob, I had a similar experience. I haven't had time to troubleshoot but am thinking I may be victim of the problem identified in message #13 re the problem with the Far filter board. Good Luck! /John

I completed the amp board and adjustments with approx 30 watts at 14 mhz. When I added in the filter board and tested it, it appeared to work too... relays clicking, etc. All of a sudden, no power output from the amp.... a "small jump" in the watt meter (less than a watt) and nothing. I can hear the PTT relay kicking in. There are no apparent fried/burned parts.
  Amy suggestions on how to trouble-shoot?

rob
n3hu

I don't have a copy in front of me but as I recall D8 is not on the PC board. It is hardwired directly to the power connector on the chassis. D6 can be mounted directly to ground without any special hardware.

Jim

I am currently traveling out of the office and will not return until Tuesday morning, March 2.

Am I blind or is D8 not shown on the parts placement diagram. It looks like it can go somewhere near and parallel to C19? The parts list only calls for 2 T-220 mounting kits. Does D6 not need to be mounted similarly to Q3 and Q4? Thanks /John

Anyway, onward! - Mort Saul

Nothing magical about the heatsink – it stays cool in SSB service. I suspect the case will work fine. Power supply should be 5 Amps or so.

Jim

Does anyone know what the minimum power supply is for this amp ie. how much current it draws with the key down?

Also Mouser apparently quit stocking the heat sink, any experience operating the amp using only the case as a heat sink?

73 John

Does anyone know if the filter board and relays will handle 140 watts? I'm thinking of using this board for another amp project I am working on.

Jonathan
WA3WDK

Al,
It will do a fine job on CW. At 4 watts you output will be a little lower than if driven with 5 watts...but who will know the difference. Hi Hi Have fun. It a nice amp.
Pete AB2KG

To AB2KG or any others using this amp:

You're welcome Pete. Looks like the forum isn't monitored much anymore. Have you used this linear on CW? I really want to use it on CW at this time. I have a Smallwonderslab DSW-II-20 coming which is a 4W CW xcvr. I then want to get a QRP PSK-31 xcvr and then use the amp for that.

Al - K8AXW

Al,
Thanks for the information. I will note it for furture projects. I have already finished building my 30 watt amp last August and have been using it a lot since then. It realy works great.
Pete
AB2KG

To AB2KG and others looking for Teflon coated wire in various sizes-
RF Parts sells this wire in 10, 50, 100 and 500ft lengths. Ordering it from them will help meet the ridiculous $25.00 minimum order requirement.

Hook up wire should be stranded for it's flexibility. Radio Shack sells it. #22 is good for signal levels or low power... use heavier wire for high current circuits.

AL - K8AXW

I picked up a used Yaesu FL-110 amp, so I do not need to finish this amp project...

I have an ALMOST COMPLETE "kit of parts".. all that I lack are the toroid cores.

I forget how much I have in this project so far, but if someone were to make a FAIR AND RESONABLE offer, they might have a head start on parts collection.

bob K8YS k8ys@arrl.net

I am presently obtaining parts/boards, etc. for this "winter project."

The unit described is for SSB but I would like to know if any mods or bias changes need to be made to use it on CW?

73

AL

    How important are the ferrite beads (not mentioned in the text or parts list) to the functionality of the amplifier?

The T-50-2 cores for 160M and 80M are wound with the #24, 30 turns and 22 turns respectively. The remaining T-50-2's and the T-50-6's are wound with #22. You can find this documented in the handbook project from this filter was taken.
Pete
AB2KG

Why did AMIDON send me a equal lengths of #22 and #24 wire?
The instructions say #22, but there is not enough of it to finish.

