I guess I didn't realize that they were that expensive. I got my TR7 with vfo and power supply traded My fl2100b Amp for it as I ever used it. I guess I got lucky. I hardly ever use the vfo, maybe I should sell it lol.?
On Sat, Jan 20, 2024, 4:04?PM K6OXN Bob < bobk6oxn@...> wrote: I now have a Noble Radio NRV7 that is working like a champ with my TR7. I still have a want for an RV75 as it is a complement to my Drake 7 line station. Can wait now.? Thanks.
73? Bob
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I now have a Noble Radio NRV7 that is working like a champ with my TR7. I still have a want for an RV75 as it is a complement to my Drake 7 line station. Can wait now.? Thanks.
73? Bob
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Re: Drake W4 wattmeter woes...
If R1 goes high in value, you will get less signal to your meter.? It¡¯s the only resistor that¡¯s common to both the power ranges.
?
Clint, VE3CMQ
?
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From: [email protected] <[email protected]>
On Behalf Of Mike Bryce via groups.io
Sent: Saturday, 20 January 2024 09:21
To: [email protected]
Subject: Re: [DRAKE-RADIO] Drake W4 wattmeter woes...
?
Thanks, Clint,
I remember checking that value, but will re-check it to make sure.
My issue seems to be I can¡¯t get the meter to read high enough. Even with 150W, I can¡¯t set the meter to much over 90W on its scale.
For such a simple circuit, it sure is causing me lots of issues.
Just for grins, I¡¯m going to replace C5 and C4. I only recall once or twice in my life that I¡¯ve found a bad ceramic capacitor, but I¡¯m drawing straws now.
?
"The eye is always caught?by the light, but shadows?have more to say"
On Jan 20, 2024, at 8:40 AM, Clint VE3CMQ <ve6cmm@...> wrote:
?
Don¡¯t forget that R1 is in the circuit.? If that goes high in value, it could throw everything off.
PIN diodes should work well in these meters.? They work well into the VHF range and have low forward voltage drops.? The 1N34 and other geranium diodes were used because they performed better than silicon did at the
beginning.? Things have changed now.
?
|
Re: Drake W4 wattmeter woes...
I found some at Jameco. They¡¯re 1N270 diodes
mike wb8vge
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On Jan 20, 2024, at 1:20 PM, K6OXN Bob < bobk6oxn@...> wrote:
Just did a search and cannot locate any of the proper diodes. I do have an electronic supply house nearby and they have in stock 93 of the 1N295H diodes.? They are Electronic Expeditors in Camarillo? phone 805-987-3344 ask for Jesse and he might be able to help. They won't be open until Monday the 23rd after 10:00 am PST.
73? Bob
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Re: Drake W4 wattmeter woes...
Just did a search and cannot locate any of the proper diodes. I do have an electronic supply house nearby and they have in stock 93 of the 1N295H diodes.? They are Electronic Expeditors in Camarillo? phone 805-987-3344 ask for Jesse and he might be able to help. They won't be open until Monday the 23rd after 10:00 am PST.
73? Bob
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Re: Drake W4 wattmeter woes...
I did an Amazon search for 1N34A, and came up with several hits. Unfortunately,
they're apparently not real germanium diodes, but rather hot carrier diodes.
- Jerry, KF6VB
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Re: Drake W4 wattmeter woes...
Yes my problem seems to be just like yours. One of the diodes was open which caused the meter to not work. I found some of the diodes and replaced both of them. That fixed the problem. Let me look to see if I have any more of them and they are yours.
73? Bob
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Re: Drake W4 wattmeter woes...
Since you have one that works fine, why not use that one to garner the correct
voltages & waveforms at each point of the circuit?
- Jerry, KF6VB
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On 2024-01-20 07:27, mike bryce wrote: Ralph,
I¡¯m going by the schematic that I uploaded.
the instructions call for setting the 200W scale first, then the 2000W
scale. That¡¯s what Iv¡¯e been doing
Yes, cleaned the meter¡¯s terminals and cleaned the selector switch
mike wb8vge
On Jan 19, 2024, at 10:48 PM, Ralph Mowery via groups.io [1]
<ku4pt@...> wrote:
Did you put the meter for reverse and adjust the capacitor for
minimum first ?
