[50mhz] Workman TVI-2K Low Pass Filter - any good?

Thu Aug 23 17:51:45 EDT 2007

~ 2dB insertion loss?!? Look at those curves again, its under .5 dB.

There are less pricy options if one has access to some test equipment. A 
pair of old Drakes can be tweaked; the Gavin "Maverick" is adjustable. These 
are often real cheap at hamfests.

I use a Waters 373-6 which is a true bandpass filter at the output of the 
transverter. It cleaned up all the birdies from a commercial site 1 mile 
away with FMBC, UHFTV, FAA and all sorts of 2 way stuff. It came off Ebay 
for $5.

Carl
KM1H

----- Original Message ----- 
From: "Bill W5WVO" <w5wvo at cybermesa.net>
To: <50mhz at mailman.qth.net>; <kr7o at vhfdx.com>
Sent: Thursday, August 23, 2007 5:06 PM
Subject: Re: [50mhz] Workman TVI-2K Low Pass Filter - any good?

> Yup. I run a DCI 8-pole bandpass filter built to pass 49-51 MHz. 
> (http://www.dci.ca/?Section=Products&SubSection=Amateur) I had them tune 
> it down a MHz from the usual default (50-52 MHz) to get the skirts even 
> further away from Channel 2. It ain't cheap -- but it is built like a tank 
> and is awesomely effective. Less than 2 dB insertion loss. It works fine 
> at 400W PEP output, though it is "officially" rated, very conservatively, 
> at 200W. Not only does it protect my receiver, it cleans up my transmitted 
> RF profile as well.
>
> Bill / W5WVO
>
>
> kr7o at vhfdx.com wrote:
>> Bill,
>>
>> You might also consider a single one of the ICE (or other) bandpass
>> filters if you have a single band (or separate 6M antenna input)
>> radio.  If you are only interested in 6m SSB, get the 50-50.5 MHz
>> filter (ICE also has a 50-54 MHz version).  Why expose DC to daylight
>> radios with RF outside where you are operating?  If you want to
>> operate outside of the filters range a simple transfer relay will
>> solve that problem (such as listening for TV carriers as propagation
>> indicators).
>> I am a fan of single band BP filters (where practical) as they are a
>> necessity for me when running legal limit with multiple radios on HF
>> thru 2m and antennas in close proximity, to keep unwanted out of band
>> RF from degrading and/or damaging (yes, blew an HF front end once
>> with a 6m yagi 10' above a tribander).
>>
>>
>>
>> At 09:28 AM 8/23/2007 -0400, jeremy-ca wrote:
>>> I use both the B&W and ICE on the home and cottage stations. They
>>> have excellent curves and can handle 1500W. Ive also found that the
>>> high power filters have much better rejection than the cheap ones.
>>>
>>> Carl
>>> KM1H
>>>
>>>
>>> ----- Original Message ----- From: "Bill Dzurilla"
>>> <billdz.geo at yahoo.com> To: "jeremy-ca" <km1h at jeremy.mv.com>;
>>> <sixclub at mailman.qth.net>; <smirk at mailman.qth.net>;
>>> <50mhz at mailman.qth.net> Sent: Thursday, August 23, 2007 8:38 AM
>>> Subject: Re: [50mhz] Workman TVI-2K Low Pass Filter - any good?
>>>
>>>
>>>> Thanks for the offer, Carl.  I don't own one.  Was
>>>> looking for a suitable filter for 6m and saw this on
>>>> eBay.  But DD7ZT says it's not for 6m so I'll pass on
>>>> it.  Any recommendations for a good one for 50 mhz?
>>>> 73,
>>>> Bill NZ5N
>>>> --- jeremy-ca <km1h at jeremy.mv.com> wrote:
>>>>
>>>>> Send me one and I'll put it on the VNA. You pay
>>>>> shipping both ways. I'd like
>>>>> to create a filter database.
>>>>>
>>>>> Carl
>>>>> KM1H
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> ----- Original Message ----- From: "Bill Dzurilla"
>>>>> <billdz.geo at yahoo.com> To: <sixclub at mailman.qth.net>;
>>>>> <smirk at mailman.qth.net>;
>>>>> <50mhz at mailman.qth.net>
>>>>> Sent: Thursday, August 23, 2007 12:52 AM
>>>>> Subject: [50mhz] Workman TVI-2K Low Pass Filter -
>>>>> any good?
>>>>>
>>>>>
>>>>>> Anyone used this filter on 50 mhz?  Does it work
>>>>> well?
>>>>>> Any comments about it?
>>>>>> 73, Bill NZ5N
>>>>>>
>>>>>>
>>>>>>
>>>>>>
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>>
>> 73, Robert KR7O/YB2ARO, DM07ba/OI52ee  (ex.  N7STU)
>> kr7o at vhfdx.com
>>
>> www.vhfdx.com (KR7O/YB2ARO homepages)
>>
>>
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