Jim,
I have replaced both transistors and added a thin coating of thermal grease between the large heatsink and the top of the chassis. The amp tuned up fine. Last night I put in the filter board and measured about 38 watts out on 40, 30, 20 and 15 meters (the four bands my K1 uses) into a 50 ohm dummy load. I'm looking forward to trying it on the air this weekend. Thanks again for a great project!
David

Jim,
Fortunately I can still hear the relay switch in when I ground the PTT. The plastic washer/spacer in the tab of Q3 is the only part that shows visible heat damage. The amp is drawing very little current, whether idle or in transmit mode. I have ordered replacement transistors for Q3 and Q4 (along with a few extras) from RF Parts. Since the vendor has a minimum purchase requirement I also picked up some heatsink grease and a "Feedback Mod Kit for solid state amps", among other items. After I have the amp properly tuned and tested for normal operation, I thought I might try the feedback modification. Do you recommend putting a film of grease between the heatsink and the chassis, or is that unnecessary?
I'll let you know how it works out.
Thanks again for your advice.
David

David,
The amplifier has no VSWR protection, as you discovered. The ~~100 watts is likely your meter summing the forward and reflected power. In any case, how much current are you drawing at idle? If it's high at least one of the transistors is likely damaged (shorted), if not, it's still possible that they are bad. You can try an ohm meter check or simply replace them. Check for damaged parts - overheated resistors, etc. Also, check that the relay is functioning, perhaps you've 'welded' the contacts.

Good luck!

Jim

Jim,
This evening I decided to re-tune the amp as a practice run for a demonstration at my ham radio club. When I keyed down, the needle on the meter shot past 40 watts and looked like it was near 100 W. I quickly released the key waited a minute, then keyed again. This time the needle was far below 40 W and I noticed very high SWR. I took my dummy load apart and found that the ground wire from the resistors to the BNC connector had become detached. I repaired the dummy load and now have practically no SWR, but the power output of the amp is about 1 to 1.5 W.
The plastic mounting kit washer/spacer that goes into the center of the tab on Q3 looks like it was partially melted, though the multi-meter tells me that the tab is still insulated from the mounting screw (i.e., not grounded by the screw to the chassis). I suspect however, that I may have fried the transistor. Does this seem like a probable diagnosis? Is there some other place that I should look for the problem (i.e, other parts that are likely to need replacing)? I notice that the plastic washer/spacer in the tab of Q4 looks undamaged.
Thanks for any suggestions.
David

David,

Looks as though you are making progress! I agree, the thermo pads are a lot easier to work with than the thermal grease. Ok on the V+ wire ... that will help! Welcome to the club - we've all done something like that.
Ok on the power ... it will drop off with the filter card in place once the harmonic content is under control. The pot doesn't require to much adjustment, seems about right.

Jim

Jim,
    Thanks for your reply. I have replaced the mica insulators with the thermal pads (I didn't want to mess with grease).
    After reviewing the schematic, it suddenly occurred to me that I had forgotten to run a wire from the power switch to the +V pad on the circuit board (of course, I feel very foolish over this). After doing so, the indicator LED's functioned as expected and I proceeded to tune-up.
I only had to turn the potentiometer about 35 to 40 degrees from ground position to achieve a 15% power increase. Further adjustment did not yield any increase in power. My meter (not the most accurate) read about 40 watts on 14 MHz with 2 W drive at 14.7 V dc. The QST article gives an approximate 35 W output, so I guess I'm in the ballpark. Does the potentiometer adjustment sound about right? I was surprised that it took relatively little adjustment.
    The next step is taking readings with the filter board in place. Now that I can see the light at the end of the tunnel, I'm starting to feel some sense of accomplishment and am excited about getting this project on the air. I'll be using it with an Elecraft K1.
    Thanks again for all of your help.
David

David,

When mounting the TO-220 packaged transistors, do the thermal insulator pads go between the transistors and the mica insulators, or between the mica insulators and the chassis?

WITH THE THERMAL PADS YOU DON'T NEED THE MICA INSULATORS. IF YOU HAVE ONLY THE MICA BE SURE TO USE SOME THERMAL GREASE.

I realized, after I had mounted the transistors, that I had left these off. It's going to be difficult to get them in place now.

When I turn on the power switch, the Transmit LED (green) lights up along with the Power LED (red). This happens even though I have not externally grounded the PTT circuit and have no RF input connected. I've used my multi-meter to check the wiring but can't find anywhere that it is grounding the PTT. Any suggestions?