There are 2 schematics that I know of for the wattmeters are you
sure you are looking at the correct one ? I don't recall the
difference but think that it has to do with the veritable resistors
where you have to set one range and then the other range and the
other schematic you can adjust either range separately. The
schematic you have is where you set the 200 watt range first and
then set the 2000 watt range.
Did you try loosening and then tightening the nuts on the meter
wiring ?
Ralph ku4pt
Links:
------
[1]
[2] /g/DRAKE-RADIO/message/75654
[3] /mt/103840961/243852
[4] /g/DRAKE-RADIO/post
[5] /g/DRAKE-RADIO/editsub/243852
[6] /g/DRAKE-RADIO/leave/12260778/243852/767576506/xyzzy
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Re: Drake W4 wattmeter woes...
Ralph,
I¡¯m going by the schematic that I uploaded.
the instructions call for setting the 200W scale first, then the 2000W scale. That¡¯s what Iv¡¯e been doing
Yes, cleaned the meter¡¯s terminals and cleaned the selector switch
mike wb8vge
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Show quoted text
On Jan 19, 2024, at 10:48 PM, Ralph Mowery via < ku4pt@...> wrote:
Did you put the meter for reverse and adjust the capacitor for minimum first ?
There are 2 schematics that I know of for the wattmeters are you sure you are looking at the correct one ?? I don't recall the difference but think that it has to do with the veritable? resistors where you have to set one range and then the other range and the other schematic you can adjust either range separately.? The schematic you have is where you set the 200 watt range first and then set the 2000 watt range.
Did you try loosening and then tightening the nuts on the meter wiring ?
Ralph ku4pt
_._,_._,_
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Re: Drake W4 wattmeter woes...
Yup, been there and done that.
The transmitter is working fine. I have a Bird in line with the W4.
Like I said in the original post, some meters peg with 100W and I can¡¯t adjust them to the correct readings while some don¡¯t show power at all or very low reading that I can¡¯t adjust.
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On Jan 20, 2024, at 9:16 AM, Steve Wedge, W1ES/4 via < w1es@...> wrote:
Whenever I see something like this happening with multiple UUT¡¯s, I check the obvious: is the transmitter outputting? Are the meters being fed correctly (rig to input, load to output)? ?We all do silly things from time to time.
Don¡¯t hate me¡
73,
Steve Wedge, W1ES/4
Time flies like an arrow. Fruit flies like a banana.
|
Re: Drake W4 wattmeter woes...
Thanks, Clint,
I remember checking that value, but will re-check it to make sure.
My issue seems to be I can¡¯t get the meter to read high enough. Even with 150W, I can¡¯t set the meter to much over 90W on its scale. For such a simple circuit, it sure is causing me lots of issues.
Just for grins, I¡¯m going to replace C5 and C4. I only recall once or twice in my life that I¡¯ve found a bad ceramic capacitor, but I¡¯m drawing straws now.
Mike Bryce
"The eye is always caught?by the light, but shadows?have more to say"
toggle quoted message
Show quoted text
On Jan 20, 2024, at 8:40 AM, Clint VE3CMQ < ve6cmm@...> wrote:
Hi Mike, ? Don¡¯t forget that R1 is in the circuit.? If that goes high in value, it could throw everything off. ? PIN diodes should work well in these meters.? They work well into the VHF range and have low forward voltage drops.? The 1N34 and other geranium diodes were used because they performed better than silicon did at the beginning.? Things have changed now. ? 73, Clint, VE3CMQ ?
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Re: Drake W4 wattmeter woes...
µþ´Ç²ú¡
did you have the same problem as I have, with the issue with setting the meter correctly?
One meter, I can¡¯t set the calibration, and on some the meter pegs and the trimmers have no control?
Mike wb8vge
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On Jan 20, 2024, at 12:33 AM, K6OXN Bob < bobk6oxn@...> wrote:
Sorry I should have done a little more research on those items. I replaced the diodes in my W4 last year and it worked great after the diodes were replaced. Still works like it should. Was able to adjust it using my Bird 43 as a reference.
73? Bob
|
Re: Drake W4 wattmeter woes...
Hi Clint
A PIN-diode won't work for shortwave frequencies and higher, because the charge carriers (electrons and holes) are slow. Above approx. 1-10 MHz a PIN-diode appears as a resistor:
Quote: "...The wide intrinsic region makes the PIN diode an inferior (one typical function of a diode), but it makes it suitable for attenuators...The PIN diode obeys the standard diode equation for low-frequency signals. At higher frequencies, the diode looks like an almost perfect (very linear, even for large signals) resistor..."
.
But at lower radio frequencies you could use a zero-voltage-threshold MOSFET "rectifier":
High Sensitivity Crystal Set
Build a ¡°crystal radio¡± that does not require an outside antenna or ground
by using a new zero-voltage-threshold MOSFET.
Bob Culter, N7FKI
http://www.arrl.org/files/file/Technology/tis/info/pdf/culter.pdf
Datasheet:
ALD110900APAL 500 ohm
ALD212900, PRECISION N-CHANNEL EPAD? MOSFET ARRAY
DUAL HIGH DRIVE ZERO THRESHOLD? MATCHED PAIR
14 ohm
Datasheet:
--
best regards,
Glenn, OZ1HFT
|
Re: Drake W4 wattmeter woes...
Whenever I see something like this happening with multiple UUT¡¯s, I check the obvious: is the transmitter outputting? Are the meters being fed correctly (rig to input, load to output)? ?We all do silly things from time to time.
Don¡¯t hate me¡
73,
Steve Wedge, W1ES/4
Time flies like an arrow. Fruit flies like a banana.
On Sat, Jan 20, 2024 at 8:40 AM, Clint VE3CMQ < ve6cmm@...> wrote:
Hi Mike,
?
Don¡¯t forget that R1 is in the circuit.? If that goes high in value, it could throw everything off.
?
PIN diodes should work well in these meters.? They work well into the VHF range and have low forward voltage drops.? The 1N34 and other geranium diodes were used because they performed
better than silicon did at the beginning.? Things have changed now.
?
73, Clint, VE3CMQ
?
?
Hi, Ron,
already checked the meter movements and they all seem to be working fine.
I¡¯ve been poking around with one of the meters.
Trimmer R4 sets the calibration for the 200W scale.
Voltage from D1, (from the pickup generated by D1) goes through R4 to the meter switch and then through the 2.2K resistor to the meter. It¡¯s that simple! However, I can¡¯t set the meter to 100W with 100W from the transmitter (using a bird
wattmeter and correct slug)?
When the 2000W position is selected, voltage ?goes through R4, then R3 and R2. R2 set the 2000W scale.
I put in a 5K trimmer for R4, and I can somewhat set the meter. Even with R4 out of the circuit, the meter can¡¯t quite make full 100W deflection.?
What¡¯s that mean? I don¡¯t know. I suspect the D1 isn¡¯t up to snuff, it tests fine. Resistor R5 is good, too.
So far, I can¡¯t find any of the 1N295 diodes, although I¡¯m sure the 1N34A diodes will work. I don¡¯t have any of those either, and the chinese imports are $2 a pop.
It¡¯s a real head scratcher!
|
Re: Drake W4 wattmeter woes...
Hi Mike,
?
Don¡¯t forget that R1 is in the circuit.? If that goes high in value, it could throw everything off.
?
PIN diodes should work well in these meters.? They work well into the VHF range and have low forward voltage drops.? The 1N34 and other geranium diodes were used because they performed
better than silicon did at the beginning.? Things have changed now.
?
73, Clint, VE3CMQ
?
toggle quoted message
Show quoted text
From: [email protected] <[email protected]>
On Behalf Of Mike Bryce via groups.io
Sent: Friday, 19 January 2024 19:25
To: [email protected]
Subject: Re: [DRAKE-RADIO] Drake W4 wattmeter woes...
?
Hi, Ron,
already checked the meter movements and they all seem to be working fine.
I¡¯ve been poking around with one of the meters.
Trimmer R4 sets the calibration for the 200W scale.
Voltage from D1, (from the pickup generated by D1) goes through R4 to the meter switch and then through the 2.2K resistor to the meter. It¡¯s that simple! However, I can¡¯t set the meter to 100W with 100W from the transmitter (using a bird
wattmeter and correct slug)?
When the 2000W position is selected, voltage ?goes through R4, then R3 and R2. R2 set the 2000W scale.
I put in a 5K trimmer for R4, and I can somewhat set the meter. Even with R4 out of the circuit, the meter can¡¯t quite make full 100W deflection.?
What¡¯s that mean? I don¡¯t know. I suspect the D1 isn¡¯t up to snuff, it tests fine. Resistor R5 is good, too.
So far, I can¡¯t find any of the 1N295 diodes, although I¡¯m sure the 1N34A diodes will work. I don¡¯t have any of those either, and the chinese imports are $2 a pop.