THE 'LOW' SIDE OF THE RELAY MUST BE PULLED TO GROUND SOMEHOW. ON A LOW RESISTANCE RANGE MEASURE FROM THE C7 SIDE OF THE RELAY TO GROUND - WHAT DO YOU SEE? SWITCH THE METER TO A VOLTAGE RANGE, TURN ON 12 VOLTS TO THE AMP AND MAKE THE SAME CHECK - YOU SHOULD SEE 12 VOLTS. IF IT'S NOT 12V, LOOK FOR A SHORTED COMPONENT - C7,10,20 OR Q1. IF YOU SEE 1.5 - 2 VOLTS, CHECK TO SEE OF D1 IS BACKWARDS.

JIM



Thanks,
David

When mounting the TO-220 packaged transistors, do the thermal insulator pads go between the transistors and the mica insulators, or between the mica insulators and the chassis? I realized, after I had mounted the transistors, that I had left these off. It's going to be difficult to get them in place now.

When I turn on the power switch, the Transmit LED (green) lights up along with the Power LED (red). This happens even though I have not externally grounded the PTT circuit and have no RF input connected. I've used my multi-meter to check the wiring but can't find anywhere that it is grounding the PTT. Any suggestions?

Thanks,
David

The FARA TekTalk pages have been updated with a copy of the QST article (reprinted with permission), along with an updated parts list and PDF files for the drilling templates.

Jim

Can anyone tell me if an IFR 1600S communications service monitor will work for testing amateur radios in the UHF anf VHF range. Does it have a spectrum analyzer, can it read deviation, can it read sinad, eetc. Is it as good as an IFR 1200S?
Sid KN4EW

Jim,
I received the PDF files -- thanks! They printed to proper scale when I used my work computer and printer. I then tried the ARRL PDF files from work, and they also printed to scale, so obviously I have some software/printer configuration issue at home.
Also, thanks very much for the clarifications on resistor values, grounding PTT, and testing. This is a great project and I'm really enjoying the learning experience.
Thanks again for your help!
David

David,
I’ll forward the PDFs to you soon.
A few answers to your questions …
1. Yes, the PTT line can be grounded manually even with the RF switch circuitry in place.
2. With 2 watts drive omit R2 & R3 (schematic) –DON’T OVERDRIVE THE AMP WITH 5 WATTS and no attenuator.
3. The tune up drive actually refers to what the input to the input of T1 ‘sees’. Maximum drive to the input of the RF stage (at T1) should be limited to 2.5 watts. The tune up instructions actually refer to this point. R1, 2,&R3 form a –3dB pad, that is half of the input power is dissipated in this network resulting in about 2 watts drive with the maximum 5 watts output from the FT-817. SORRY FOR THE CONFUSION.

Jim

Thanks, Jim. My email is dswain100@netscape.net.

I have a few more questions that someone may be able to answer:
1) I have assembled the parts for the optional RF activated PTT switching circuitry on the PC board. Can I still test and use the amp by simply grounding the PTT line?
2) On the RF amplifier schematic, the values for the amp input attenuator at 2 watts for R2 and R3 are dashes. Does this mean that R2 and R3 are not used, or does it mean that the value of 300 ohms from the row above is to be repeated.
3) In the QST article, page 39, is it correct to assume that the tune-up and testing power levels specified are for an amp built with an input attenuator for 2 watts.
I know that the answer to some of these questions must seem obvious to the more experienced builders, but I'm fairly new at this and I'd hate to damage any amp components by making a bad assumption.
Thanks in advance for your help,
David

I haven't downloaded the ARRL template file. I have the templates as a PDF file, send me your email address and I’ll forward them to you.

Jim

I printed out the chassis and heatsink drilling templates from the binaries at the ARRL website. However, when I went to lay the template over the heatsink, I noticed that the markings did not line up with the notches in the side of the heatsink. I got out my ruler and discovered that the dimensions on the printout do not match the indicated measurements. The templates print about 5 to 10 percent to smaller. I tried downloading again and reprinting, but got the same results. My software tells me that I'm printing at 100 percent of the original document size, so I'm wondering if the templates on the ARRL website are slightly reduced from the original size.
Has anybody else had this problem? Could anybody share templates that print at full size?