It¡¯s a real head scratcher!
|
Re: Drake W4 wattmeter woes...
Hi Mike
Search for 1N295 here:
https://www.nteinc.com/search.php
Found NTE109.
Datasheet NTE109:
https://www.nteinc.com/specs/100to199/pdf/nte109.pdf
How to find NTE distributors:
https://www.nteinc.com/2-ways-to-purchase.php
You can a few maximum ratings on 1N295 here:
https://english.electronica-pt.com/components-cross-reference?ref=1n295
--
best regards,
Glenn, OZ1HFT
|
Hi Bob
How about buying/building these DDS VFO:
Noble Radio NRV7 Remote Digital VFO for Drake TR-7:
https://www.eham.net/reviews/view-product?id=12990
NRV7 Remote DDS VFO/Station Accessory:
https://nobleradio.com/page2.html
Quote: "...
The NRV7 can be controlled from its USB interface by most common PC based rig control programs that can be set for the FT-857 CAT command set.
..."
NRV7 Remote VFO.
Station Accessory for the Drake TR7.
No schematic:
http://www.puertobalsillas.com/radio/Drake/NRV7_WB2UJS.pdf
NRV7B Enhanced DDS VFO/Station Accessory for the Drake TR7:
https://nobleradio.com/page3.html
-
i0cg:
DIGITAL VFO
INSTRUCTION MANUAL
(Software V1.5)
Last update : December 1 2004
DDS-4, DDS-7 (page 21)
trafo after AD9951/AD9954 (good DDS; uses 14-bit DAC)
http://www.i0cg.com/dds-4.pdf
https://www.nitehawk.com/rasmit/vna_dds/dds-x_v1_6.pdf
Quote: "...
[page 21]
CONNECT DDS-7 TO DRAKE TR7 TRANSCEIVER
..."
AD9951 DDS & DDS-4 digital VFO:
http://www.i0cg.com/ad9951.htm
Quote: "...
CAT control via Ham Radio Deluxe,
..."
-
N4YG DDS VFO (uses ?-bit DAC):
http://www.df4nw.de/
Quote: "...
DDS VFO by? N4YG/DF4NW
..."
Floyd Sense, K8AC
February 27, 2012 (uses ?-bit DAC)
The N4YG DDS VFO and the Drake TR7:
http://www.wb4hfn.com/DRAKE/DrakeArticles/TR7-Digital_VFO_Upgrade/N4YG-VFO-Installation.pdf
http://www.puertobalsillas.com/radio/Drake/N4YG_VFO_TR7.pdf
https://archive.org/details/manualzilla-id-6022726
-
Uses AD9850 (uses 10-bit DAC):
Dual Digital DDS VFO for Ten-Tec Omni, Argosy, Corsair, Drake TR-7, Heath SB-104(A) and
Other Transceivers Using a 5.0 - 5.5Mhz VFO:
https://k3jls.net/box.html
--
best regards,
Glenn, OZ1HFT
|
T4 Keying Voltage and Current
Does anyone have a list handy of the keying voltage and *current*
on the CW key line for the various T4 transmitters? I've gone over
all the manuals, and the usual web pages, but this doesn't seem to
be documented anywhere.
I can measure the voltage easily enough, but not one of the meters
in my collection will measure the current. The Simpson gets close,
but they say don't measure current where the voltage exceeds 25V,
which I'm sure the keying line does.
--lyndon
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Re: Drake W4 wattmeter woes...
Sorry I should have done a little more research on those items. I replaced the diodes in my W4 last year and it worked great after the diodes were replaced. Still works like it should. Was able to adjust it using my Bird 43 as a reference.
73? Bob
|
Re: Drake W4 wattmeter woes...
Lots of vendors selling 1N34A even if Mouser doesn't stock them.
On Friday, January 19, 2024 at 10:45:05 PM EST, Mike Bryce <prosolar@...> wrote:
µþ´Ç²ú¡
Those parts are not diodes¡some kind of SMD device for control circuits.?
The 1n34a is listed as obsolete?
Mike
Btw. Found some 1n270 at Jameco
Knowledge is knowing a tomato is a fruit; Wisdom is not putting it in a fruit salad. ? On Jan 19, 2024, at 10:25 PM, K6OXN Bob <bobk6oxn@...> wrote:
?link for 1N34A??
73? Bob
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K8CCA