Edited by author 08-26-2003 10:31 AM
LET'S SEE IF I CAN OFFER A FEW SUGGESTIONS...
I need help.
1)I have completed assembly of both boards, and have mounted the HF amp board in the enclosure and connected the various cchassis components.I checked Q3&Q4 to make sure they were isolated.
DOUBLE CHECK THE COLLECTORS TO SEE THEY ARE ISOLATED

2)I do not have access to a IFR - 1600S service monitor. I do have a radio shack SWR/Watt meter. I hooked up my Yasue FT817 and ran it on battery. When I transmitted a carrier with packet I read 1,2-1/2,and 5 watt on the meter when I was transmitting on 1 watt, 2-1/2, and 5.
OK
3)I hooked up the amplifier as instructed in the instructions, applied 12.7 volt to the amp with a battery since I don't have a regulated 12 v source. Before I turned on the amp I checked the output through the amp in the off position with one watt and that is what showed on the watt meter.
OK ... TRY TO FIND A POWER SUPPLY WITH METERS, BEING ABLE TO SEE THE VOLTAGE AND CURRENT BEING DRAWN IS HELPFUL. A BATTERY IS OK, BUT IT NEEDS TO SUPPLY 7 AMPS OR SO CURRENT
4)I jumped out the PTT to ground and teh relay pulled in and the FT-817 stopped receiving indicating the relay did pull in. When I transmitted with 1 watt this time I got a blip on the watt meter and then NOTHING at all out of the amp. Note: I disconnected the PTT and tried it again and the green transmit light came on, the relay pulled in and I got the same blip on the watt meter and then nothing.
OK ... THE T/R SWITCH SEEMS TO BE WORKING, DOES THE RELAY REMAIN ACTIVATED WHILE YOU HAVE DRIVE APPLIED OR DOES IT DROP OUT? MAKE THIS CHECK WITHOUT THE FILTER CARD IN PLACE, USE A DUMMY LOAD. WHAT IS THE BATTERY VOLTAGE UNDER LOAD? HOW MUCH CURRENT IS BEING DRAWN FROM THE BATTERY?
5) I did check the voltage regulator U1 with the unit on. In the grounded position it put out about 12.6 volt and when I turned pot on R15 the voltage dropped to around 7 volts. I did put the jumper between filter in and out.
JUMPER THE PTT LINE TO GROUND, WHAT VOLTAGE DO YOU MEASURE
AT THE CENTER TAP OF T1 (Q3&4 BASE)??
6)Any suggestions. Could it be Q3 or Q4? The soldering looks OK but maybe I messed up some place.I looked very carefully to see if something was shorted but I couldn't see anything
Any help would be greatly appreciated.
DID YOU INSTALL THE GROUND STRAP IN THE EMITTERS OF Q3&4? CHECK TO SEE THE EMITTERS ARE GROUNDED.
Pete
AB2KG
IF YOUR ABLE TO MEASURE CURRENT THAT SHOULD PROVIDE AN INDICATION IF THE AMPLIFIER IS BEING DRIVEN. IF THERE'S NO DRIVE WORK FROM THE INPUT TO THE OUTPUT. CHECK T1.

GOOD LUCK.
JIM

I need help.
1)I have completed assembly of both boards, and have mounted the HF amp board in the enclosure and connected the various cchassis components.I checked Q3&Q4 to make sure they were isolated.
2)I do not have access to a IFR - 1600S service monitor. I do have a radio shack SWR/Watt meter. I hooked up my Yasue FT817 and ran it on battery. When I transmitted a carrier with packet I read 1,2-1/2,and 5 watt on the meter when I was transmitting on 1 watt, 2-1/2, and 5.
3)I hooked up the amplifier as instructed in the instructions, applied 12.7 volt to the amp with a battery since I don't have a regulated 12 v source. Before I turned on the amp I checked the output through the amp in the off position with one watt and that is what showed on the watt meter.
4)I jumped out the PTT to ground and teh relay pulled in and the FT-817 stopped receiving indicating the relay did pull in. When I transmitted with 1 watt this time I got a blip on the watt meter and then NOTHING at all out of the amp. Note: I disconnected the PTT and tried it again and the green transmit light came on, the relay pulled in and I got the same blip on the watt meter and then nothing.
5) I did check the voltage regulator U1 with the unit on. In the grounded position it put out about 12.6 volt and when I turned pot on R15 the voltage dropped to around 7 volts. I did put the jumper between filter in and out.
6)Any suggestions. Could it be Q3 or Q4? The soldering looks OK but maybe I messed up some place.I looked very carefully to see if something was shorted but I couldn't see anything
Any help would be greatly appreciated.
Pete
AB2KG

Pete .. use 5430-2205 for the standoffs, they are 1 inch.
I don't have the instructions for WA2EBY's filter board handy but what you suggest sounds OK as the 160 & 80 have the most turns. I installed the thermo pads against the cabinet and used the isolation hardware from the mounting kit. The mounting screws should be isolated from the transistor tab.
Jim

Jim,
Thanks.
So far so good. I have the amp board completed.
I'm going to use power poles for my power commection and will mount them with the two BNC's on the back side. Note: You get two wire sizes with the inductor package. I guess you use the 24 ga on 160 and 80, and 22 ga on the rest. Also the spacers spec'd out are too short. It looks like you need 1" and not 1/4" as spec'd in the article. Also can you give instructions on how the heat sink material and isolation kits are installed for Q3&4. What goes againt the cabinet? Thanks.
Pete
AB2KG

The TBD capacitor is not used.

The values shown in the schematic are correct. They are not critical, a 3.3K or 4.7 K should work OK for both.

Jim

1)Has there been a value for the capacitor (TBD) located on the component layout between Q3&4 and the pads below T1, or is this capacitor needed?
2)There are two R14 resistor shown on the schmatic. One near Q2 and on by the light emitting diode D10. I assune the R14 near Q2 should be 4.7K as shown and not as listed in the component list as 3.3K.
Pete
AB2kg

I have 3 questions:
1) Should the #18 and #24 teflon wire be solid or stranded?
2) Where can you get just a foot of each size. Every place I've tried sells it by the hundred feet and the #18 is over $100.00 for 100 feet.
3) What gauge wire do you recommend for the rest of the hook up wire...#22 or #24 solid copper.
I'v been successful in getting everything else except for the teflon wire.
Thank you.

On inspecting my FAR Circuits boards, I found a problem with the Filter board.

On the component side ground plane, the etch is not relieved for clearance around the Input side of the 30m (D) filter connections for Relay K6 Common, C1 and L1.

These need to fixed with a Dremel or a knife.

Also there is superfluous clearance around Out Relay K1 N.C. which is grounded.

-Duncan

P.S. No response to my query about choke RFC1.

Steve,
T2 is formed with 2 ferrite cores with brass tubes inside. These tubes form the primary. The tubes are soldered to PC Boards at each end. On one end the etch is separated to form the two ends of the primary. On the other end the etch is joined to complete the path between the tubes and to provide the center tap.

See the images: http://www.rfparts.com/combiner.html#Broadband

Edited by author 07-08-2003 02:38 PM
Could you elaborate a bit on the winding of T2? I see the Secondary and Sense winding shown on the drawing, but not the Primary. The instructions say to wind the secondary first and mount it to the PCB. That's the last mention of it I could find. Thanks.
   Steve

RFC1 is given as RF Parts VK200-3R, with radial leads.
The PC Board diagram and photographs in QST seem to show the axial leaded part, VK200-3A.

Which is recommended?

See: http://www.rfparts.com/choke.html#ferrite

-Duncan

Edited by author 06-16-2003 08:38 AM
From K4STN ... a note regarding R1 & R2
R1 AND R2 ARE CORRECT AS SHOWN ON THE SCHEMATIC AND REVERSED IN THE PARTS LIST.

JIM

FROM ARNOLD...
Mouser has no listing for the 560 pf and the
820 pf cap at 500 v.----only 300v..
Sugestions.....


JUMP UP TO THE NEXT SERIES ...
560 pF, 5982-19-500v560
820 pF, 5982-19-500v820

JIM

IN RESPONSE TO QUESTIONS FROM WB9NLZ ...

Hi Tim,
Check the FARA web site listed in the article on page 38, top-center. The direct link is:
http://www.quicktopic.com/21/H/WSSE3raN8yL

The RF board has several holes which are pinned and soldered around it's perimeter (see Fig. 5). Four screws hold the RF board to the case - these can be seen on the top of the box in the lead photo. Where the screws come through the case use a couple of 4-40 washers as spacers so the board sits flat, otherwise it will bend the board due to the 'pinned' holes.

My reference to the thermal insulator pads was incomplete - try the following Mouser part number 526-NTETP0006, they come 5/pkg. The other hardware is the insulating hardware for the transistor mounting screws. The heatsink needs to be tapped at the locations noted - two screws hold the heatsink to the case the others are for the diode and transistors.

Hope this is helpful.

Jim

FILTER BOARD BYPASS CAPACITORS -
SCHEMATIC CALLS FOR A .01uF (140-100Z5-103Z)
PARTS LIST HAS 140-100Z5-102Z, A .001uf

IT'S USED AS A BYPASS, I HAVE USED BOTH IN DIFFERENT BUILDS. YOU CAN USE EITHER AS IT'S NON CRITICAL.

CIRCUIT BOARDS - comments from FAR Circuits...
The boards are $18.00 per set with $2.00 shippng charge. I sold all I have at Dayton but will have more made this week.
To order just refer to the FARA amp in june '03 QST.

ADDITIONAL PART CHANGES ... SEE BELOW

Just the article I have wanted to see. It should be fun to construct and make a fine companion to the FT-817 for those times when a small boost would be appreciated. Thanks very much for the effort.
 
Noticed three small items that may be in error. The T-1 core may be a BN-43-302, since Amidon has that part number, but not 303. A resistor called as a 30BY250-120 may be a 30BJ250-120. And the Component View Board (download from arrl) shows U-1 called as Q5, which may confuse someone for a minute. Do you know of any real problems that I should know about before I get into this ? Thanks very much for an exciting project.
 
Bill Durrett, K4STN

THE CORE IS NOTED.

YOU HAVE THE CORRECT PART NUMBER FOR THE 120 OHM RESISTOR AS
30BJ250-120.

Q5 ON THE PARTS PLACEMENT IS U1 ON THE SCHEMATIC, IT WAS CHANGED WHEN THE SCHEMATIC WAS PRINTED.

THANKS,

JIM

Edited by author 05-16-2003 09:07 AM
I RECEIVED THE FOLLOWING NOTE FROM RAY. THERE WAS A 1 YEAR LAG BETWEEN THE ARTICLE BEING SUBMITTED AND IT BEING PUBLISHED. AS A RESULT THERE ARE A FEW PART NUMBER CHANGES AND A TYPO TO BE CORRECTED.

Hi Jim:

I've read, with great interest, your write-up covering the 'FARA HF Project' in June QST. Just the ticket to add to my (on-order) "PSK-20" from Small Wonder Labs.I've started the parts search...and have run into a few "box canyons".
So I'm asking for your suggestions / work-arounds / alternates.

1) From Mouser these parts...D6, the FES8JT sells for about a buck each,but with a 500 minimum order (definitely a lifetime-plus supply)...K1, the 551-MR-12USR, doesn't exist...neither does the LP filter switch, 10-YXX026

Diode, 511-STTA806D
K1, 551-MR82-12USR
SWITCH, 633-MRY106A

2) From Amidon...T1, core BN-43-303 "not available at this time" and no forecast available, either. Maybe there's a suitable core from RF Parts instead?

TYPO, BN-43-302

3) From RF Parts...T2, "T-3/4", doesn't exist but there is a "T-.75" that may be the same thing (3/4 = 0.75)?

YES, THE T-.75 APPEARS TO BE THE NEW PART NUMBER

Your comments would be most appreciated!

Thanks, and 73,

Ray NJ0G

THANKS RAY - HOPE THIS HELPS!
JIM, WA1GPO

Welcome to the new FARA Forum discussion section on the FARA HF Amplifier appearing in the June 2003 QST issue. The HF Amp is a project created by FARA member Jim Valdes, WA1GPO, and is a compact amp for low power HF rigs like the Yaesu FT-817.